¥¥

¥

¥

The new three-in-one PTU200 tra n s-m i t t e r, which mea-

sures ba r o m e t r i cpressure, air temper-

ature and relativeh u m i d i t y, can be

used for estimatingthe effect of water

vapor on GPS coor-dinate measure-

m e n t s.

Designed for fa s t e rand more accura t ec a l i b ration ofhumidity instru-m e n t s, theHM K 15 calibra-tor is suitable forboth labo ra t o r yand field use.

Between the 4th and 12th centuries, dev o u tBuddhists carved rock temples in the Mo g a oGrottoes in Gansu Province, China. To pre-serve the wall pa i n t i n g s, the moisture contentof the temple walls is closely monitored usingVaisala’s HM44 structural humidity meas-urement set.

2 148/19982

Contents

3 President’s Column

H u m i d i t y

4 M ea s u ring Humidity in Confined

S p a c e s

5 Conserving Ancient Sites on China’s

Silk Road

8 HM44 Kit Helps Solve Floor Moisture

P r o b l e m s

10 Renovation and Humidity Monitori n g

Go Hand in Hand

12 B rick Drying Requires Careful

Humidity Control

14 Water Content Measurements Ke e p

Paper Machines Running Smoothly

16 The Many Faces of Water Va p o r

18 Easy and Reliable Calibration with

the HM K 15 Humidity Calibrator

21 H i g h -Quality Engineering Services for

the Most Demanding Customers

2 2 The HUM ICA P®

Celebrates Its 25th

A n n i v e r s a ry

2 3 Over and Above Pe rf o rmance for

Environmental Chambers

24 C l i m a t e -Control for Supercomputers

2 5 S h e rlock Holmes Would Be Im p r e s s ed

Vaisala in Brief

- We dev e l o p, manufacture and mark e t

products and services for environmental

and industrial mea s u r e m e n t s.

- Purpose of those measurements is to

provide basis for better quality of life,

cost savings, protection of environment,

i m p r o v ed safety and perf o rm a n c e .

26 Lo n g -Te rm Project to Monitor the

Conditions in the Todaiji Te m p l e

28 Vaisala’s Fo rmula for Success in China

Carbon diox i d e

30 High Indoor Air Quality with Minimum

Energy Costs

31 N ev e r -Ending Wi n t e r

3 3 N ew CO2 Products Complement the

GM20 Seri e s

P r e s s u r e

34 Th r e e - i n -One Transmitter for PT U

M ea s u r e m e n t s

3 5 A d v a n c ed Marine Monitori n g

Improves Navigation Safety

36 N e t w o rk Sensors for the Japan

M e t eorological Agency

39 Meeting Wi d e -Ranging Needs in

J a p a n

41 The PT B 2 2 0 TS Travels We l l

41 Product Training in To k y o

Q u a l i t y

4 2 A c h i eving Improvements through

M easurement and Process Analysis

- We focus on market segments where we

can be world lea d e r s, the preferred suppli-

e r. We pay high attention on customer sat-

i s f a c t i o n. Our main quality discipline is Prod-

uct Lea d e r s h i p. Competitive advantage is

e n h a n c ed by economies of scale and

s c o p e .

Cover photo:

Lehtikuva: Superstock

Temple of the Pure

Wa t e r, Kyoto

E d i t o r - i n -C h i e f :

M a rit Fi n n e

P u b l i s h e r :

Vaisala Oyj, P.O. Box 26

FI- 0 0 4 21 Helsinki,

FINL A ND

Phone (int. ) :

(+358 9) 894 91

Te l e f a x :

(+358 9) 894 9227

In t e rn e t :

h t t p : / / w w w. v a i s a l a. c o m

Design and Art w o rk :

N o n -Stop Studiot Oy

E d i t o r s :

Axioma Oy

P ri n t ed in Finland by

S ä v y p a i n o, Fi n l a n d

ISSN 12 3 8 - 2 3 8 8

a i sala has deep rootsin weather measure-m e n t s. Some 20years ago, we real-

ized that there were similarmeasurement needs in manyother areas, particularly ini n d u s t ry. In one form or anoth-e r, humidity is a key parameterin hundreds of applicationsthat have nothing to do withthe weather. Similarly, baromet-ric pressure and carbon dioxidemeasurements also have manyindustrial applications.

For weather applications, wesupply systems that match spe-cific customer needs, althoughthis doesn’t exclude the deliv-e ry of single instruments. Forindustrial applications, wefocus on measurement trans-m i t t e r s. Based on our compre-hensive knowhow in wide-r a n g-ing application areas, we canhelp our customers find theright measurement solution.System integration, however, isoutside our scope of expert i s e .I n s t e a d, we work closely withthe end users and system inte-g r a t o r s. We are realists in this

r e ga r d. As with many aspects ofindustrial systems, the job ofintegration is for the applica-tion specialists.

Structural humidity measure-ments and the measurement ofhumidity in oil are two interest-ing new applications of oure q u i p m e n t.

Faulty building practices andinsufficient ventilation or heat-ing can lead to problems withstructural humidity. Excessivehumidity in unseen parts of abuilding can lead to moldgrowth and, in turn, health haz-a r d s, allergies and structuraldamage. As the price of energyhas risen, more thermal insula-tion is being used in regionswhere heating is necessa ry.U n f o rt u n a t e l y, the risk of moldgrowth is often high in theses t r u c t u r e s. We have studied thisproblem at Va i sa l a, and nowsupply diagnostic measurementdevices to builders and buildingc o n t r a c t o r s.

Water in oil is an undesirableadditive. When oil is used as al u b r i c a n t, any added waterw e a kens its lubricating proper-

t i e s. With constant humiditym o n i t o r i n g, the problem canbe identified in time, andavoidable damage and down-time can be prevented.

Calibration and traceabilityto references are critical factorsin measurement reliability. Toensure continuous, high-q u a l i-ty operation, measurementinstruments require occasionalc a l i b r a t i o n. This applies even toinstruments with excellent sta-b i l i t y. In response to thesen e e d s, Va i sala also supplies cali-bration services and instru-m e n t s.

By providing excellent mea-surement solutions, we helpensure the reliability of our cus-tomers’ processes – and theirs u c c e s s.

Pe kka KetonenPresident and CEO

3148/1998

President’s Column■ ■ ■ ■ ■ ■

Wi de-R a n g i n gM e a s u re m e n tA p p l i c a t i o n s

V

¥4 148/1998

Focus on indoor air quality

Measuring Humidity in Confined Spaces

To d a y, the effect of healthy indoor air onc o m f o rt and well-being is well estab-l i s h e d. Va i sala offers an ideal choice forconstruction moisture detection in con-fined spaces: the HMP42, the thinnesthumidity probe on the marke t, and theHMI 41 digital indicator are a perfect pairfor accurate humidity measurements.

a i sala has launch e dthe world’s t h i n n e s thumidity probe.Only 4 mm (0.16 ” )

in diameter, the HMP42 has around and remarkably smallprobe structure that is opti-mized for measurements innarrow and confined s p a c e s.Together with the HMI 41 digitali n d i c a t o r, the probe is an idealsolution for construction mois-ture detection. The holerequired is so small that it c a n

be bored safely in the jointsbetween ceramic tiles, for exam-p l e , without damaging the tiles.

Humidity has a direc timpact on indoor airq u a l i t y

To d a y, an understanding of theindoor env i r o n m e n t, includingindoor air quality, is essential.There is growing public interestin this topic, which has beenwidely discussed and is increas-ingly applied to building codesand construction methods. Hu-midity is one of the most im-p o rtant criteria for indoor airquality and should be kept with-in certain recommended limits.When the relative humidity is40–50%, for example, health haz-ards are minimized.

If the humidity level is tool o w, viruses live longer and canenter the lungs more easily, con-veyed by dust particles in thea i r. Overly dry air also irritatesthe respiratory orga n s.

If the humidity is consistent-ly high, it can lead to problemswith bacteria and mold growth.Mold has become a serious p r o b-l e m, particularly in the nort h-ern countries where houses aresometimes too tightly con-s t r u c t e d. Condensation providesa good substratum for mold,w h i ch can quickly make housesuninhabitable. Mold growth canalso be an indication of moistured a m a g e .

A small leak can mean abig problem

Buying a house – new or old – isa major inv e s t m e n t. Buyers wantto be sure there is no moisturedamage in their prospectivehome. Older houses require spe-cial attention. Many moisture

Figure 1. Save those tiles! Drill a hole at the point indicated and use Vaisala’s 4 mm diameter probe.

Figure 2. Using a

HMP42 probe to

measure humidity

in a ba t h r o o m.

V

Irma Ylika n ga s, M. S c. (C h e m. E n g. )Product ManagerSensor Systems DivisionVa i sala HelsinkiF i n l a n d

5148/1998

problems may have occurredduring their lifetime: flooding,burst pipes or, as is often thecase, a leaking dishw a s h e r.

A dishwasher leak is a typicalproblem in both old and newh o u s e s. Because it can be diffi-cult to detect, the leak can con-tinue for a long time and causeextensive damage. In a homewith the ki t chen and living roomside by side, for example, thefirst indication of an undetect-ed dishwasher leak can be theloosening and discoloration ofthe parquet floor in the livingr o o m.

Using Vaisala t echnology to eva l u a t ethe damage

At this stage the problem can-not be undone, but the extentof the damage can be evaluatedusing the HMP42 to measurestructural humidity. Th a n ks tothe small 4-millimeter diameterof the HMP42, the probe canoften fit into existing holes,behind the baseboard, for in-stance, so there is no need to drillnew holes.

Va i sala’s HMP42 humidityprobe and the HMI 41 digitalindicator provide reliable humid-i t y m e a s u r e m e n t s. The probecan be used in temperaturesfrom -40 to +100 °C. The HMI 41has an easy-t o -read two-line liq-uid crystal display availablewith either metric or non-m e t r i cu n i t s. The collected measure-m e n t data can also be trans-ferred to a PC.

Small enough for a spider’s lair?

The small diameter of theHMP42 opens up new possibil-ities for accurate and reliablemeasurement of humidity inm a ny interesting and unusualp l a c e s. The most exotic appli-cation so far has been the mea-surement of the moisture levelin a spider’s lair. What the spi-der thought about Va i sala’s Ø 4mm humidity probe is notkn o w n !

C o n s erving Ancient Siteson China’s Silk RoadThe Getty Conservation Institute is in a global race against time to pre-s e rve the monuments, sites and artifacts that enrich our lives and provideinsight into the world’s most intriguing cultures. “The Institute is a leaderin applying new ideas and technologies to conservation problems, and inraising public awareness of the importance of conserv a t i o n,” says SeniorScientist Shin Maeka w a, who is currently taking part in the conserv a t i o nwork in the Mogao Grottoes in China. Va i sala’s HM44 instruments arebeing used for structural humidity measurements in the Grottoes.

■

he Getty Conserv a-tion Institute, basedin Los Angeles, isp a rt of the J. Paul

Getty Tr u s t, a private founda-tion dedicated to the visual art sand the humanities. The originof the Trust dates back to 19 5 3and the founding of the J. PaulGetty Museum.

Sustainable approach toheritage preserva t i o n

The Getty Conservation Insti-tute (G CI) works international-ly to enhance the appreciationand preservation of the world’scultural heritage for the enrich-ment of current and future gen-e r a t i o n s. The Institute under-t a kes conservation work at someof the world’s most import a n tcultural sites.

The GCI pursues an interdis-c i p l i n a ry approach, applyingsustainable solutions to her-itage preserv a t i o n. To advancethe philosophy and practice ofc o n s e rv a t i o n, the Institute gen-erates and explores new ideasand carries out research andapplications projects.

M r. Shin Maeka w a, M. S c.and P. E., works as a Senior

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Antti Korhonen, B. S c. (E n g. )Sales ManagerSensor Systems DivisionVa i sala West Coast OfficeI rvine, CA, US A

Photos Courtesy: Shin Maeka w a

Scientist at the Getty Conser-vation Institute. At the mo-m e n t, he is closely involved inthe fieldwork at the Moga oGrottoes in China. He con-ducts scientific research on thec o n s e rvation of movable andimmovable cultural objects.

“ My specialty is the monitor-ing and control of env i r o n-ments and microenv i r o n m e n t ssurrounding cultural art i f a c t s.We collaborate with local mu-seum professionals and sitemanagers to analyze problemsrelated to environmental issuesin order to develop and imple-ment solutions for the long-term preservation of objectsand sites. ”

M r. Maekawa has wide experi-ence in the preservation of theworld’s cultural heritage. As hee x p l a i n s, “I have taken part inm a ny international projectsaimed at conserving historicalo b j e c t s. These include the RoyalM u m my Collection at theEgyptian Museum and the origi-n a l manuscript of the Constitu-tion of India at the IndianParliament Library. I have alsow o r ked at archeological sitess u ch as the Tomb of Ne f e rt a r iin the Valley of the Queens, the

T

5148/1998

problems may have occurredduring their lifetime: flooding,burst pipes or, as is often thecase, a leaking dishw a s h e r.

A dishwasher leak is a typicalproblem in both old and newh o u s e s. Because it can be diffi-cult to detect, the leak can con-tinue for a long time and causeextensive damage. In a homewith the ki t chen and living roomside by side, for example, thefirst indication of an undetect-ed dishwasher leak can be theloosening and discoloration ofthe parquet floor in the livingr o o m.

Using Vaisala t echnology to eva l u a t ethe damage

At this stage the problem can-not be undone, but the extentof the damage can be evaluatedusing the HMP42 to measurestructural humidity. Th a n ks tothe small 4-millimeter diameterof the HMP42, the probe canoften fit into existing holes,behind the baseboard, for in-stance, so there is no need to drillnew holes.

Va i sala’s HMP42 humidityprobe and the HMI 41 digitalindicator provide reliable humid-i t y m e a s u r e m e n t s. The probecan be used in temperaturesfrom -40 to +100 °C. The HMI 41has an easy-t o -read two-line liq-uid crystal display availablewith either metric or non-m e t r i cu n i t s. The collected measure-m e n t data can also be trans-ferred to a PC.

Small enough for a spider’s lair?

The small diameter of theHMP42 opens up new possibil-ities for accurate and reliablemeasurement of humidity inm a ny interesting and unusualp l a c e s. The most exotic appli-cation so far has been the mea-surement of the moisture levelin a spider’s lair. What the spi-der thought about Va i sala’s Ø 4mm humidity probe is notkn o w n !

C o n s erving Ancient Siteson China’s Silk RoadThe Getty Conservation Institute is in a global race against time to pre-s e rve the monuments, sites and artifacts that enrich our lives and provideinsight into the world’s most intriguing cultures. “The Institute is a leaderin applying new ideas and technologies to conservation problems, and inraising public awareness of the importance of conserv a t i o n,” says SeniorScientist Shin Maeka w a, who is currently taking part in the conserv a t i o nwork in the Mogao Grottoes in China. Va i sala’s HM44 instruments arebeing used for structural humidity measurements in the Grottoes.

■

he Getty Conserv a-tion Institute, basedin Los Angeles, isp a rt of the J. Paul

Getty Tr u s t, a private founda-tion dedicated to the visual art sand the humanities. The originof the Trust dates back to 19 5 3and the founding of the J. PaulGetty Museum.

Sustainable approach toheritage preserva t i o n

The Getty Conservation Insti-tute (G CI) works international-ly to enhance the appreciationand preservation of the world’scultural heritage for the enrich-ment of current and future gen-e r a t i o n s. The Institute under-t a kes conservation work at someof the world’s most import a n tcultural sites.

The GCI pursues an interdis-c i p l i n a ry approach, applyingsustainable solutions to her-itage preserv a t i o n. To advancethe philosophy and practice ofc o n s e rv a t i o n, the Institute gen-erates and explores new ideasand carries out research andapplications projects.

M r. Shin Maeka w a, M. S c.and P. E., works as a Senior

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Antti Korhonen, B. S c. (E n g. )Sales ManagerSensor Systems DivisionVa i sala West Coast OfficeI rvine, CA, US A

Photos Courtesy: Shin Maeka w a

Scientist at the Getty Conser-vation Institute. At the mo-m e n t, he is closely involved inthe fieldwork at the Moga oGrottoes in China. He con-ducts scientific research on thec o n s e rvation of movable andimmovable cultural objects.

“ My specialty is the monitor-ing and control of env i r o n-ments and microenv i r o n m e n t ssurrounding cultural art i f a c t s.We collaborate with local mu-seum professionals and sitemanagers to analyze problemsrelated to environmental issuesin order to develop and imple-ment solutions for the long-term preservation of objectsand sites. ”

M r. Maekawa has wide experi-ence in the preservation of theworld’s cultural heritage. As hee x p l a i n s, “I have taken part inm a ny international projectsaimed at conserving historicalo b j e c t s. These include the RoyalM u m my Collection at theEgyptian Museum and the origi-n a l manuscript of the Constitu-tion of India at the IndianParliament Library. I have alsow o r ked at archeological sitess u ch as the Tomb of Ne f e rt a r iin the Valley of the Queens, the

T

6 148/1998

Great Sphinx at Giza, Ti w a n a kuin Bolivia, and currently theM o gao Grottoes and the Yunga n gGrottoes in the People’s Republicof China. ”

Hundreds of grottoesare still standing

Located approximately 2,000 kmwest of Beijing, near Dunhuangin Gansu Province, the Grottoesare on an ancient caravan route– known as the Silk Road – thatonce linked China with theWest and also conveyed Bud-dhism to China from India.

The practice of carving rocktemples dedicated to the Bud-dha also originated in India,spreading to China from thew e s t, with the carvings at theDunhuang site being some ofthe earliest examples. Betweenthe Western Wei Dynasty inthe 4th century and the YuanDynasty in the 12th century,generations of Buddhists creat-ed hundreds of rock temples inthe Mogao Grottoes. To d a y, thesedecorated grottoes are stillstanding in the 50-m e t e r -h i g h,2 -ki l o m e t e r -long cliff face.

The nearly five hundred (496)grotto temples that remain are

lined with painted clay sculp-tures and wall paintings thatdepict legends, portraits, cus-t o m s, and the arts of China overa thousa n d -year period. Th eM o gao Grottoes are carved in ahard packed conglomerate ofsand and gravel.

Long-term preserva t i o nof ancient artifacts

To achieve the long-term preser-v a t i o n of historical objects ands i t e s, groups of specialists worktogether to find an integrateds o l u t i o n. Mr. Maekawa explainshow valuable cave murals areexamined and preserv e d. “Th i sproject is a collaboration be-tween the Chinese State Bureauof Cultural Relics (a govern-mental organization in Beijing) ,the Dunhuang Academy (alocal custodial organization forthe Mogao Grottoes) and theGetty Conservation Institute.To provide a model for the con-s e rvation of China’s wall paint-i n g s, we selected a cave that rep-resents the typical extent of de-terioration in the Mogao Grottoesand other grotto sites along theancient Silk Road. In additionto environmental monitoring,

The staff of Dunhuang Academy, the local custodial organization for the

Mogao Gr o t t o e s, measure structural humidity using a Vaisala HM44 kit.

Shin Maekawa in front of the Gr e a t

Sphinx in Egypt.

The Mogao Grottoes viewed from the top. The Grottoes are carved in a hard pa cked conglomerate of sand and gra v e l.

Based on his earlier experi-e n c e s, Mr. Maekawa comments,“I have been using Va i sala’s r e l-ative humidity and temperaturesensors for the past nine years.They are considered an accu-rate and reliable choice for oura p p l i c a t i o n s. ”

7148/1998

we conduct moisture monitor-ing of the bedrock in the cave.”

“ We also use chemical analy-sis to study the materials usedfor the wall paintings, includ-ing the pigments, bindingm e d i a, mud plaster and bedrock.Documentation of the condi-tion of the wall paintings isdone very carefully. In the end,we have chosen conserv a t i o ntreatments that include consoli-dation of mud plasters and re-a t t a chment of painted layers. ”

HM 44 prov i d e sstructural humiditym ea s u r e m e n t s

As part of their work in theG r o t t o e s, Mr. Maekawa and hiscolleagues are using Va i sa l a ’ sHM44 structural humidity meas-urement set.

“ We are monitoring the mois-ture content of the highly inho-mogeneous conglomerate of sa n dand gravel in the Grottoes. Oure s t imates show that the mois-ture content of the bedrock isless than 10 per cent by volume.Because of the salt content ofthe bedrock, the accuracy andstability of the humidity meas-urements are critical. We con-

duct this monitoring at 13 sitesin the caves, so the cost per meas-urement must be reasonable.

“ To monitor the moisturecontent of the bedrock in theM o gao Grottoes, HM44 humid-i t y instruments have been in-stalled in holes drilled in thecave walls. We are not cert a i nwhether the moisture problemhas damaged the wall paint-i n g s, or if this is ancient dam-

age or an ongoing problem. Ifit is an ongoing problem, weneed to identify the source ofthe water for interv e n t i o n. ”

According to Mr. Maeka w a,sa t i s f a c t o ry results were ach i e v e din laboratory tests of the HM 4 4prior to the installation. “Wehave not had time, however, toevaluate the field measurementsy e t, and this process will con-tinue for the next two years. ”

The Mogao Grottoes viewed from the base. The site is located near Dunhuang in Gansu Province, China.

A Buddhist wall painting in cave 85.

■

8 148/1998

Howard M. Ka n a r ePrincipal ScientistGroup Manager Chemical Serv i c e sConstruction Te ch n o l o g yLa b o r a t o r i e s, Inc.S ko kie, Illinois, US A

HM44 Kit Helps So l veFloor Moist u re Pro b l e m s

C o n s t r u c t i o nTe ch n o l o g y

La b o r a t o r i e s, Inc.(CTL) has a well-

established reputationfor problem solving.

In recent years, thec o m p a ny has focused

on the problemscaused by excessive

moisture in floors. Forthis work, CTL uses

Va i sala’s HM44 meas-urement set, which is

optimized for measur-ing relative humidityin concrete slabs. Astheir experience has

s h o w n, the HM44 setis an easy-t o -use fieldkit that provides reli-

able and accurate meas-urements of structural

h u m i d i t y.

onstruction Te ch n o l-ogy La b o r a t o r i e s,I n c. (CTL) perf o r m sre s e a r ch, testing, and

consulting on a wide range ofconstruction materials. With a75 -year history, CTL is kn o w nworldwide for its solutions ofconstruction or perf o r m a n c ep r o b l e m s. The company has itsmain office and laboratories inS ko kie, Illinois, with 130 staff,including ch e m i s t s, geologists,c e r a m i s t s, arch i t e c t s, and civiland structural engineers.

Professional solutionsfor moisture problems

Since 1993, CTL staff have be-come increasingly involved introubleshooting moisture prob-lems in concrete floors withm o i s t u r e -sensitive floor cover-i n g s. Resilient floorings such asv i nyl sheet, vinyl compositiontile, linoleum, and viny l -b a cke dcarpet are all susceptible toproblems when excessive mois-ture and alkalies from the con-crete react with adhesive orp l a s t i c i z e r s. The problems rangefrom simple loss of adhesion toindoor air quality problemsfrom microbials and plasticizerb r e a k d o w n.

VOC-compliant adhesives(low concentrations of volatile

o r ganic compounds) for floorcoverings are increasingly usedto improve indoor air quality.H o w e v e r, many of these adhe-sives are subject to re-e m u l s i f i-cation when exposed to mois-ture from the original concreteb a t ch water, sub-slab ingress, orother sources. Problems such asdebonding and adhesive ooz-ing occur when concrete floorsare improperly made, inad-equately dried, or exposed to un-expected moisture ingress. Mois-ture measurement is an impor-tant tool for determining theroot cause of such problemsand recommending lasting solu-t i o n s.

A typical problem of

adhesive failure caused by

excessive moisture in

concrete. Some water-

based adhesives are re-

emulsifiable and can

become gummy losing

adhesion between the

concrete and the vinyl-

ba cked flooring.

The HM44 kit is used to

measure the moisture

profile in the concrete and

determine if the source of

the moisture is above or

below the concrete. In

some cases, the damage is

caused by excessive

flooding during cleaning.

C

9148/1998

Key role of structuralhumidity mea s u r e m e n t s

To inv e s t i gate moisture prob-l e m s, CTL staff have been us-ing the Va i sala HM44 set forrelative humidity (RH) meas-urement in concrete slabs.After many years of experiencewith older and larger relativehumidity probes, CTL consid-ers the HM44 set a well-d e-s i g n e d, easy-t o -use field ki t.Va i sala’s HM44 set was designedfor reliable and accurate hum i d-ity measurements of structuralmaterials such as concrete slabs.

According to the installationguidelines issued by manufac-turers of resilient flooring, allfloors should be tested for mois-ture before proceeding withflooring installation. In the U. S. ,these guidelines require a testusing a dish of calcium ch l o-ride, which is placed under aplastic dome on the concretes u rface. During a resting timeof 72 hours, the calcium ch l o-ride extracts moisture from theconcrete. The dish is weighedbefore and after exposure, andthe change in weight is ex-pressed as pounds of moistureemitted from the concrete over1000 square feet in 24 hours.This result, the moisture vaporemission rate (M V ER), is com-pared with product installations p e c i f i c a t i o n s, generally 3–5l b /1000 sq.ft./24 h (0.6–1. 0g / m2/ h). Although this test procedure has been used in theU. S. since the early 19 6 0 s, thetest results can be misleadingsince the MVER test does notindicate moisture levels deep inthe concrete.

C o s t - e f f ec t i ve andreliable mea s u r e m e n ta p p r o a c h

R e s e a r ch at CTL has shownthat the MVER test methodonly measures moisture in thetop inch or so (25 mm) of theconcrete, and the result isaffected by the ambient relativehumidity immediately prior tot e s t i n g. This finding led CTL tot ry the approach used in Swe-den and Finland, where mois-ture in concrete is measuredusing relative humidity probesat specific depths below theconcrete surface. By placing

Professional activities

CTL staff are also involved inthe American Society for Te s t-ing and Materials (ASTM)Committee F-6 on resilientfloor coverings. SubcommitteeF06.40 on Installation hasformed a Task Group to estab-lish test methods for using rela-tive humidity probes to deter-mine relative humidity in con-crete slabs.

CTL would like to thankGoeran Hedenblad at Lu n dU n i v e r s i t y, Lund Sweden, andmembers of Va i sala tech n i c a lstaff for the exchange of infor-mation on calibration and theuse of humidity probes for pre-cise measurements at high rela-tive humidity.

Howard Kanare is Pri n c i p a lScientist and Group Managerfor Chemical Services atConstruction Tec h n o l o g yLa bo r a t o ri e s, in Skokie, Il l i n o i s.M r. Kanare has been with CT Lsince 1979 and specializes in theinteraction of concrete floorsand floor coveri n g s. He has per-f o rm ed over 50 field and labo-r a t o ry investigations of floor cov-e ring perf o rmance issues, includ-ing moisture, mold and mildew,adhesive failure, plasticizerm i g r a t i o n, traffic loads, and con-crete integ ri t y. He consults onpre-installation testing and per-f o rmance troubleshooting.M r. Kanare is an active memberof ASTM F06.40 on Practices forInstallation of Resilient Fl o o rC o v e ri n g s. He is also chair ofTask Group 06.40.03 on mois-ture measurement in concrete.

Moisture can cause other problems than adhesion loss. This photo of a vinyl

sheet at a medical clinic shows severe discoloration caused by excessive

moisture and alkalies in the concrete.

A microscopical cross section of the

discolored vinyl reveals how

d i s c o l o ration progresses from the

bottom to the top of the vinyl and is

visible through the clear wear layer.

probes at several depths in aconcrete slab, it is possible toobtain a moisture profile that isnot strongly affected by currentweather conditions.

The following example ofthe economic value of Va i sa l aHM44 probe measurements isfrom a recent CTL inv e s t i ga-t i o n. A 26,000 sq.ft. (2,400 m2)addition to a municipal librarywas tested using the U. S. MVERmethod and found to emitgreater than 5 lb/1000 sq.ft./24h (1 g / m2/ h). On this basis,the carpet manufacturerrefused to permit installationfor fear of moisture problems,until the slab dried furt h e r.CTL placed Va i sala HM 4 4probes in six locations in theconcrete slab, and the resultsindicated that the concrete wasindeed drying properly. Th eM V ER test results had beend i s t o rted by recent high humid-i t y and changes in the ambienttemperature. The carpet manu-facturer agreed to permit instal-lation of the flooring, and theproject stayed on sch e d u l e .

Careful studies of RHm easurements inc o n c r e t e

To make accurate relative humid-i t y measurements in concrete,attention to details is critical.Holes drilled in concrete mustrest for at least three daysbefore measurement. Concreterelative humidity is disturbedby drilling and re-e q u i l i b r a t i o nis essential for accurate meas-u r e m e n t s. Swedish and Finn-i s h building standards requirenot more than 85% RH forinstallation of vinyl floor cover-i n g s. To calibrate probes accu-

rately at these and higher lev-e l s, CTL uses an env i r o n m e n-tal chamber controlled by wetand dry -bulb RTDs that are cali-brated traceable to the U. S.National Institute of Standardsand Te chnology (NIS T ) .

To inv e s t i gate flooring fail-ures in existing installations,CTL studies the age, history,and composition of the slaband subbase, the presence orabsence of a vapor retarder (‘m o i s-ture barrier’), and other factors.In the field we core selected

locations and examine the con-dition of the slab, subbase, andvapor retarder. We also exam-ine the geotechnical report s,inspect drainage conditions,and review the project manual,s p e c i f i c a t i o n s, and drawings. Inthe laboratory we perform teststo determine the water-c e m e n tratio of the hardened concrete.Ne x t, we look at the drying his-t o ry of the slab and compareactual and predicted moisturel e v e l s. The predicted levels arebased on published work andCTL staff experience. We thenwrite conceptual repair recom-m e n d a t i o n s, followed by de-tailed plans and specifications.CTL staff supervise or inspectrepairs to assure that moistureproblems will not recur. ■

10 148/1998

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Old brick buildings suffer in excessive humidity, which causes themto deteriorate before their time. The 250-y e a r -old Sveaborg Fortress isa striking example of an 18th century stone and brick structure. Tomark the anniversa ry of the fort r e s s, which dates from 1748, a majorrenovation is now underw a y. As part of the project, Va i sala has sup-plied the humidity measurement instruments for inv e s t i gating theeffects of moisture on old brick walls.

ocated on five largeislands off the coastof Helsinki, theSveaborg Fortress is

the largest sea fortress in thew o r l d. This year, it is celebrat-ing its 250th anniversa ry.

In the 18th century, Finlandwas part of Sweden, and thef o rtress was built to protectH e l s i n ki against attacks fromthe sea. Surrounded by stoneand brick walls and bastions,the fortress provided the Swed-ish navy with a safe harbor anda place for shipbuilding andr e p a i r s.

To d a y, about 900 people liveon the islands. The fortress is amuseum and an active venuefor cultural events, includingsummer theater perf o r m a n c e s.As a monument to militarya r chitecture, the fortress isunique in the world. It is in-cluded on the Unesco worldheritage list.

Moisture causes cracksin old bricks

Renovation of one part of thef o rtress – Tenaille von Fersen, at w o -s t o ry brick building withcasemates – began in 1996. Th esame year, Ki i n t e i s t ö a u t o m a t i oK&K delivered the first Va i sa l ahumidity and temperature trans-m i t t e r s for the project. They arebeing used to study the effectsof moisture on old brick walls.

In old structures, mold spreadseasily in damp conditions andcan ruin brick walls. By control-l i n g the humidity level, moldgrowth and the resulting dam-age to the brick work can bep r e v e n t e d.

R e n ovation andHumidity MonitoringGo Hand in Hand

At the 250-year-old Sveaborg Fortress:

R e n ovation andHumidity MonitoringGo Hand in Hand

To d a y, the Sveaborg Fortress is included on the Unesco world heritage list.

Managing Director

Kari Kumpulainen

from Kiinteistö-

automatio K&K

chose Va i s a l a ’ s

humidity tra n s m i t t e rs

for the Sveabo r g

Fortress project.

LL

11148/1998

As Mr. Kari Ku m p u l a i n e n,Managing Director of Ki i n t e i s t ö-automatio K&K, explains, bricksgradually disintegrate as theyage and cracks can easily occur.During recent years, the Te n a i l l ebuilding has not been heated,so the humidity levels insidethe building have been veryh i g h. As a result, the one-m e t e rt h i ck brick walls are sufferingfrom brick plague. Now thatthe Tenaille is under renova-t i o n, the building has to beh e a t e d.

The relative humidity levelin the old brick walls is veryc r i t i c a l. To prevent damage, itshould be kept below 60–80per cent. Otherwise, salts fromthe bricks leech to the surf a c e ,and the bricks slowly start todisintegrate. Winter weather isp a rticularly hard on the bricks,especially if they are wet.

Re s earch requires higha c c u r a c y

The first delivery for the proj-e c t, six HMP 2 31 transmitters,was made in 1996. This was fol-lowed by three HMP 2 31 andtwo HMP 143 humidity andtemperature transmitters in early19 9 8 .

Installed in a test ch a m b e r,the Va i sala transmitters moni-tor and measure relative humid-i t y and temperature both in thebuilding and at various depthsin the brick walls. The humid-

ity and temperature measure-ments are collected every hourand sent to the control centerof the Fort r e s s. The databaseon the humidity and state ofdisintegration of the bricks isbeing used in the research proj-e c t, which will continue fortwo more years.

M r. Kumpulainen has worke dwith building automation since1983, and he knows Va i sala’s hu-m i d i t y products well.

“ Va i sala’s transmitters werechosen for this project in orderto meet to our customer’s de-mands for high measurementa c c u r a cy and reliable perf o r-mance,” he explains. “Th eSveaborg Fortress has been andwill be a special challenge forus – and an interesting project. ”

As an employee of the Gov-erning Body of Sveaborg, Mr.Petri Koiranen represents thee n d -u s e r. He is responsible forthe humidity transmitters atthe Fort r e s s. “I have usedVa i sala transmitters since 19 9 6 ,and I am satisfied with theirp e rformance: they have beenboth accurate and reliable,” hesa y s.

Facts about the Te n a i l l evon Fe r s e n

Completed in 1776, the Te n a i l l evon Fersen is a two-s t o ry brickbuilding with casemates, situat-ed below a terreplein. All thecasemates were made of brick,

and divided into two stories byb e a m s. At the eastern end ofthe structure, there was a largec r e s c e n t -shaped casemate forthe horse-powered mill, and atthe western end, a large maga-z i n e -casemate above the pumphouse. A bake ry was in be-t w e e n. The defense wall of theTenaille, facing nort h, is 14 0meters long and has a maxi-mum height of 24 meters.

The casemate is a vaulted,b o b -roof room in a bastion. Itwas meant for housing guns fors h o rt -range defense. The bas-tion is the basic unit of thedefense fort r e s s, while the tenailleis a defense work consisting oftwo walls at an angle to eacho t h e r.

The Helsinki-basedKiinteistöautomatio K&Ks e l ec t ed and installedVaisala’s humidity trans-mitters in the Tenaille vonFe r s e n. The Svea bo r gFo rtress has been theircustomer since 1995. Th ecompany has been incharge of all buildingautomation projects atthe Fo rt r e s s, including theair conditioning systems.E s t a b l i s h ed in 19 9 0 ,Kiinteistöautomatio K&Kcurrently employs six peo-ple. Its main activities areconstruction automationp r o j ects in Fi n l a n d, usingthe Caradon Trend Ltd’sTrend systems.

Vaisala has supplied the humidity measurement instruments for investigating

the effects of moisture on old brick walls. Pictured: HMP 143 (left) and

HMP 2 31 humidity tra n s m i t t e rs.

The Tenaille von Fe rsen building was completed in 1776.

As an employee of the

Governing Body of Sveabo r g,

Petri Ko i ranen is responsible for

humidity measurements at the

Tenaille von Fe rs e n. The brick s

behind him, dating from 18 t h

c e n t u r y, are badly deteriora t e d.

■

12 148/1998

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Leading-edge brickm a n u f a c t u r i n g

1928 saw the establishment ofGeneral Shale Products Corp.in Johnson City, Te n n e s s e e ,US A. Over the decades, thec o m p a ny has grown and devel-o p e d. In the 19 5 0 s, theyinstalled modern tunnel ki l n sat all their plants, and in the19 8 0 s, with the addition of 3new manufacturing plants, theyraised their annual brick pro-duction capacity by more thanone billion bricks. To d a y, Gen-eral Shale is one of the leadingmanufacturers of exteriorbuilding materials in the US A.The company’s primary focusis the production of more than250 types of face brick for resi-dential and commercial appli-c a t i o n.

General Shale’s 18 produc-tion facilities are strategicallylocated in key distribution areas.Sales are supported by a nation-wide network of distributors inthe USA and Canada. The crea-tion of unique brick sculp-t u r e s for public buildings andresidences is a growing serv i c ea r e a.

Still based in Johnson City,Tennessee, General Shale employsabout 1,500 people. The corpo-

rate office houses the foremostb r i ck museum in America. Bricksof historical significance fromaround the world are on dis-p l a y, including a 10,000 year oldb r i ck from beneath the biblicalcity of Je r i ch o.

Key role of RHm ea s u r e m e n ti n s t r u m e n t s

According to John Brown, Gen-eral Shale has used various hu-midity instruments. “We havet e s ted and installed numeroush u m i d i t y -related devices in ourd rying processes. Most of thesedevices were effective initially,but they soon became difficultto calibrate and were eventual-ly considered unreliable.”

John Brown currently worksas the Manager of ProcessR e s e a r ch company -wide. Hehas been with General Shalesince 1964, when he graduatedfrom No rth Carolina State Uni-versity with a B. S. in CeramicE n g i n e e r i n g. Starting as a pro-duction supervisor in brickm a n u f a c t u r i n g, he became plantmanager in 1971, when he trans-ferred to research & develop-ment.

“Since 1971, I have special-ized in the purchase, applica-

A Vaisala humidity

and tempera t u r e

t ransmitter in the dryer

recirculation sys t e m.

Brick Drying Requires

With facilities strategi-cally located acrossthe US A, GeneralShale Brick is one ofthe largest brick manu-facturers in the coun-t ry. The company pro-duces more than 250types of face brick. AsJohn Brown, Managerof Process Research,e x p l a i n s, “The reasonwe use Va i sala humid-ity measuring productsis simple. They work!We need to measureand control humidityin our drying facilities,and the Va i sala unitsare effective for thispurpose. These unitsare also reasonablyeasy to calibrate andm a i n t a i n. ”

Strong expertise from General Shale Brick

Ri chard KershawRegional Sales ManagerVa i sala BostonM A, US A

13148/1998

placed fans to supply heated lowhumidity air and remove mois-ture laden air.

All sensors, fans and othercomponents are computer con-t r o l l e d. Most of the shrinka g ewater is removed in the predry-er and the remainder of thewater (referred to as pore water)is removed in the final hightemperature dry e r. At the en-trance of the dry e r, the cars ofb r i cks are exposed to a relativehumidity of 30 to 45 per cent.A humidity sensor on the dry e rexhaust fan maintains this levelof humidity by allowing com-puter control to increase or de-crease the amount of heated air

passing through the dryer tomeet load requirements.

Depending on the ambientc o n d i t i o n s, outside air cancause unwanted and destruc-tive d e w p o i n t s, so constant posi-t i v e pressure is maintained inthe dryer and predryer to pre-vent it from being drawn intoe i t h e r. To ensure that all of them e chanical water is removed,the cars of bricks exit the dry e rat 177 to 204 °C (350 to4 00 ° F). This completes thed rying process, and the cars ofb r i cks then enter the kiln forthe firing stage.

tion and development of pro-c e s s e s,” he sa y s, describing hisw o r k. “It is also my responsibil-ity to utilize my training andexperience to analyze and solveprocess problems. In addition,I am a company -wide tech n i c a lresource and also assist in thepresentation of periodic inter-nal seminars to productions u p e rv i s o ry personnel. ”

I d eal for hight e m p e r a t u r e sa p p l i c a t i o n s

The first Va i sala product thatGeneral Shale Brick selectedwas the HMP 13 5 Y. As Mr.Brown explains, the HMP 13 5 Ywas an immediate success inthe company’s drying atmos-phere and became the specifiedhumidity sensor in their pre-d ryer and dry e r s. In most appli-c a t i o n s, a HMP 135Y with amaximum range of 160 ° C( 3 20 ° F) was acceptable.

“ We were pleased when Va i sa l aintroduced the HMP235 hu-midity/dewpoint transmitterbecause of the increase in tem-perature 180 °C (356 ° F) range.Our production superv i s o r sl i ked these units because of theirreliability and ease of calibra-t i o n. The addition of HMI 41electronic calibrator was veryhelpful in plants where severalVa i sala HMP units were used,because they could be calibrat-ed without removing themfrom their installed position.

“ Va i sala’s humidity measur-ing products are reasonablyeasy to calibrate and maintain.We need to measure and con-trol humidity in our drying fa-c i l i t i e s, and these Va i sala unitsare effective for this purpose.

According to Mr. Brown, “Itis not General Shale Brick’ sp o l i cy to specifically endorse,promote or enter into any agree-

ment with any supplier otherthan internally. When anotherb r i ck manufacturer asks foradvice, however, we will and dohelp when we can. We also workwith suppliers to combine theirknowledge with ours and spe-cifically adapt their product toour application. ”

Humidity mea s u r e m e n tin the brick dryingp r o c e s s

At General Shale’s brick manu-facturing plants, conditioningof the green (moisture by dryweight is from 16 to 20 perc e n t) stiffmud extruded bricksbegins as soon as each car ofb r i cks is completely loaded.E a ch car of bricks is moved tothe entrance end of the predry-er (low temperature dryer in t h e21 – 49 °C, i.e. 70 – 120 ° F, range).The recommended relativehumidity of the air at the en-trance end of the predryer is 70to 80 per cent. This allows theb r i cks to dry at a very slow ratei n i t i a l l y, as well as evening outtheir overall body, set, size, (de-pending on the car size, the num-ber of modular bricks rangesfrom 2,688 to 10,240 bricks / c a r )moisture and temperature.

The predrying process condi-tions the bricks and minimizesdifferential shrinkage, which cancause the bricks to crack. Th es h r i n kage can also cause theb r i ck set to become unstableand actually fall off the car.

After initial conditioning,the humidity and pressure sen-sors are utilized to set up anoverall drying curve in thep r e d ry e r. By the time a car ofb r i cks reaches the end of thep r e d ry e r, the relative humidityis approximately 35–50 per cent.The predryer is a facility withfive or six tracks, each 150’ to170’ long with appropriately

Ge n e ral Shale’s automatic brick pa cking sys t e m.

An automatic setting head loads bricks onto the kiln car.

Careful Humidity Contro l

■

14 148/1998

UP M-K y m m e n e ,Finland’s largest foresti n d u s t ry company and

paper manufacturer,relies on a new Va i sa l a

concept to measurethe water content in

the lubrication systemof its paper mach i n e s.This method is basedon the measurement

of a simple and unam-biguous parameter: aw.

S u p p o rting the newmeasurement princi-

ple, Va i sala’s HMP 2 2 8transmitter is designedfor convenient instal-lation through a ball

valve and easy calibra-tion against salt solu-

t i o n s.

P M-Kymmene’s for-est industry tradi-tions date back morethan 100 years. Meas-

u r e d by its turnover, the UP M-Kymmene Group is Europe’slargest forest industry companyand one of the biggest in thew o r l d. Its forest industry opera-tions are organized under sevend i v i s i o n s.

A major paperm a n u f a c t u r e r

UP M-Kymmene’s total paper-m a king capacity is eight mil-lion tons a year. The company ’ s

mills have undergone majorexpansions and moderniza-tions in recent years, and todaythey account for a total ch e m i-cal pulp production capacity oftwo million tons a year. Th eGroup owns 940,000 hectaresof forest in Finland. Annualwood consumption exceeds 20million cubic meters. At theend of 19 97, the UP M-K y m-mene Group had a total of3 3 , 814 employees, including23,200 in Finland.

The UP M-Kymmene mill inTe rv a saari produces high-q u a l-ity sa ck papers, shaded en-velope papers and special indus-trial papers, release and labelpapers for self adhesives, ands e m i -a l kaline pulp (S A P). Th eTe rv a saari mill marked a majormilestone in May 1998, when itproduced its 7 millionth ton ofp a p e r.

A Va i sala HMP228 transmit-ter has been installed in Te rv a-saari’s paper machine to meas-ure the water content of thelubrication system. Mr. HeikkiKataja and Mr. MarkkuSironen handle the preventivemaintenance of the mill’s paperm a chine. Mr. Ka t a j a, who hasoverall responsibility for pre-ventive maintenance, has usedthe HMP228 for more than a

y e a r. As he report s, it hasimproved the quality of main-tenance ever since it was in-stalled in March 19 97.

HMP 2 28 enables on-line moisturem ea s u r e m e n t s

By measuring the moisture inthe oil of a paper machine’s lubri-c a t i o n s y s t e m, mills can signifi-cantly reduce maintenance costsand prolong the machine’s ser-vice life. Va i sala’s new HMP 2 2 8t r a n s m i t t e r, a microprocessor-based instrument for moisturem e a s u r e m e n t, is ideally suitedto measuring the water activityin these lubrication systems.

The operation of the sensor isbased on capacitance ch a n g e sas the thin polymer film ab-sorbs water molecules. Wa t e ractivity (aw) measurement offersseveral advantages over the tra-ditional parts per million (ppm)measurement used in Ka r lF i s cher’s titration.

Flexible mea s u r e m e n tc o n c e p t

The HMP228 transmitter meas-ures water in oil in terms ofwater activity (aw), which can bedetermined as follows: water

Vaisala’s HMP228 transmitter was

installed to measure the water

content in the lubrication system of

Tervasaari’s paper machine in

Ma r ch 19 97.

The paper machine at the Tervasaari mill.

HMP228 moisture and temperature transmitter

Water Content Measurements Ke e pPaper Machines Running Smoothly

U

Lauri Tu o m a a l a, M. S c. (E l. E n g. )Area ManagerSensor System DivisionVa i sala HelsinkiF i n l a n d

15148/1998

Figure 1: Relationship between water content and aw. This figure illustra t e s

Vaisala’s new measurement concept. When the ppm (parts per million) values

are used to measure water content, the type of oil and aging must be taken into

careful account. For example, 200 ppm in one oil can indicate that it is

s a t u rated with water (the water is in a free form); with another type of oil, this

l evel can be far from satura t i o n. Instead of measuring ppm values, Va i s a l a ’ s

concept provides real-time information about the presence of water in the oil

(whether it is old, new, used, cold or hot).

Figure 2. Bearing sealings leak when the machine is being washed.

activity indicates the amountof water in the oil on a scalefrom 0 to 1 aw. On this scale,0 aw indicates that the oil iscompletely water free, while1 aw indicates that the oil isfully sa t u r a t e d. Water occurs infree form as aw is 1.

The most important featuredistinguishing the measure-ment of water activity (aw) fromtraditional measurements ofabsolute water content (inp p m) is the capability to detectthe saturation point rega r d l e s sof the oil type, aging of the oil,additives used, etc. Other ad-vantages of the HMP228 in-clude easy installation througha ball valve and on-line meas-urement capability.

As Mr. Kataja explains, wateris an undesirable substance inthe lubricating system of apaper machine. It causes corro-s i o n, absorbs or consumes ad-ditives in the oil and short e n sbearing life and the service lifeof the entire mach i n e .

HMP 2 28 offers ea s ycalibration and reliablem ea s u r e m e n t s

Karl Fischer’s titration (see Fig.1) is the ‘de facto’ standard formeasuring the water content ofo i l, says Mr. Ka t a j a. “Ev e nthough Karl Fischer’s titrationis a reliable method, we arev e ry pleased with the benefitsoffered by the HMP228 trans-mitter and Va i sala’s new con-c e p t. The instrument is easy tocalibrate against salt solutions,and no reference oils are need-e d.” Water activity is a reliablemeasure of the safety margin tothe saturation point.

“ The amount of water in thelubrication system is one of themain concerns in preventivemaintenance,” Mr. Kataja ex-p l a i n s. “Although there is alwayssome water in the system, ourchallenge is to keep the watercontent at an acceptable level.With the HMP228, this is nowv e ry easy. ”

Components of the oillubrication system

The lubrication system of apaper machine typically con-sists of an oil tank, circulation

pump and separator or purifier.The separator is only able toremove water that is in freef o r m. In addition to the separa-tor or purifier, there is also anair dryer in the reservoir tank toremove humidity from the airin the tanks.

In modern paper mach i n e s,there are usually two separatelubrication systems, one in thewet end and one in the drye n d. Each system containsfrom 10 to 30 cubic meters ofo i l. It is not unusual to removefrom 20 to 40 liters of waterfrom the system every week.The risk is that this moisturewill come into contact with them a chine bearings. Leaks in thebearing sealings, especially whenthe machine is being washed athigh pressure, are the most com-mon reason for the presence ofw a t e r. The oil is changed ap-proximately every seven years.

In paper mach i n e s, the oilabsorbs the water while lubri-cating the bearings and thenreleases it for subsequent col-lection in a reserv o i r. From thestandpoint of the bearings, themain objective is to avoidexposure to oils with a highwater content. This is crucialduring production breaks be-cause the risk of water sa t u r a-tion increases as the oil tempera-ture decreases.

Experience at UPM -Kymmene’s Te r va s a a r im i l l

Citing the following example(F i g. 2), Mr. Kataja demonstratesw hy the Te rv a saari mill uses theHMP228 in all its lubrication sys-t e m s.

As shown in this figure, the‘normal’ aw value for this mod-ern machine is from 0.3 to 0.5.When the bearing sealingscaused a leak in the system, theaw value jumped to approxi-mately 0.9. “The benefits of theHMP228 are clear. It providedan immediate alarm that some-thing had happened. The oilhad become saturated withw a t e r, and it took some timebefore the situation returned ton o r m a l. The point is that wewere able to start troubleshoot-ing immediately,” says Mr.Ka t a j a.

Heikki Kataja (left )

and Ma r k k u

Sironen are

responsible for

p r ev e n t i v e

maintenance of the

paper machine at

the Tervasaari mill.

■

16 148/1998

Water is known by dif-ferent names in differ-

ent states. It can alsobe measured in many

ways and describedwith various terms.

The following art i c l eexplains the behaviorof water vapor in air

and clarifies the termi-nology used to

describe it.

s the saying goes inF i n l a n d, a belovedchild has manyn a m e s. The sa m e

applies to water, includingwater in gaseous form, which isthe source of all life on ourp l a n e t. Most of us have heardof relative humidity and dewpoint temperature, but thereare many other ways to meas-ure the presence of water.P a rtial water vapor pressure,absolute humidity, frost point,mixing ratio, wet bulb tempera-ture and even enthalpy alldescribe the humidity of a ga s.

When the term humidity isu s e d, we usually mean water va-por in a ga s, typically air. Mois-ture, on the other hand, is usedfor liquids and solid materials.The term moisture also appliesto extremely dry ga s e s, whenwater vapor is considered ani m p u r i t y.

Properties of gasm i x t u r e s

A full understanding of the vari-ous terms for humidity andmoisture requires some basicknowledge about the propert i e sof gas mixtures.

In a gas mixture such as air,the total pressure (same as at-mospheric or barometric pres-sure) of the gas is the sum of allthe individual pressures of its

gas components. The atmos-pheric pressure, usually around1000 hPa, is the total of the par-tial gas pressure of nitrogen( ~ 775 hPa), oxygen (~205 hPa) ,water vapor (~10 hPa), argon( ~ 10 hPa), carbon dioxide (~0.4h P a) and a number of othergases with lower partial pres-s u r e s. All gases produce thesame pressure and volume withthe same number of molecules,so the partial pressures also rep-resent the proportion by vol-ume of the various ga s e s. Onthis basis, 21% of the total vol-ume of dry air is oxygen andaround 1% is typically argon.

Water vapor pressurepw [ h Pa, PSI, Pa, mbar,m m H g, inHg, mmH20 ori n H2O]

The air temperature dictates themaximum partial water vaporpressure in air, in other words,the water vapor saturation pres-sure. The ability of water to bein gaseous form is stronglydependent on its temperature(see Figure 1: Water vapor sa t u-ration pressure curv e ) . The high-er the temperature, the higherthe partial pressure of the waterv a p o r. The partial water vaporpressure in the immediate pres-ence of liquid water equals thesaturation pressure at that spe-cific temperature.

At 100 °C, the boiling pointof water, the water vapor pres-sure surpasses normal atmos-pheric pressure. In this light,the boiling point of a liquid isdependent not only on thep hysical properties of the liq-u i d, but also on the surround-ing atmospheric pressure. If theFinnish mountain climber Mr.Ve i kka Gustaffson made him-self a cup of tea on top ofMount Ev e r e s t, the taste wouldprobably leave something to bed e s i r e d. The atmospheric pres-sure at an altitude of 8,800meters is only about one-t h i r dthe sea level pressure, so the teawater would boil at well below70 ° C .

Re l a t i ve humidity RH [%]

Relative humidity is the mostcommonly used humidity unit.‘Relatively’ few people, howev-e r, understand what it reallym e a n s.

The ‘relative’ in relative hu-midity expresses the relation be-tween the amount of water va-por present and the maximumamount that is physically pos-sible at that temperature. Inother words, relative humidity,expressed in per cent, is thep a rtial water vapor pressure inrelation to the saturation pres-s u r e .

Figure 1. Water vapor saturation pressure curve. Figure 2. Dew point of gas at 80 °C and 42% RH.

Relative humidity, dew point, mixing ratio…

The Many Faces of Water Va p o rRelative humidity, dew point, mixing ratio…

The Many Faces of Water Va p o r

0 50 60 70 80 90 100

emperature (° C)

0

200

400

600

800

1000

1200

0 10 20 30 4

T

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60 70 80 90 100

Temperature (° C)

T=80 °CRH = 4 2 %

RH = 10 0 %at 60 °C:Dew point= 60 °C

A

Juhana Häkkä n e n, M. S c. (Te ch. )Product EngineerSensor Systems DivisionVa i sala HelsinkiF i n l a n d

17148/1998

% RH = 100% * (pw / pw s)

w h e r e : pw = partial watervapor pressure

pw s = water vapor’ssaturation pressure

If the maximum amount ofwater vapor has been reach e dand more water is introducedinto the air, an equal amountof water must transform backto liquid or solid form throughc o n d e n sa t i o n. At this point,the air is said to be sa t u r a t e dwith water, and the relative hu-midity is 100%. On the otherend of the scale, when there isno water vapor in the air, therelative humidity is 0% whatev-er the temperature. In otherw o r d s, relative humidity alwayslies between 0 and 10 0 % .

As mentioned above, theability of air to hold water va-por is strongly dependent ontemperature. Th i s, of course,means that relative humidity isalso strongly temperature depend-e n t. Let’s imagine that the out-side temperature on a crisp win-ter day is -14 °C, and the rela-tive humidity is 60%. As thisair enters a building it is heatedto +21 °C, but the amount ofwater remains constant – nowater is removed or added tothe air in normal ventilations y s t e m s. Because of this heat-i n g, the saturation pressure ofthe water vapor rises (i.e. themaximum possible amount ofwater vapor in the air), but thep a rtial pressure of the watervapor is unch a n g e d. In thiscase, the relative humidity willdrop to 5%, which is usuallyconsidered too dry for com-f o rt.

Temperature changes alsoexplain why we can sometimes‘see our breath’ outdoors. Con-sider what happens when westand outside on a cool springm o r n i n g, at +7 °C and 80%RH. As we exhale air at about+ 32 °C and 90% RH, it coolsr a p i d l y, reaching the sa t u r a t i o npoint at around +30 °C. As thecooling continues, excess watervapor condenses into tinywater droplets, which we see assteam or mist.

Dew point temperatureTd [°C or °F]

This brings us to another wide-ly used humidity unit: dewpoint temperature (°C or °F) .Dew point is the temperaturewhere condensation begins, orwhere the relative humiditywould be 100% if the air wasc o o l e d. This is readily apparentfrom the diagram for waterv a p o r, given that dew point isjust a more intelligible way toexpress partial water vapor pres-sure (see Figure 2: Dew point ofgas at 42% RH) .

Even though dew point isexpressed as a temperature, itcorrelates with the amount ofwater vapor in the air, and istherefore not dependent onambient temperature. Dew pointtemperature is always less thanor equal to the actual tempera-ture, with the extremes for nor-mal outdoor air being –30 ° Cand +30 °C. Dryer and wettergases can be found in indus-trial e nv i r o n m e n t s, for example,where dew points between– 100 °C and +100 °C are some-times measured. Th e o r e t i c a l l y,the dew point temperature canbe as low as –273 °C (absolutez e r o), but at a normal atmos-pheric pressure it can never ex-ceed 100 °C. When the dewp o i n t is 100 °C, the air onlycontains water vapor and noother ga s, so the amount ofwater cannot be raised withoutincreasing the density of thev a p o r, and hence the pressure.

The water vapor sa t u r a t i o npressure at different tempera-tures is a known variable, so thedew point can be calculatedfrom the relative humidity andtemperature. Conv e r s e l y, if thedew point and temperature orrelative humidity are kn o w n,the missing variable can be cal-c u l a t e d.

A glass of beer or any colddrink provides a practical exam-ple of dew point. Since the glassconducts heat fairly well, it coolsto almost the same temperatureas the drink. The air surround-ing the glass is then cooled, cre-ating a thin layer of air at near-ly the same temperature as theg l a s s. If the temperature of thedrink is below the dew pointtemperature of the surroundinga i r, the air around the glass willbecome saturated with water

and the excess water will con-dense on the surface of the glass.These small water droplets arecalled dew.

If the temperature of the drinkis above the dew point temper-ature of air, the relative humid-ity of the air surrounding theglass will be higher than theambient humidity, but no vis-ible condensation will occur.

Frost point Tf [°C or °F]

If the dew point temperature isbelow the freezing point, theterm frost point is sometimesu s e d. The water vapor sa t u r a-tion pressure of ice is slightlylower than that of water, whichmust be taken into account whencalculating frost point. Whenfrost actually forms on a sur-face, it always occurs at thefrost point, and not at the dewpoint temperature.

Absolute humidity a [g/m3 or gr/ft3]

Absolute humidity refers to theweight of water in a certain vol-ume of ga s. For example, on atypical summer day (+23°, 55%RH), there are 11.3 grams ofwater vapor per cubic meter.The density of air varies withpressure, so the absolute humid-i t y depends quite strongly onthe gas pressure. In pressurizedp r o c e s s e s, the pressure must beknown in order to calculate ab-solute humidity from the otherhumidity variables.

Because absolute humidityprovides a reliable idea of theamount of water present, it isfairly widely used.

Mixing ratio x [g/kg or gr/lb]

Mixing ratio defines the weightof water in the volume occu-pied by one kilogram of dryga s. In other words, 9.6 gramsof water would have to be vapor-ized into a kilogram of air toobtain the same summer air asdescribed in the previous sec-t i o n. The density of air varieswith pressure, so the mixingratio is also dependent on thepressure of the ga s. In pressur-ized processes the pressuremust be known in order to cal-culate mixing ratio from otherhumidity variables.

Mixing ratio is mainly usedfor calculating water contentwhen the mass flow of air iskn o w n, in ventilation systems,for example.

Wet bulb temperatureTw [°C or °F]

As water evaporates, it con-sumes heat. This cooling effectdepends on the ambient tem-perature and the difference be-tween the water vapor pressureof the ambient air and the sa t u-ration pressure at that tempera-ture. By measuring the coolinge f f e c t, it is therefore possible todetermine the ambient relativeh u m i d i t y. The cooling effect ismeasured with a psych r o m e t e r,an instrument with two ther-m o m e t e r s, one of which is cov-ered by a wet cloth. The read-ing of this thermometer is calledthe wet bulb temperature. We tbulb temperature can also becalculated from the tempera-ture, pressure and relative hu-m i d i t y.

E n t h a l py h [kJ/kg or Btu/lb]

Enthalpy is a unit expressing theenergy content of a ga s. Strictlys p e a ki n g, it should not be in-cluded in this article of humid-ity units. But as water vapor hasa very high specific heat capac-ity and can be present in air inwidely different concentrations,it has a very strong influenceon enthalpy.

Enthalpy represents the amountof energy needed to bring a ga sto its current from a dry gas ata temperature of 0 °C. Energyis consumed to vaporize thew a t e r and raise the temperatureof the humid ga s. Enthalpy ism o s t commonly used whencomparing the heat content ofgases in air conditioning andother systems. ■

18 148/1998

he use of sa t u r a t e dsalt solutions is anaccepted and reli-able method for cali-

brating humidity instruments.M a ny leading laboratories usethis method, which has beengenerally known since the early19 0 0 s. The operating principleis based on the properties ofsalt and water solutions, whichgenerate a known relativehumidity in the air abovet h e m.

Based on these reference v a l u e s, the reading of the humid-ity instrument can then beadjusted and calibrated. Satu-rated salt solutions provide areliable measurement standardas the humidity levels generat-ed by these solutions and theirbehavior at different tempera-tures are well documented andhave been verified by many re-s e a r ch e r s. The Greenspan table( Table 1) is one of the mostw e l l -known references.

Several different salts aresuitable for reference measure-m e n t s, providing a number ofoptions for the user. With highquality instruments, however,no more than two referencepoints are needed to adjust themeasurement over the entirerelative humidity range.

Shortened thermal andhumidity stabilizationt i m e

During the development of theHMK 15, Va i sala’s latest humid-

i t y calibrator based on sa t u r a t e dsalt solutions, the main goalswere to improve the ease of useand reliability of the system. Th es h o rtened thermal and humiditystabilization time of the HMK 15 ,w h i ch is one of the main im-provements in the new design,speeds up calibration andimproves the reliability of ther e s u l t s. By combining an alu-minum chamber and properm e chanical design, the sa l tchamber is optimized for fasttemperature stabilization. Th einner space of the chamber isshaped to promote fast humid-ity stabilization and the genera-tion of a homogenous atmos-phere above the salt solution.

Ready-dosed saltpackages come withcalibration certificates

Other new additions include sa l tp a ckages with calibration cer-tificates from an accredited la-b o r a t o ry. Examples of the sa l tsolutions suitable for the HMK 15calibrator include lithium ch l o-ride LiCl (11% RH), magne-sium chloride MgCl2 ( 3 3 %RH), sodium chloride NaCl( 75% RH) and potassium sul-phate K2SO4 ( 97% RH). Allthese salts are delivered fromthe factory in dry format toavoid any problems that mayoccur with ready-made salt so-l u t i o n s. Dry salts also offer am u ch longer storage life thanr e a d y -mixed salt solutions.

The ready-dosed salt pack-

K08 (EN45001)(ISO/IEC Guide 25)

Easy and ReliableC a l i b ration with theHMK 15 HumidityC a l i b ra t o r

No humidity instru-ment stays accurate onits own. From time totime, the perf o r m a n c e

of these instrumentsmust be ch e cke d

a gainst a reference.When calibration is

done in-house, the useof saturated salt solu-tions as a reference isa proven and afford-

able method. Wi t hVa i sala’s HMK 15

humidity calibratorhumidity calibration is

easy and reliable.

Vaisala’s Measurement Standards Labo ratory at the Vaisala headquarters in

He l s i n k i, Finland, is a FINAS accredited calibration fa c i l i t y. For more

i n f o r m a t i o n, please visit w w w. e u ro pe a n-a c c re d i t a t i o n. o r g

T

Jan Grönblad, M. S c. (E n g. )Product ManagerSensor Systems DivisionVa i sala HelsinkiF i n l a n d

19148/1998

ages are delivered with calibra-tion certificates granted on thebasis of a batch ch e ck. In thisp r o c e s s, a sampling of packa g e sis taken from the batch and thesalts are prepared according tothe user instructions. These sa l tsolutions are then ch e cked atVa i sala Helsinki’s accreditedMeasurement Standards La b o r a-t o ry. The calibration cert i f i c a t everifies that the equilibriumhumidities generated by thesesalt solutions correspond t oGreenspan’s calibration tablewithin the specified accuracy( Table 2). To achieve this accu-r a cy, the HMK 15 instructionmanual includes a guide on howto prepare and store salt solu-t i o n s. Various standards (ASTME 104-85, DIN 50008, JIS Z8806)also include recommendationsand instructions on how to pre-pare salt solutions.

Tr a c eability to aNational Standard

For some applications, traceabil-i t y to a National Standard isn e e d e d. In these cases a humid-ity transmitter like the Va i sa l aHMP233 can be used as thereference in parallel with theactual humidity instrument inthe salt ch a m b e r.

When verifying traceability, thesalts are used only to generatedifferent humidity levels, andthe reference value is read fromthe output/display of the refer-ence instrument. The HMP 2 3 3reference transmitter must then

With Vaisala’s HM K 15 humidity calibra t o r, humidity calibration is easy and reliable.

Te m p . / ° C LiCl / %RH M g C l2 / %RH NaCl / %RH K2S O4 / %RH

0 * 33.7 ±0.3 75.5 ±0.3 98.8 ±1.15 * 33.6 ±0.3 75.7 ±0.3 98.5 ±0.91 0 * 33.5 ±0.2 75.7 ±0.2 98.2 ±0.81 5 * 33.3 ±0.2 75.6 ±0.2 97.9 ±0.62 0 11.3 ±0.3 33.1 ±0.2 75.5 ±0.1 97.6 ±0.52 5 11.3 ±0.3 32.8 ±0.2 75.3 ±0.1 97.3 ±0.53 0 11.3 ±0.2 32.4 ±0.1 75.1 ±0.1 97.0 ±0.43 5 11.3 ±0.2 32.1 ±0.1 74.9 ±0.1 96.7 ±0.44 0 11.2 ±0.2 31.6 ±0.1 74.7 ±0.1 96.4 ±0.44 5 11.2 ±0.2 31.1 ±0.1 74.5 ±0.2 96.1 ±0.45 0 11.1 ±0.2 30.5 ±0.1 74.4 ±0.2 95.8 ±0.5

* The use of an LiCl solution at temperatures below +18 °C is not recommended as its equilibrium humidity can change permanently.1G r e e n s p a n, L.: Journal of Research of the National Bureau of Standards – A Physics and Chemistry Vo l. 81 A, No. 1 January – F e b r u a ry 1977, pp. 89–95

Table 1. Gr e e n s pan’s calibration table1

for generated humidity levels for four commonly used salts over a

t e m p e rature range of 0 to 50 °C. In each column, the numbers on the right indicate Gr e e n s pan’s uncertainty for

the reference humidity of the salt.

20 148/1998

Typical sources of errors in humidity calibration

Temperature difference between the humidity probe and calibrationc h a m b e r

As relative humidity is a very temperature dependent physical parameter, it is impor-tant to have both the calibrator and the humidity probe at the same temperature. At e m p e r a t u re diff e rence of ± 1 °C at + 20 °C between the air in the chamber andthe sensor causes an error of ±3% RH at 50% RH and ±6% RH at 97% RH. To avoidt e m p e r a t u re diff e rences, it is recommended to allow the humidity instrument and cali-brator to stabilize for at least 30 minutes in the same ambient temperature.

The probe should be handled as little as possible to avoid the warming effect ofthe hands. To prevent the salt chamber and other parts of the calibrator from warm-ing up and causing errors in the readings, they should not be held during calibra-t i o n .

Insufficient stabilization time

The response time of thin film polymer sensors is very fast, usually less than 10 sec-onds for the sensor element itself. After the humidity probe is inserted in the calibra-t o r, however, it takes some time before the air around the humidity sensor elementreaches equilibrium with the generated humidity level. A temperature diff e re n c ebetween the humidity probe and calibration chamber increases the stabilization time.The recommended stabilization time for reliable calibration is from 10 to 20 minutes.

O verly narrow range between the calibration points

Multiple calibration points ensure the accuracy of the calibration results over a widehumidity range. If the instrument reading must be adjusted (i.e. if the output re a d i n gis changed to correspond to the re f e rence value), two points are sufficient for a high-quality humidity instrument that is used over a wide humidity range. The first point isused for zero point (offset) adjustment and the second point for span (gain) adjust-ment. A diff e rence of 50% RH or more is recommended between these two points.

Dirty or wet eq u i p m e n t

To avoid contamination, the salts and equipment must be handled carefully and keptabsolutely clean. Even a tiny drop of water on the probe near the sensors can dis-t o rt the re a d i n g s .

Table 2. The specified accuracy of an HM K 15

c a l i b rator delivered with a calibration certificate.

Lithium chloride LiCl ± 1.0% RH + Greenspan’s uncertainty *

Magnesium chloride MgCl2 ± 1.0% RH + Greenspan’s uncertainty *

Sodium chloride NaCl ± 1.4% RH + Greenspan’s uncertainty *

Potassium sulfate K2S O4 ± 1.5% RH + Greenspan’s uncertainty *

* The uncertainty given in Greenspan’s calibration table at the calibration temperature, e.g. the accuracy of LiCl sa l t

at +20 °C is ±(1.0 + 0.3) % RH = ±1.3% RH

be calibrated by a national calibra-tion laboratory (e.g. CET I AT,NIS T, NPL, PT B) to obtain then e c e s sa ry traceability to thenational standard.

Thermometer as ana c c e s s o r y

A thermometer with a calibra-tion certificate is included withthe HMK 15 calibrator. Th epurpose of the thermometer isto measure the temperature ofthe air above the salt solution.The temperature reading isused primarily to select the cor-rect reference humidity valuefrom Greenspan’s table, whichis printed on the calibrator.

In addition, the accuracy ofthe thermometer is sufficientfor ch e cking the temperaturechannel of the humidity instru-m e n t. The thermometer hasbeen calibrated at six pointsand is traceable to the FinnishNational Measurement Stan-dards La b o r a t o ry* for tempera-ture. For more accurate results,the corrections given in the cali-bration certificate or their inter-polated values can be used.

On-site checks possible

In addition to laboratory use,the calibrator is suitable for on-site ch e cks. During transport a-t i o n, the chambers can betightly closed with specially de-signed transit covers that pro-vide a complete seal and pre-vent any leaks of the salt solu-t i o n. The optional transit bagm a kes it easy to transport thec a l i b r a t o r. Th a n ks to the fasttemperature stabilization of thec a l i b r a t o r, the waiting time foro n -site calibration is compara-tively short. ■

* The Finnish National Measurement Standards La b o r i t o ry is part of the Centre for Metrology and Accreditation.

21148/1998

he New Yo r k-b a s e dDayton T. Brown,I n c. (DT B) is a proj-ect management

oriented organization whoseprojects range from brief testsor evaluations to complex sup-p o rt engineering, research anddevelopment programs of manyyears’ duration. The Engineer-ing and Test Division of DTB isa recognized leader in the fieldof engineering serv i c e s. It hasone of the most complete inde-p e n d e n t engineering and test-ing facilities in the easternUnited States.

Engineering services forthe toughest customers

Established in 1952, the Engi-neering and Test Division wasinitially involved in qualityassurance testing of armamentand life support equipment forthe U. S. Navy. Soon the opera-tions of the division expandedinto services in diverse engi-neering disciplines for military,g o v e r n m e n t, industrial andcommercial requirements. Th e s es e rvices include the testing of m e-chanical equipment and soft-ware; reliability, maintainabil-ity and failure analyses; qualityaudits; design and fabricationof test facilities; and tech n i c a ld o c u m e n t a t i o n, among manyo t h e r s.

Today the Engineering and Te s tDivision’s customers includegovernment agencies such as theU. S. Navy, U. S. Army, U. S. AirForce, U. S. Coast Guard, De-p a rtments of Energy andTr a n s p o rt a t i o n, Federal AviationAdministration and NationalAeronautics and Space Ad m i n-i s t r a t i o n, as well as industriale n t e r p r i s e s, many of which areF o rtune 500 companies.

Test chambers needhumidity control

An important part of DT B’ se nvironmental and reliabilitytesting involves test ch a m b e r swhere the tested products aresubjected to different humid-ities and temperatures. Mr. To mZ i m o u l i s, who is in charge ofthe test ch a m b e r s, is the De-p a rtment Supervisor for theDynamic and Climatic System

The DTB Engineering and Te s t

Division operates under the

direction of Mr. C. Ke n n e t h

Mo r r e l l y, Senior Vice President.

H i g h -Quality Engineering Services for the Most Demanding Customers

Va i s a l a ’ s

HMP243 is

used in the

d e m a n d i n g

conditions of

DTB’s test

cha m b e rs.

Dayton T. Brown, Inc. (DT B)specializes in engineering andtesting services for demandingm i l i t a ry and industrial customers.The company uses the Va i sa l aHMP243 in its test chambers inconditions that most humiditytransmitters could not handle.

Dayton T. Brown Inc. Engineering and Test Division

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Steven SantoroRegional Sales ManagerVa i sala BostonM A, US A

T

22 148/1998

The HUMIC AP®

C e l e b rates Its2 5 t h

An n i ve r sa r yWith the launch of the HUMICAP

®‚

25 years ago, Va i sala introduced the world’s firstt h i n -film capacitive humidity sensor. Since then,this breakthrough technology has been constant-ly improved, and Va i sala has continued its pio-neering development in the field of humidity

m e a s u r e m e n t.

Group in the DTB Engineeringand Test Division.

M r. Zimoulis explains the de-manding test conditions: “Werequire a rugged and accuratehumidity transmitter that isresistant to condensation dur-ing rapid temperature transi-tions at high relative humid-i t i e s. A typical test temperaturerange is from -40 to 90 °C (-40to 203 ° F) with relative humidi-ty levels as high as 95% at 71 ° C(160 ° F) . ”

The first Va i sala HMP243 dewpoint transmitters were testedin late 1996, and the first pur-chases were made in early 19 97.

“ The HMP243 transmittersare used to monitor and con-trol the relative humidity invarious test ch a m b e r s. Th eunique design of the transmit-ter with its heated sensor headm a kes it ideal for these applica-t i o n s,” Mr. Zimoulis comments.“ The ability of the HMP243 toaccurately measure relativelyhumidity at temperatures of - 40 ° C ( - 40 ° F) has also been ex-tremely useful. Previously usedsensors were only rated to -5 ° C( 23 ° F), and while in most caseswe do not control RH below10 °C (50 ° F), we are often aske dby customers to record the RHat low temperatures. ”

Another plus is the HMP 2 4 3 ’ sability to operate at reduced pres-sures – as low as 2.7 kPa – and tow i t h s t a n d, without damage, ex-tremely low temperatures, downto -65 °C (-84 ° F) .

“All in all, Va i sala’s HMP 2 4 3transmitter has been exactly the

right product for our applica-t i o n. ”

Unique cross-utilizationof talent

The DTB Engineering and Te s tDivision operates under thedirection of C. Kenneth Morrelly,Senior Vice President. In his view,the division’s biggest asset inthe market is its wide range ofe x p e rts from all fields of engi-n e e r i n g.

“ The unique capability andavailability of DT B’s orga n i z a-tional structure is the cross-u t i-lization of talent. The Engineer-i n g and Test Division offers thev e r satility of an engineeringand technician group that is ex-perienced in structural, hy d r a u-l i c, electronic, instrumentation,d y n a m i c, environmental andother key disciplines. From thistalent pool, the project engi-neers and program managersc r o s s -utilize all the expert i s ethat is required to accomplishan assigned task with the high-est level of capability availablewithin the division. ”

This cross-utilization of per-sonnel also makes the orga n i z a-tion more effective, since alle x p e rts can be involved in anyw o r king project. There is no idletime associated with many spe-cialized areas not having enoughwork to keep their employeesb u s y.

DTB’s environmental chamber with a readout attached to the control pa n e l.

HUMIC AP®

s e n s o rs are the flagship

product of Vaisala’s line of humidity instruments.

■

a i sala’s major R&D in-vestments are reflectedin the continuous ad-vances in its humidity

p r o d u c t s. This work has resulted inm a ny improvements to the HUMI-CA P® s e n s o r, keeping it at the fore-front of humidity measurementand opening up totally new appli-c a tion areas. The repeatability, sta-bility and performance of this sen-sor have been demonstrated inm a ny studies. Several examples ofthe wide-ranging application areasof the HUMICAP are described inthis issue of Va i sala Ne w s. ■

V

22 148/1998

The HUMIC AP®

C e l e b rates Its2 5 t h

An n i ve r sa r yWith the launch of the HUMICAP

®‚

25 years ago, Va i sala introduced the world’s firstt h i n -film capacitive humidity sensor. Since then,this breakthrough technology has been constant-ly improved, and Va i sala has continued its pio-neering development in the field of humidity

m e a s u r e m e n t.

Group in the DTB Engineeringand Test Division.

M r. Zimoulis explains the de-manding test conditions: “Werequire a rugged and accuratehumidity transmitter that isresistant to condensation dur-ing rapid temperature transi-tions at high relative humid-i t i e s. A typical test temperaturerange is from -40 to 90 °C (-40to 203 ° F) with relative humidi-ty levels as high as 95% at 71 ° C(160 ° F) . ”

The first Va i sala HMP243 dewpoint transmitters were testedin late 1996, and the first pur-chases were made in early 19 97.

“ The HMP243 transmittersare used to monitor and con-trol the relative humidity invarious test ch a m b e r s. Th eunique design of the transmit-ter with its heated sensor headm a kes it ideal for these applica-t i o n s,” Mr. Zimoulis comments.“ The ability of the HMP243 toaccurately measure relativelyhumidity at temperatures of - 40 ° C ( - 40 ° F) has also been ex-tremely useful. Previously usedsensors were only rated to -5 ° C( 23 ° F), and while in most caseswe do not control RH below10 °C (50 ° F), we are often aske dby customers to record the RHat low temperatures. ”

Another plus is the HMP 2 4 3 ’ sability to operate at reduced pres-sures – as low as 2.7 kPa – and tow i t h s t a n d, without damage, ex-tremely low temperatures, downto -65 °C (-84 ° F) .

“All in all, Va i sala’s HMP 2 4 3transmitter has been exactly the

right product for our applica-t i o n. ”

Unique cross-utilizationof talent

The DTB Engineering and Te s tDivision operates under thedirection of C. Kenneth Morrelly,Senior Vice President. In his view,the division’s biggest asset inthe market is its wide range ofe x p e rts from all fields of engi-n e e r i n g.

“ The unique capability andavailability of DT B’s orga n i z a-tional structure is the cross-u t i-lization of talent. The Engineer-i n g and Test Division offers thev e r satility of an engineeringand technician group that is ex-perienced in structural, hy d r a u-l i c, electronic, instrumentation,d y n a m i c, environmental andother key disciplines. From thistalent pool, the project engi-neers and program managersc r o s s -utilize all the expert i s ethat is required to accomplishan assigned task with the high-est level of capability availablewithin the division. ”

This cross-utilization of per-sonnel also makes the orga n i z a-tion more effective, since alle x p e rts can be involved in anyw o r king project. There is no idletime associated with many spe-cialized areas not having enoughwork to keep their employeesb u s y.

DTB’s environmental chamber with a readout attached to the control pa n e l.

HUMIC AP®

s e n s o rs are the flagship

product of Vaisala’s line of humidity instruments.

■

a i sala’s major R&D in-vestments are reflectedin the continuous ad-vances in its humidity

p r o d u c t s. This work has resulted inm a ny improvements to the HUMI-CA P® s e n s o r, keeping it at the fore-front of humidity measurementand opening up totally new appli-c a tion areas. The repeatability, sta-bility and performance of this sen-sor have been demonstrated inm a ny studies. Several examples ofthe wide-ranging application areasof the HUMICAP are described inthis issue of Va i sala Ne w s. ■

V

23148/1998

Bill Ri ch a r d sRegional Sales Manager Sensor Systems DivisionVa i sala Boston M A, US A

elative humidity hasan effect on theoperation of ma-ch i n e ry and equip-

m e n t. Electrical equipment, forexample, is sensitive to mois-ture. In several industries, env i-ronmental chambers are usedto test the impact of moistureon equipment perf o r m a n c e .Relative humidity measure-ments play a critical role in thisw o r k.

Three years ago, Brian Gristmoved from Hewlett Packa r dR o s e l a n d, California, to HewlettP a ckard Corv a l l i s, Oregon. Hebrought with him years of ex-perience with relative humiditymeasurements in env i r o n m e n-tal test ch a m b e r s. As an env i-ronmental test tech n i c i a n, Mr.Grist is responsible for trainingpeople to maintain equipmentand to run tests on new andexisting products. He also man-ages outsourcing of variousf u n c t i o n s. As he explains, com-munication with vendors hasincreasingly replaced his directh a n d s -on technical work. Hel i kens his position to a stage-hand who is behind the scenesm a king all of the lighting andprops appear and work asplanned so that the actors canconcentrate on their part s.

m a t ches the stability and du-rability that Va i sala offers. ”

Consistent with HewlettP a ckard’s outsourcing policy,the installation of the Va i sa l asensors in the Corvallis env i-ronmental chambers was doneby a local controls contractorselected by Mr. Grist. Mainte-nance and calibration serv i c e sare also handled by a local ven-dor who uses Va i sala’s HMK 41,±1% accurate, one-p o i n t, in-s i t u, electronic calibrator forNIST (National Institute of

Mr. Brian Grist is an environmental test technician at

Hewlett Pa ckard in Co r v a l l i s, Oregon.

Hewlett Packard manufactures pens for desk jets and laptop computers attheir facility in Corv a l l i s, Oregon. Brian Grist, an environmental test tech-n i c i a n, has years of experience with relative humidity measurements andVa i sala’s humidity instruments, which are used in Hewlett Packard’s env i-ronmental ch a m b e r s. As Mr. Grist explains, this is a demanding producte nvironment for high-p e rformance instruments. “Based on our experi-e n c e s, we have not found anything that matches the stability and durabil-ity that Va i sala offers. ”

High marks for stabilityand durability

M r. Grist first came acrossVa i sala when more demandingtest conditions were adopted atthe HP Roseland facility. Atthat time, he began looking forsomething to replace the wetb u l b / d ry bulb sensors in theire nvironmental ch a m b e r s. Afterevaluating competing prod-u c t s, he was convinced that hewould have to lower his perf o r-mance expectations. These sen-sors could do the job better thanwet bulb/dry bulb devices, butnot well enough. “The reliabil-ity was just not there. Once wetested the Va i sala sensors, how-e v e r, we found a solution toour problem. None of theother products could matcht h e m,” he comments.

After moving to the Corv a l l i ssite, Mr. Grist applied his earli-er experiences, replacing all ofthe wet bulb/dry bulb and com-peting electronic sensors in theire nvironmental test ch a m b e r swith Va i sala’s HMM30C, whichwas designed for high tempera-tures and high-p e rf o r m a n c ee nvironmental ch a m b e r s. “Wehave made a full commitmentto Va i sa l a,” says Mr. Grist. “Wehave not found anything that

O ver and Ab ovePerformance for Env i ro n m e n ta lC h a m b e r s

Standards and Te ch n o l o g y )traceable calibrations.

Po s i t i ve experiences

When asked about Va i sa l a ’ ss e rvice, maintenance, and sup-p o rt Mr. Grist replied, “No t h-ing related to Va i sala has everput me in a crisis situation. Sincenothing has failed, I have nothad to use their serv i c e s. That iswhat I like about Va i sala – nos u r p r i s e s. It has been a verypositive relationship. ” ■

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24 148/1998

In Denmark, all me-teorological information

and databases arestored in the Danish

M e t e o r o l o g i c a lInstitute’s supercom-p u t e r s. To keep these

computers operative atall times, specially

ventilated rooms andstrict compliance withhumidity and tempera-

ture limits are essen-t i a l. DMI relies on

Va i sala instruments toensure optimal condi-tions in its computerr o o m s. Va i sala trans-mitters are also used

to ch e ck the sensors inits observation net-

w o r k.

he Danish Meteoro-logical Institute (DMI)is the nerve center ofthe Meteorological

I n s t itute, the Aeronautical Me-t e o r o l o g i c a l S e rvice for civilaviation and the Danish De-fence We a t h e r S e rvice. The data-bases of all three are stored inthe DMI’s NEC S X 4 /16 super-c o m p u t e r s, which require aspecially ventilated roomwhere the temperature must bekept between 16 – 18 °C and thehumidity between 55–70 perc e n t.

Keeping computers cool

Software Engineer Klavs AllerslevJensen works in the Te ch n i c a lDivision of DMI’s Observ at i o nD e p a rt m e n t. He joined the i n s t i-tute staff in 1976, and since thenM r. Jensen has accumulated sev-eral years of experience in thefield with Va i sala products.

M r. Jensen explains the de-mands that supercomputersplace on air conditioning sys-t e m s : “ We use NEC SX4/16s u p e r c o m p u t e r s, which requirea specific temperature and hu-midity to work properly. This isw hy we use a modern comput-

erized control system to moni-t or the cooling system in ourcomputer room. ”

The DMI control system in-cludes four Va i sala HMD 5 0transmitters and one QLI50data collector. Both are con-nected to a PC, which collectsand displays the data. Sup-p o rted by the La b V IEW func-t i o n, the presentation system isprogrammed by DMI’s staff.

Va i sala’s duct-m o u n t e dHMD50 transmitters are de-signed for use in air condition-ing systems. They combineexcellent stability with easyinstallation and reliable opera-t i o n. In addition, the transmit-ters are fitted with the inter-changeable IN T ER CA P® s e n s o r,so no adjustments are needed ifthe sensor is ch a n g e d. The in-struments were installed inMay 19 97.

According to Mr. Je n s e n,quality is their first priority whenp u r chasing new instruments.He comments: “So far, the com-puter department has been verysatisfied with our Va i sala instru-m e n t s. The system has alreadyprovided an early warning of acooler breakdown. We ch o s eVa i sala’s sensors because they

are easy to install and maintain.Their low cost was an anothera d v a n t a g e . ”

I d eal for on-sitec h ecking and calibration

“Our Observation Depart m e n tuses Va i sala instruments toch e ck and calibrate the sensorsin our weather stations,” com-ments Mr. Je n s e n. “The HMP 2 3 3humidity and temperature trans-m i t t e r, for example, is utilizedin the calibration of our otherhumidity sensors, and we usethe HM 31 and HM34 for on-site ch e cking of the humidityand temperature sensors inDMI’s weather stations.

The pressure sensors in DMI ’ so b s e rvation network are ch e cke dand calibrated against Va i sa l as e n s o r s, using the PTB220 ba-rometer as a travelling standard.

According to Klavs AllerslevJe n s e n, the Va i sala instrumentswere chosen primarily becauseof their ease-o f -use. “The qual-ity of the sensors is generallyh i g h, and the PTB220 barom-eter is particularly well suited foruse as a traveling standard. ”

Safeguarding the databases of the Danish Meteorological Institute

C l i m a t e -C o n t rol fo rS u p e rc o m p u t e r s

Klavs Allers l ev Jensen works as a

So ftware Engineer for the Da n i s h

Meteorological In s t i t u t e .

Vaisala’s duct-mounted HMD50 tra n s m i t t e rs are designed for use in air conditioning sys t e m s. They are

ideal for measuring the humidity in computer rooms.

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

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25148/1998

ven in today’s world,fingerprints are stillused extensively i ncriminal investiga-

t i o n s. High t e ch has ga i n e dground here, too, in the f o r mof the cy a n o a c rylate process,w h i ch makes it p o s s i b l e to liftfingerprints from objects withn o n -absorbent surf a c e s. Th eprocess is especially usefulwhen the prints are old or thes u rface is sticky or porous.

C y a n o a c rylate vapor devicesare the specialty of L.E. Frank& Co. GmbH, which has beenmanufacturing them since 19 9 2.The company’s main custom-ers are police departments andtheir criminal inv e s t i ga t i o nu n i t s.

Polymerization revea l sf i n g e r p r i n t s

C y a n o a c rylate is a viscous ad-h esive similar to super glue.

Sherlock Holmes Would Be Impre s s e dSherlock Holmes Would Be Impre s s e d

Fingerprints are diffi-cult to lift fromporous or sticky

o b j e c t s. The cy a n o-a c rylate vapor process,w h i ch can even revealold prints, is one solu-

tion to this problem.Accurate humidity

control plays a crucialrole in the process,w h i ch offers many

advantages over con-ventional methods.

Since 1996, L. E.Frank & Co. GmbH

has used Va i sa l ainstruments in theircy a n o a c rylate vapor

d e v i c e s. Mr. SiegfriedB i n d e r, Director of the

c o m p a ny, gives highm a r ks to the stability

and ease of use ofVa i sala’s HUMI T T ER

50U and HMD 4 0 U.

W h e n exposed to water vapor,the water in the adhesive evapo-r a t e s c a u sing polymerization.F i n g e r p r i n t s have a high waterc o n t e n t, so the polymerizationoccurs to a greater degree onthe characteristic ridges usedfor identification.

During the cy a n o a c rylate va-porizing process, the object tobe fingerprinted – such as a cof-fee cup – is placed in a cabinetmounted on a stainless steelr a ck. About 20 drops of cy a n o-a c rylate are added to the vapor-izer bowl in the device, and thehumidifying unit is switch e do n. When the relative humid-ity reaches 80% RH, the vapor-izer is activated.

As the cy a n o a c rylate vapor-i z e s, it polymerizes on the finger-

p r i n t s. The polymerized cy a n o-a c rylate is then colored with achemical agent such as gentianv i o l e t. This make s the fingerprintstand out from the backg r o u n d,so it can be photographed.

The amount of water in fin-gerprints can vary considerably.Over time, there is a gradual re-duction in the water content, andheat and sunlight tend to a c c e l-erate the process. This effect, h o w-e v e r, can be reversed to some e x-tent by exposing the fingerprintsto water vapor.

Careful humiditymonitoring is crucial

The success of the cy a n o a c ry-late vapor process depends onthe RH in the cabinet, so care-

Siegfried Binder is Director of L. E. Frank & Co. GmbH, which has been

producing cyanoacrylate vapor devices since 19 9 2 .

Lifting fingerprints from difficult surfaces

E

Siegfried Sch m i dSales EngineerSensor Systems DivisionVa i sala Stuttga rtG e r m a ny

26 148/1998

S h i g e ki ShimizuTe chnical ConsultantVa i sala To ky oJ a p a n

The relative humidity in the vaporization cabinet is raised to

80 per cent. When the cyanoacrylate polymerizes, it rev e a l s

the fingerprints on the coffee cup.

ful humidity monitoring is cru-c i a l. Mr. Siegfried Binder,Director of the Stuttga rt -b a s e dL . E. Frank & Co. GmbH, con-tacted Va i sala in 1996 to discussh u m i di t y measurement instru-ments for their application.After a short series of tests, Mr.Binder selected the HUMI T-T ER 50U and HMD40U trans-mitters for their cabinets.

“ The sensor head of theHMD40U was too long for oura p p l i c a t i o n, but we are expert sin plastics treatment, so short-ening the length was not a prob-

le m,” he comments. The Va i-sala instruments were selectedbased on their excellent stabil-ity and ease of maintenance.“ Th e stable interch a n g e a b l eIN T ERCA P® sensor in the Va i-sala transmitters makes our l i v e sm u ch easier in the long run –and the same is true for our cus-t o m e r s. The instruments workfor years without any adjust-ment or service, and this, ofcourse, translates into lower op-erating costs. ”

The To kyo NationalR e s e a r ch Institute of

Cultural Properties hasu n d e rt a ken a long-t e r mproject to monitor thee nvironment in Nara’s

Todaiji Temple. The aimis to determine how

weather conditions affectthe 8th century bronze

lanterns and the statue ofthe Great Buddha in thetemple. Va i sala’s instru-ments were selected forhumidity and tempera-

ture measurement.

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26 148/1998

S h i g e ki ShimizuTe chnical ConsultantVa i sala To ky oJ a p a n

The relative humidity in the vaporization cabinet is raised to

80 per cent. When the cyanoacrylate polymerizes, it rev e a l s

the fingerprints on the coffee cup.

ful humidity monitoring is cru-c i a l. Mr. Siegfried Binder,Director of the Stuttga rt -b a s e dL . E. Frank & Co. GmbH, con-tacted Va i sala in 1996 to discussh u m i di t y measurement instru-ments for their application.After a short series of tests, Mr.Binder selected the HUMI T-T ER 50U and HMD40U trans-mitters for their cabinets.

“ The sensor head of theHMD40U was too long for oura p p l i c a t i o n, but we are expert sin plastics treatment, so short-ening the length was not a prob-

le m,” he comments. The Va i-sala instruments were selectedbased on their excellent stabil-ity and ease of maintenance.“ Th e stable interch a n g e a b l eIN T ERCA P® sensor in the Va i-sala transmitters makes our l i v e sm u ch easier in the long run –and the same is true for our cus-t o m e r s. The instruments workfor years without any adjust-ment or service, and this, ofcourse, translates into lower op-erating costs. ”

The To kyo NationalR e s e a r ch Institute of

Cultural Properties hasu n d e rt a ken a long-t e r mproject to monitor thee nvironment in Nara’s

Todaiji Temple. The aimis to determine how

weather conditions affectthe 8th century bronze

lanterns and the statue ofthe Great Buddha in thetemple. Va i sala’s instru-ments were selected forhumidity and tempera-

ture measurement.

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27148/1998

ince November 19 9 5 ,the To kyo NationalR e s e a r ch Institute ofCultural Propert i e s

has conducted long-term fieldo b s e rvations on the physical con-dition of the bronze lanterns inthe Todaiji Temple in Nara,J a p a n. These lanterns were m a d ein the 8th century, and later de-signated as one of Japan’s na-tional treasures. This year, ther e s e a r ch institute launch e danother research program tostudy the corrosion of the GreatBuddha statue in the temple.

Field observations are madeon wind direction, wind speed,atmospheric temperature, rela- The observation system in front of the Todaiji Temple in Na ra, Ja pa n.

The world’s largest bronze statue of the Great Buddha.

Lo n g -Te r mProject toMonitor theConditions inthe To d a i j iTe m p l e

tive humidity, rain acidity,chemical substances containedin rainwater and air pollutants.The effects of different weatherconditions on the Great Bud-dha statue and the temple canbe studied on the basis of theseo b s e rv a t i o n s.

As part of the env i r o n m e n t a lmonitoring program, the insti-tute measures outdoor humid-ity and temperature with anHMP45A probe and indoor con-ditions with an HMW60Y trans-m i t t e r. The HMW60Y trans-mitters have been installed atfour observation points on thecolumns beside the statue.

Preserving Japan’s national treasures

S

28 148/1998

ecent years haveseen record econom-i c growth in China.Despite the financial

problems currently affectingthe other countries in ther e g i o n, the Chinese are largelyoptimistic about the future.

Va i sala’s Representative Officein Beijing has been serving theChinese market since 19 9 4 .To d a y, the office has a staff ofs e v e n. Their cooperation withlocal customers has been very re-w a r d i n g, and new projects arebeing planned and studied allthe time.

“ With the steady growth andincreasing demand for quality,we believe that there is a good

future for Va i sala’s products inChina’s industrial sector,” notesM r. Knut Saxén, Va i sala’s ChiefRepresentative in the country.

Strong presence in China

M r. Saxén is in charge of theRepresentative Office and allm a r keting activities in China.M r. Steven Ding and Mr. JussiAnnunen work as Sales Repre-sentatives for industrial cus-t o m e r s. Sales of Va i sala’s trans-mitters for industrial applica-tions have seen sharp growth inthe past few years.

“In China, good relation-ships with customers requirefrequent communication and a

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Introducing Vaisala’s sales team for industrial applications in China

(from the left): Knut Sa x é n, Jussi Annunen and Steven Ding.

Ad va n c e denvironmental resea r c hp r o g r a m

Commissioned by the To ky oNational Research Institute ofCultural Propert i e s, Wind Engi-neering Institute Co., Ltd. is re-sponsible for the developmentand management of the obser-vation system used in the re-s e a r ch program. This engineer-ing company has a strong repu-tation for its expert develop-m e n t, analysis and operation ofe nvironmental measurements y s t e m s.

The observation system con-tinuously transmits data via theInternet to the server for subse-quent analysis. This makes itpossible to display various real-time measurements at differento b s e rvation points on remotem o n i t o r s.

The system is also used atother cultural heritage sites,including the great statue ofBuddha at Ka m a ku r a. Manyother sites in Japan could ben-efit from similar observ a t i o n s.E nvironmental measurementsand analysis are essential tomaintain and protect impor-tant objects and sites of cultur-al value, so they can be enjoyedfor as long as possible.

8th Century To d a i j iTemple in Japan’sAncient Capital of Nara

N a r a, Japan’s ancient capital

before Kyoto, is home to many

old temples. The Todaiji Te m p l e ,

for example, which was built in

734 by Emperor Shomu, is the

w o rld’s largest wooden building.

Its name means ‘Great Eastern

Temple’. Twice burn ed and re-

b u i l t, the current wooden struc-

ture dates from 1709. Th e

w o rld’s largest bronze statue of

the Great Buddha is housed in

the Todaiji Te m p l e .

Vaisala’s HMW60Y humidity and

t e m p e rature instrument installed on

a column inside the Todaiji Te m p l e .

Va i sala’s Formula fo r

Success in China

Industrial applications gaining ground

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28 148/1998

ecent years haveseen record econom-i c growth in China.Despite the financial

problems currently affectingthe other countries in ther e g i o n, the Chinese are largelyoptimistic about the future.

Va i sala’s Representative Officein Beijing has been serving theChinese market since 19 9 4 .To d a y, the office has a staff ofs e v e n. Their cooperation withlocal customers has been very re-w a r d i n g, and new projects arebeing planned and studied allthe time.

“ With the steady growth andincreasing demand for quality,we believe that there is a good

future for Va i sala’s products inChina’s industrial sector,” notesM r. Knut Saxén, Va i sala’s ChiefRepresentative in the country.

Strong presence in China

M r. Saxén is in charge of theRepresentative Office and allm a r keting activities in China.M r. Steven Ding and Mr. JussiAnnunen work as Sales Repre-sentatives for industrial cus-t o m e r s. Sales of Va i sala’s trans-mitters for industrial applica-tions have seen sharp growth inthe past few years.

“In China, good relation-ships with customers requirefrequent communication and a

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Introducing Vaisala’s sales team for industrial applications in China

(from the left): Knut Sa x é n, Jussi Annunen and Steven Ding.

Ad va n c e denvironmental resea r c hp r o g r a m

Commissioned by the To ky oNational Research Institute ofCultural Propert i e s, Wind Engi-neering Institute Co., Ltd. is re-sponsible for the developmentand management of the obser-vation system used in the re-s e a r ch program. This engineer-ing company has a strong repu-tation for its expert develop-m e n t, analysis and operation ofe nvironmental measurements y s t e m s.

The observation system con-tinuously transmits data via theInternet to the server for subse-quent analysis. This makes itpossible to display various real-time measurements at differento b s e rvation points on remotem o n i t o r s.

The system is also used atother cultural heritage sites,including the great statue ofBuddha at Ka m a ku r a. Manyother sites in Japan could ben-efit from similar observ a t i o n s.E nvironmental measurementsand analysis are essential tomaintain and protect impor-tant objects and sites of cultur-al value, so they can be enjoyedfor as long as possible.

8th Century To d a i j iTemple in Japan’sAncient Capital of Nara

N a r a, Japan’s ancient capital

before Kyoto, is home to many

old temples. The Todaiji Te m p l e ,

for example, which was built in

734 by Emperor Shomu, is the

w o rld’s largest wooden building.

Its name means ‘Great Eastern

Temple’. Twice burn ed and re-

b u i l t, the current wooden struc-

ture dates from 1709. Th e

w o rld’s largest bronze statue of

the Great Buddha is housed in

the Todaiji Te m p l e .

Vaisala’s HMW60Y humidity and

t e m p e rature instrument installed on

a column inside the Todaiji Te m p l e .

Va i sala’s Formula fo r

Success in China

Industrial applications gaining ground

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29148/1998

strong local presence,” com-ments Mr. Saxén, “Improvingcustomer relationships was oneof the most important reasonsbehind the establishment ofVa i sala’s office in Beijing. Look-ing to the future, the coopera-tion between us and our cus-tomers is sure to intensify.

“ We are the only foreign sup-plier that customers can con-tact directly in China, whetherthey want to buy a new instru-ment or calibrate a probe thatwas purchased earlier. This is oneof our main strengths in theChinese marke t. Our local pres-ence makes it easier for custom-ers to communicate with us,w hi ch is something they greatlya p p r e c i a t e . ”

By the year 2000, China willprobably be the world’s largestconstruction site. The popula-tion of the country is now 1. 2b i l l i o n. Th o u sands of shoppingc e n t e r s, bridges, roads and air-p o rts are slated for construc-t i o n, and Va i sala tech n o l o g yhas applications in all thesep r o j e c t s.

Ma r ket potential fornew technology

At the moment, Va i sala is thelargest foreign company in theChinese humidity instrumentm a r ke t. “So far, we have main-

ly concentrated on high endp r o d u c t s. Chinese customers arev e ry aware of the latest tech-n o l o g y,” says Mr. Saxén.

Examples of local end usersof Va i sala’s industrial productsinclude power stations, anti-epidemic stations, various tele-communication companies andm i l i t a ry customers. “To d a y, hu-midity measurement is ourmain business segment in China.In 1998, we expect to see par-ticularly rapid growth in theH VAC business. In part i c u l a r,w a l l -mounted HMW40Y trans-m i t t e r s, which are designed forair conditioning systems, havegenerated a lot of interest inC h i n a. We also have high expec-tations for carbon dioxide meas-u r e m e n t, which is a new appli-cation area. We have some in-teresting OEM sales prospects.Transmitters and portable metersfor industrial applications havealways sold well. Va i sala has av e ry strong foothold in Chinain these applications,” explainsM r. Annunen.

G r owing need fora d vanced mea s u r e m e n ti n s t r u m e n t a t i o n

As Mr. Ding notes, “Va i sala isbuilding a reputation in Chinaas a reliable world-leading sup-plier of accurate humidity andtemperature instruments forChinese industry. Customerswho need extremely precisemeasurements in these fieldshave shown growing interest inour sensors and instruments. ”

For industrial sa l e s, Va i sa l a ’ sBeijing Office is using local dis-t r i b u t o r s, and these part n e r-ships have been very success-f u l. Va i sala deals with sixChinese distributors: BeijingLaisen Electronic Co. (inB e i j i n g), Instrimpex Innova (inB e i j i n g), Zhuhai Deli Instru-

mentation Co. Ltd. (in Zhuhai,Guangdong Province), JanapoMagnetoelectronic Co. Ltd. (inN a n j i n g, Jiangsu Province),Henan Relations ElectronicsC o. Ltd. (in Zhengzhou, HenanProvince), and Euro Te ch (F a rE a s t) Ltd. (in Hong Kong). Toprovide even better and fasters e rvice for its distributors and cus-to m e r s, Va i sala opened a bond-e d warehouse for industrial meas-urement products in Hong Kongin 19 97.

“China is a large region with29 provinces or special admin-istration areas. There are 56 dif-ferent ‘nationalities’ in China,and an untold number ofdialects of Chinese are spoke n.This is why we need an exten-sive local distributor networkin this culture,” comments Mr.D i n g.

“ To help coordinate our mar-keting activities, we provide tech-n i c a l, training, sales and mar-keting support for our distribu-t o r s. We also conduct marke tr e s e a r ch to find new applica-tions for Va i sala products. ”

Successful customers e r v i c e

“It is essential to inform cus-tomers about our new productsand advanced tech n o l o g y. Weoften arrange technical semi-nars and training sessions forcore customer groups to tellthem about Va i sala’s latest prod-u c t s,” notes Mr. Annunen.

Va i sala makes every effort toensure that end users realizethe full potential of their state-o f -t h e -a rt equipment. For thisre a s o n, training sessions and prod-uct seminars are an integral p a rtof Va i sala’s product program.

As customers, the Chineseappreciate high quality andcompetitive prices first andf o r e m o s t, as well as mainte-nance and training serv i c e s.

“ To be a foreign supplier ofhigh technology products forthe Chinese market is a ch a l-lenge in itself. Our biggest con-cern is how to best serve ourChinese customers and meetthe demands of this rapidlygrowing economy,” says Mr.S a x é n.

Doing business inChina requires exten-sive knowledge of thec o u n t ry and its cul-ture. Va i sala’s humid-ity and temperatureinstruments havegained a significantm a r ket share inChina’s growingindustrial sector. Th eVa i sala name and thec o m p a ny’s high-q u a l-ity products are widelyknown among expert sin humidity and tem-perature measurementand in the air-c o n d i-tioning industry.

Vaisala’s local agent Ja n a p o

Magnetoelectronic Co. Ltd. ( f r o m

Na n j i n g, Jiangsu Province) in the

Miconex-98, Instrumentation and

Control Te chnology Exhibition in

May in Be i j i n g.

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30 148/1998

he current vogue forlarge open plan officeshas created a needfor many other small-

e r rooms for activities such asm e e ti n g s, briefings, appraisa l s,training sessions, etc. Th e s eareas are notoriously difficultto ventilate effectively becauseof their random pattern ofo c c u p a n cy. The time that theroom is occupied and the num-ber of occupants can vary sig-n i f i c a n t l y. How then can wedesign a ventilation system tocope with fluctuating demand?

A simple solution... andone that is even better

One simple method is to relyon a manual on/off switch anda speed control to alter the ven-tilation rate. The problem withs u ch systems is the difficulty ofm a t ching the fan speed withthe conditions and the numberof occupants. These systems,m o r e o v e r, are often left run-ning in an empty room. Th eresult is usually one of twoextremes: unhealthy stuffy con-ditions or too much ventila-t i o n, which is a waste of expen-sively heated or cooled air.

The best solution is to fit aventilation control system thatwill turn itself on and off andautomatically adjust the speedto match the level of occupan-cy. Efficient fan and motorcombinations are import a n t,but it is much more sensibleand effective to switch off thefan or reduce the ventilationrate to match demand. Tu r n i n gthe fan down to half speed, forexample, can cut the motor’spower consumption by up to87 per cent. Add to this the sa v-ings that result from heating orcooling half the amount ofm a ke -up air, and the results canbe staggering.

NuAire’s Smart Squrbos y s t e m

NuAire’s Smart Squrbo demandventilation system incorporatesa temperature sensor, an occu-p a n cy sensor and Va i sa l a ’ sGMD20 carbon dioxide trans-mi t t e r. All these sensors are usedto determine the level of venti-lation necessa ry to keep the airf r e s h.

Va i sala carbon dioxide trans-mitters were selected because oftheir stability and long life.¥

M i ke FussellTe chnical DirectorNuAire Ltd.C a e r p h i l l yUnited Ki n g d o m

A random pattern ofo c c u p a n cy makes ven-tilation more difficult:

the control systemmust be able to detect

when ventilation isneeded and to whate x t e n t. To ensure a

c o s t -effective supplyof fresh air, NuAire

fitted its Smart Squrbosystem with Va i sa l a ’ s

CA RBOCA P®

c a r b o ndioxide transmitters.

NuAire’s new Smart Sq u r bo sys t e m

o f f e rs many fully automatic supply

and extract options for ventilating

smaller rooms.

When the air starts

to get stuffy,

Vaisala’s GM20

c a r bon diox i d e

t ransmitter and

o c c u pancy sensor

alert the ventilation

s ys t e m.

High Indoor Air Quality with Minimum Energy CostsHigh Indoor Air Quality with Minimum Energy Costs

Practical application of demand ventilation

T

31148/1998

In the Huurre Ski Tunnel in Finland,optimal conditions are always guaran-

t e e d. Va i sala transmitters play an impor-tant role at this indoor ski track, continu-ously measuring the prevailing humidity,

temperature and carbon dioxide levels.

he Vuokatti Ski Tr a i n-ing Center is locatedin central Finland.S kiers from all over

the world come here to train –even in the summer time. Th emain attraction is the 1.2 kmS ki Tu n n e l, which has a 2.4 kmnatural snow surface ski track.With curving trails and hills, theconditions are similar to natu-ral outdoor ski trails in every re-s p e c t.

Winter conditionsg u a r a n t e e d

The winter weather conditionsin the tunnel are optimal –there is snow and fresh air, butit is not too cold. Because theconditions are stable, weather-related risks and inconv e n-iences are not a factor. Anadvanced ventilation systemprovides humidity control andgood air quality. Humidity,temperature and carbon diox-ide levels are measured with

The NuAire Group produces

one of the world’s widest ranges

of ventilation fans and eq u i p-

m e n t, from domestic bathroom

and toilet extract fans to large

c o m m e r c i a l / i n d u s t rial units. Th e

company is also a mark e t

l eader in condensation control

equipment for public housing,

and has dev e l o p ed an industry

l eading range of ventilation con-

trols for the commercial sec t o r.

NuAire currently has customers

in over 25 countries worl d w i d e .

Lo c a t ed in Caerphilly, South

Wa l e s, United Kingdom, NuAire

has about 300 employees.

Hanne Österberg, BB A, B. S c. (C o m p. )M a r keting AssistantSensor Systems DivisionVa i sala HelsinkiF i n l a n d

N e ve r -Ending Wi n t e rStability minimizes the need forcalibration and maintenance,helping to reduce the total op-erating costs of the system.

The fan action is directly con-trolled by the sensors. When theo c c u p a n cy sensor detects peo-ple in the room and the carbondioxide level starts rising, thefan switches on, supplying theright amount of fresh air to ther o o m. This prevents the roomsfrom becoming stuffy and pro-vides healthier conditions forthe occupants. Since the fan isused only when needed, thiseliminates excess energy con-s u m p t i o n.

NuAire’s experiences withVa i sala instruments have beeng o o d. So far, we have installedten systems with Va i sala sen-s o r s, and they have measuredup to our expectations. All thetransmitters are working fine.

The Ski Tunnel has attracted skiers from all over the wo r l d.

The housing of HMP 140 tra n s m i t t e rs provides IP65 protection

from dust and sprayed water, so these are suitable instruments for

humid spaces and outdoor installations.

■

T

31148/1998

In the Huurre Ski Tunnel in Finland,optimal conditions are always guaran-

t e e d. Va i sala transmitters play an impor-tant role at this indoor ski track, continu-ously measuring the prevailing humidity,

temperature and carbon dioxide levels.

he Vuokatti Ski Tr a i n-ing Center is locatedin central Finland.S kiers from all over

the world come here to train –even in the summer time. Th emain attraction is the 1.2 kmS ki Tu n n e l, which has a 2.4 kmnatural snow surface ski track.With curving trails and hills, theconditions are similar to natu-ral outdoor ski trails in every re-s p e c t.

Winter conditionsg u a r a n t e e d

The winter weather conditionsin the tunnel are optimal –there is snow and fresh air, butit is not too cold. Because theconditions are stable, weather-related risks and inconv e n-iences are not a factor. Anadvanced ventilation systemprovides humidity control andgood air quality. Humidity,temperature and carbon diox-ide levels are measured with

The NuAire Group produces

one of the world’s widest ranges

of ventilation fans and eq u i p-

m e n t, from domestic bathroom

and toilet extract fans to large

c o m m e r c i a l / i n d u s t rial units. Th e

company is also a mark e t

l eader in condensation control

equipment for public housing,

and has dev e l o p ed an industry

l eading range of ventilation con-

trols for the commercial sec t o r.

NuAire currently has customers

in over 25 countries worl d w i d e .

Lo c a t ed in Caerphilly, South

Wa l e s, United Kingdom, NuAire

has about 300 employees.

Hanne Österberg, BB A, B. S c. (C o m p. )M a r keting AssistantSensor Systems DivisionVa i sala HelsinkiF i n l a n d

N e ve r -Ending Wi n t e rStability minimizes the need forcalibration and maintenance,helping to reduce the total op-erating costs of the system.

The fan action is directly con-trolled by the sensors. When theo c c u p a n cy sensor detects peo-ple in the room and the carbondioxide level starts rising, thefan switches on, supplying theright amount of fresh air to ther o o m. This prevents the roomsfrom becoming stuffy and pro-vides healthier conditions forthe occupants. Since the fan isused only when needed, thiseliminates excess energy con-s u m p t i o n.

NuAire’s experiences withVa i sala instruments have beeng o o d. So far, we have installedten systems with Va i sala sen-s o r s, and they have measuredup to our expectations. All thetransmitters are working fine.

The Ski Tunnel has attracted skiers from all over the wo r l d.

The housing of HMP 140 tra n s m i t t e rs provides IP65 protection

from dust and sprayed water, so these are suitable instruments for

humid spaces and outdoor installations.

■

T

32 148/1998

Va i sala transmitters. The mainmeasurements are taken insidethe tunnel and from the inletand exhaust air of the refrigera-tion units. HMP 142 humiditytransmitters and GMD20 CO2transmitters are used to meas-ure humidity, temperature andcarbon dioxide in the ventila-tion ducts, while HMP 14 3transmitters measure the humid-ity and temperature of the snow.

M r. Ve sa -Pe kka Sarparanta,Executive Director of the HuurreS ki Tu n n e l, came up with theidea of the tunnel in the 19 8 0 s,when he was a trainer for theFinnish national cross countrys kiing team. “There was a clearneed for stable training condi-tions for competition ski e r s. Inthe summer, these conditionscan only be found at high alti-tudes – for example on glaciersat 1900 m. These are not goodtraining conditions, however,because they require daily trav-el and altitude adjustment. ”

After he saw snow making inl a b o r a t o ry conditions in Italy,M r. Sarparanta put his plans inm o t i o n. Construction of thehighly innovative Ski Tu n n e lb e gan in April 19 97 and was com-pleted in eight months.

Unique refrigerationsystem

Sabroe Finland Oy, a companywith extensive experience inrefrigeration tech n i q u e s, was incharge of the planning andimplementation of the refrigera-tion system for the Ski Tu n-n e l. Mr. Marko Matka v u o r i,Electrical Engineer from theSabroe project team, commentson the start of the project: “Werealized early in the planningstage that there would be somedifficult measuring points be-cause of the discrepant condi-tions caused by snow maki n gand other factors. We decidedon Va i sala’s measuring equip-ment at this time, based on its re-cognized quality and Va i sa l a ’ sgood technical support. ”

The air and snow tempera-ture and the air-conditioning inthe tunnel are monitored andcontrolled by computer tech-n o l o g y. The inside air andsnow temperatures are normal-ly between -5 and -9 °C, butcan be dropped to -18 °C ifneeded; even ice formation ispossible. The tunnel air is com-pletely exchanged every fourh o u r s. The snow making sys-tem consists of high pressurecannons that replenish the trails u rface at night when required,normally every two weeks.

The ventilation is controlledby measuring the carbon diox-ide levels so the amount offresh and exhaust air alwayscorresponds to actual demand.

Schematic drawing of the tunnel sys t e m.

This avoids any unnecessa ryload on the refrigeration sys-tem when there are no activ-ities in the tunnel.

Four machine rooms, eachwith a ventilation machine andtwo separate refrigerators con-taining a compressor and anexpansion coil, provide refrig-eration and ventilation. Th erooms are located above groundmore than 300 meters apart. Th em a chine rooms have program-mable controllers connected tothe Wi n d o w s -based monitor-ing program in the controlr o o m. These are wired with anRS485 bus. The system can beremote accessed and programmedthrough a modem in the mon-itoring computer. All Va i sa l a

transmitters are connected tothis system. The output datafrom the transmitters is fed tothe monitoring program fromw h i ch all settings, includingthe desired temperature, can bea l t e r e d.

Sabroe’s initial plans for thetunnel’s refrigeration systemhave been a success. Mr. Sarpa-ranta does see some futurech a l l e n g e s, however, as far asoptimization of the system isc o n c e r n e d. The relative humid-ity in the tunnel is normallybetween 85–95% RH.According to Ve sa -Pe kka Sarpa-ranta: “One possibility wouldbe to lower the humidity toaround 80% RH. No evapora-tion would take place at thispoint – so the snow itselfwould act as ‘a polar radiator’.Control of the humidity equi-librium in general is anotherkey issue.” The greatest sourcesof humidity peaks are snowm a king and the fresh air that isintroduced into the tunnel.

Landscaping is a future proj-e c t. Plans call for the tunnel tobe protected and concealed bya layer of soil, after which it will

Ve s a -Pekka Sa r pa ranta ha s

been pleased by the

international interest and

welcomes visitors to the Ski

T u n n e l.

33148/1998

GML20T and GMD20D

New CO2 Pro d u c t sComplement theGM20 Se r i e s

Two new productshave been added toVa i sala’s carbon diox-ide CA RBOCA P

®

transmitter series.When installed in theGM W 21 transmitter,the new GML 2 0 Tmodule makes it pos-sible to measure tem-perature in addition tocarbon dioxide levels.L i ke the previouslyl a u n ched GML 2 0module, the GML 2 0 Tis also compatiblewith LonWo r ks

®.

he GMD20D is adisplay version ofthe GMD20 ductm o u n t carbon diox-

ide transmitter. In Va i sa l a ’ sduct mount transmitters, thesensor head is inside the venti-lation duct. The display coveris especially useful for specialapplications and during calibra-tion ch e cks, for example.GMD 2 0 /D transmitters aresmall in size, and they offeroutstanding performance andv e r sa t i l i t y.

The GM20 series of carbondioxide transmitters is kn o w nfor its superior stability. Com-bined with the interoperabilityof LonWo r ks®, the result is ac o s t -effective, flexible and reli-able solution for buildingautomation systems.

The GML20T module, which is

installed inside the GMW21

t ra n s m i t t e r, enables carbo n

d i oxide and tempera t u r e

m e a s u r e m e n t s.

The duct mountable

t ransmitter GMD 2 0 D

with a digital display.

look much like a naturally occur-ring ridge.

A winter wonderland

The main purpose of the SkiTunnel is to provide facilitiesfor cross country skiing for bothcompetitors and fitness trainerswhen there is no snow outdoors.The tunnel is also ideal for test-ing cold-weather phenomenaand equipment in winter con-d i t i o n s. For companies whoseoperations and products areconnected to winter, includingmanufacturers of clothing, ski sand ski waxes, for example, it isan excellent facility for productdevelopment and testing. Otheractivities include medical stud-ies connected to exertion asth-ma or exposure to cold, as wellas industrial tests (of car tires,for example).

Tourists are another targetg r o u p. Mr. Sarparanta has beengratified by the international in-terest in the tunnel, which hasattracted some 20,000 visitorsfrom 40 countries. He expectsto see more ski tunnels in fu-ture. “After all,” he sa y s, “theyare based on the same principleas indoor swimming pools. ”

Ve sa -Pe kka Sarparanta has astrong background in bothengineering and Finland’s sport sscene, as well as a fascinationwith new ideas. In the past, hewas head trainer for Finland’scross country skiing team anddirector of the Vuokatti Ski Tr a i n-ing Center, which has been inexistence for 50 years and isFinland’s third largest sport sc e n t e r.

“ Va i sala has long experiencein measurement techniques andstrong kn o w -how – their trans-mitters have been a reliablechoice for us,” says Mr. Sarparantasumming up his experience withVa i sa l a. ■ ■

T

33148/1998

GML20T and GMD20D

New CO2 Pro d u c t sComplement theGM20 Se r i e s

Two new productshave been added toVa i sala’s carbon diox-ide CA RBOCA P

®

transmitter series.When installed in theGM W 21 transmitter,the new GML 2 0 Tmodule makes it pos-sible to measure tem-perature in addition tocarbon dioxide levels.L i ke the previouslyl a u n ched GML 2 0module, the GML 2 0 Tis also compatiblewith LonWo r ks

®.

he GMD20D is adisplay version ofthe GMD20 ductm o u n t carbon diox-

ide transmitter. In Va i sa l a ’ sduct mount transmitters, thesensor head is inside the venti-lation duct. The display coveris especially useful for specialapplications and during calibra-tion ch e cks, for example.GMD 2 0 /D transmitters aresmall in size, and they offeroutstanding performance andv e r sa t i l i t y.

The GM20 series of carbondioxide transmitters is kn o w nfor its superior stability. Com-bined with the interoperabilityof LonWo r ks®, the result is ac o s t -effective, flexible and reli-able solution for buildingautomation systems.

The GML20T module, which is

installed inside the GMW21

t ra n s m i t t e r, enables carbo n

d i oxide and tempera t u r e

m e a s u r e m e n t s.

The duct mountable

t ransmitter GMD 2 0 D

with a digital display.

look much like a naturally occur-ring ridge.

A winter wonderland

The main purpose of the SkiTunnel is to provide facilitiesfor cross country skiing for bothcompetitors and fitness trainerswhen there is no snow outdoors.The tunnel is also ideal for test-ing cold-weather phenomenaand equipment in winter con-d i t i o n s. For companies whoseoperations and products areconnected to winter, includingmanufacturers of clothing, ski sand ski waxes, for example, it isan excellent facility for productdevelopment and testing. Otheractivities include medical stud-ies connected to exertion asth-ma or exposure to cold, as wellas industrial tests (of car tires,for example).

Tourists are another targetg r o u p. Mr. Sarparanta has beengratified by the international in-terest in the tunnel, which hasattracted some 20,000 visitorsfrom 40 countries. He expectsto see more ski tunnels in fu-ture. “After all,” he sa y s, “theyare based on the same principleas indoor swimming pools. ”

Ve sa -Pe kka Sarparanta has astrong background in bothengineering and Finland’s sport sscene, as well as a fascinationwith new ideas. In the past, hewas head trainer for Finland’scross country skiing team anddirector of the Vuokatti Ski Tr a i n-ing Center, which has been inexistence for 50 years and isFinland’s third largest sport sc e n t e r.

“ Va i sala has long experiencein measurement techniques andstrong kn o w -how – their trans-mitters have been a reliablechoice for us,” says Mr. Sarparantasumming up his experience withVa i sa l a. ■ ■

T

34 148/1998

The new PTU200

Th re e - i n -One Tra n s m i t t e rfor PTU Measure m e n t sVa i sala’s new PT U 2 0 0t r a n s m i t t e r, which isbased on the design ofthe PTB220 digitalbarometer series, com-bines three measure-ment parameters: pres-sure, temperature andh u m i d i t y. The meas-urements can be usedto improve the accura-cy of GPS coordinatem e a s u r e m e n t s, esti-mate precipitablewater vapor in theatmosphere or per-form env i r o n m e n t a lmonitoring in calibra-tion laboratories.

a i sala has introduceda new PTU (pressure,temperature, humid-ity) transmitter for

G PS (Global Positioning System)meteorological and GPS coor-dinate measurement system ap-p l i c a t i o n s. With the new trans-m i t t e r, the effects of atmosphericwater vapor can be taken intoaccount in GPS measurements.

The accuracy of the GPScoordinate measurement sys-tem is affected by water vaporin the atmosphere. This effectcan be estimated, however,using accurate measurementsof the barometric pressure, airtemperature and relative humid-i t y at the GPS receiver antennale v e l. Based on these PTU meas-u r e m e n t s, the accuracy of thecoordinate measurement sys-tem can be further improved.

Measurements of the precipi-table water vapour in theatmosphere also have weather-related applications, so inv e s t-ments made in the global GPSsatellite and eart h -based receiv-er network benefit not onlygeodetic authorities, but alsom e t e o r o l o g i s t s.

Flexible configuration

The new PTU200 transmitter isbased on Va i sala’s PTB220 digi-tal barometer. A new measur-ing transducer, however, whichallows additional measurementof two 0 to 1 VDC inputs and/orone four-wire Pt100 resistive tem-perature sensor, has been devel-oped for the PTU200. A typicalPTU200 configuration consistsof a barometric pressure trans-ducer and the HMP 4 5 A -P orHMP45D probe.

The HMP 4 5 A -P relative hu-midity and temperature probeused with the PTU200 has athin film Pt1000 temperatures e n s o r. Th a n ks to the 20-m e t e rconnection cable, the probe canbe installed at a greater distancefrom the barometer when need-e d. The HMP45D humidity andtemperature probe has a thinfilm Pt100 temperature sensor,and it comes with a 3.5-m e t e rconnection cable.

When humidity measure-ment is not required, thePTU200 can be supplied with as m a l l, high stability wire-t y p eP t 100 temperature sensor head.

The same sensor head has beenused previously for the externaltemperature sensor in theHMP243 dewpoint transmitters e r i e s.

An RS232 serial interface isstandard with PTU200 trans-m i t t e r s. The transmitter softwareis also compatible with majorG PS receivers and NMEA (N a-tional Marine Electronics Asso-c i a t i o n) coded messa g e s. Th ePTU200 transmitter is availablewith a local display and an RS 4 8 5serial interface as options. Twototal accuracy classes for pres-sure – class A (±0.10 hPa) andclass B (±0.20 hPa) – are avail-a b l e .

Careful installationr eq u i r e d

For GPS applications, the PT Utransmitter is often installedo u t -o f -d o o r s. In these cases,users must pay careful atten-tion to the proper protection ofthe temperature and humidityprobe from solar radiation andr a i n. The site must be selectedaccording to established WMOr e q u i r e m e n t s. It must be repre-

Pe kka Järv i, M. S c. (E n g. )Product ManagerSensor Systems DivisionVa i sala HelsinkiF i n l a n d

¥

V

PTU200 transmitter with an HMP 4 5 A-P probe.

35148/1998

Outdoor mounting of the PTU200 tra n s m i t t e r.

Single waves in the northern Baltic Sea canr e a ch as high as 10 meters, and the wave condi-tions can be severe, especially in the Gulf ofB o t h n i a. A marine meteorological buoy hasbeen installed to measure weather conditionsand waves in the Baltic Sea. The buoy isequipped with Va i sala’s digital barometerdesigned for extreme marine conditions.

sentative of the general atmos-pheric conditions, and theunderlying ground must besuitable for relative humidityand temperature measurement.F u rthermore, a static pressurehead is needed to minimizew i n d -induced error in baromet-ric pressure measurement.

For outdoor use of thePTU200 transmitter, Va i sa l aoffers an optimized outdoormounting kit – the PT U 2 0 0 MIK– so PTU measurements can bemade at the site of the GPSa n t e n n a. The PT U 2 0 0 MIK in-cludes a weatherproof box forthe barometer of the PT U 2 0 0t r a n s m itter and a radiationshield for the humidity andt e mperature probe. The PT U-2 0 0 T RIPOD tripod, whichVa i sala also supplies, isdesigned for use with the PT U-2 0 0 MIK outdoor mounting ki tand ensures portability andq u i ck system set-u p.

The PTU200 transmitter canr e p o rt both the measured pres-sure at the barometer level andpressure reduced to the site-specific GPS antenna level.This makes it easy to differenti-

ate the pressure calibrationinformation from GPS applica-t i o n -related pressure readings.

Suitable for calibrationl a b o r a t o r i e s

The PTU200 transmitter is alsoan excellent solution for moni-toring calibration laboratory en-v i r o n m e n t s, in particular whena single multiparameter trans-mitter for environmental pres-su r e , temperature and relativeh umidity is required. While thePTU200 transmitter presentsthe prevailing conditions on itslocal display cover, a computercan simultaneously register thePTU conditions at a specifiedpoint in time through thetransmitter’s serial interf a c e .The environmental parameters,in turn, are then combined withthe actual calibration informa-t i o n.

Ad va n c e dM a r i n eM o n i t o r i n gI m p rove sN a v i g a t i o nSa fe t y

Ad va n c e dM a r i n eM o n i t o r i n gI m p rove sN a v i g a t i o nSa fe t y

New meteorological buoy in the Baltic Sea

According to Osmo

Korhonen from FIMR,

the buoy will improve

shipping safety on the

Baltic Se a.

■

Marit FinneE d i t o r -i n -C h i e f

Va i sala Ne w sVa i sala Helsinki

F i n l a n d

35148/1998

Outdoor mounting of the PTU200 tra n s m i t t e r.

Single waves in the northern Baltic Sea canr e a ch as high as 10 meters, and the wave condi-tions can be severe, especially in the Gulf ofB o t h n i a. A marine meteorological buoy hasbeen installed to measure weather conditionsand waves in the Baltic Sea. The buoy isequipped with Va i sala’s digital barometerdesigned for extreme marine conditions.

sentative of the general atmos-pheric conditions, and theunderlying ground must besuitable for relative humidityand temperature measurement.F u rthermore, a static pressurehead is needed to minimizew i n d -induced error in baromet-ric pressure measurement.

For outdoor use of thePTU200 transmitter, Va i sa l aoffers an optimized outdoormounting kit – the PT U 2 0 0 MIK– so PTU measurements can bemade at the site of the GPSa n t e n n a. The PT U 2 0 0 MIK in-cludes a weatherproof box forthe barometer of the PT U 2 0 0t r a n s m itter and a radiationshield for the humidity andt e mperature probe. The PT U-2 0 0 T RIPOD tripod, whichVa i sala also supplies, isdesigned for use with the PT U-2 0 0 MIK outdoor mounting ki tand ensures portability andq u i ck system set-u p.

The PTU200 transmitter canr e p o rt both the measured pres-sure at the barometer level andpressure reduced to the site-specific GPS antenna level.This makes it easy to differenti-

ate the pressure calibrationinformation from GPS applica-t i o n -related pressure readings.

Suitable for calibrationl a b o r a t o r i e s

The PTU200 transmitter is alsoan excellent solution for moni-toring calibration laboratory en-v i r o n m e n t s, in particular whena single multiparameter trans-mitter for environmental pres-su r e , temperature and relativeh umidity is required. While thePTU200 transmitter presentsthe prevailing conditions on itslocal display cover, a computercan simultaneously register thePTU conditions at a specifiedpoint in time through thetransmitter’s serial interf a c e .The environmental parameters,in turn, are then combined withthe actual calibration informa-t i o n.

Ad va n c e dM a r i n eM o n i t o r i n gI m p rove sN a v i g a t i o nSa fe t y

Ad va n c e dM a r i n eM o n i t o r i n gI m p rove sN a v i g a t i o nSa fe t y

New meteorological buoy in the Baltic Sea

According to Osmo

Korhonen from FIMR,

the buoy will improve

shipping safety on the

Baltic Se a.

■

Marit FinneE d i t o r -i n -C h i e f

Va i sala Ne w sVa i sala Helsinki

F i n l a n d

36 148/1998

In April 1998, a marine meteoro-logical buoy was installed inthe open Baltic Sea, 35 milesoff the western coast of Finland( 61° 48’N 20° 14 ’ E). The buoyis 2.8 meters in diameter. It ismaintained by the FinnishInstitute of Marine Research(FIMR), the Finnish Meteorol-ogical Institute (F MI) and theFinnish Marine Ad m i n i s t r a t i o n.

Hourly reports onmarine wea t h e rc o n d i t i o n s

M r. Osmo Korhonen, Head ofFIMR’s Field and Serv i c eG r o u p, was one of the key peo-ple behind the new marine me-teorological installation. As hee x p l a i n s, the marine and me-teorological data collected bythe buoy will increase shippingsa f ety and improve the qualityof local weather forecasts. Th esa m e r e a l -time marine weatherdata is also available to thepublic via radio or FMI ’ sphone serv i c e .

The new buoy, which meas-ures air temperature and pres-sure, wind speed and direction,sea water temperature, wavesand surface sea currents, is theonly permanently moored buoyin the northern part of theBaltic Sea. Once an hour, thecollected data is automaticallytransferred via the Inmarsa t -Csatellite system to the FinnishMeteorological Institute. Sochanges in weather and wave

conditions can be monitoredalmost in real-time. If needed –during a storm, for instance –data can be collected every 30m i n u t e s. The database will alsobe used for climatological re-s e a r ch and statistics.

“ The buoy is mainly power-ed by solar energy, althoughlithium batteries take over inthe dark,” notes Mr. Korhonen.“From December to April, whenthe sea is frozen, the buoy willbe maintained on land. It willbe re-installed in the sa m eplace after the ice breaks up inthe spring. ”

Accurate and stabledigital barometer

The newly installed Oceanorbuoy is equipped with a Va i sa l aPTB200A barometer to measureair pressure. Th a n ks to its low cur-rent consumption, the PT B 2 0 0 Adigital barometer can be pow-ered by solar energy at remotesites like marine buoys. Th ebarometer is accurate and sta-ble over a wide pressure and tem-perature range.

The Baltic Sea is an impor-tant research target for theFinnish Institute of MarineR e s e a r ch. According to Mr.K o r h o n e n, Va i sala’s PT B 2 0 0 Ameets their performance require-ments for cost-effective ande a s y -t o -maintain sensors for ma-rine use. The PTB200A hasbeen used for five years on vari-ous Oceanor buoys.

Vaisala’s PTB200A ba r o m e t e rs (left) have been used for five

y e a rs on Oceanor buoys.

Osmo Ko r h o n e n, Head of FIMR’ s

Field and Service Gr o u p, was one of

the key people behind the new marine

meteorological buoy installation.

After an extensive test-ing process, the Japan

M e t e o r o l o g i c a lA g e n cy decided to

incorporate Va i sa l a ’ sinstruments in their

model JMA-95 auto-matic surface weather

s t a t i o n s. Va i sa l abarometers have

already proven theirstability and reliability

in tests and in thef i e l d.

a i sala’s business inJapan began morethan twenty yearsago when the Me-

teorological Research Institute ofthe Japan Meteorological Agen-cy (J M A) installed Va i sa l a ’ sHMP 14U humidity probes intheir newly erected observ a t o ryt o w e r s. Th e probes were sup-plied through Sanko TsushoC o., Ltd.

The Agency’s model JMA-80automatic surface weather sta-t i o n s, which were introduced in1980, use barometers with a vi-brating cylinder sensor to meas-ure atmospheric pressure. Th elatest model JMA-95 automatics u rface weather stations, how-e v e r, are equipped with Va i sa l abarometers with a capacitiveB A R OCAP® s e n s o r.

In addition to PTB200AD andPTB220 digital barometers, theJapan Meteorological Agencyhas incorporated HMP233 hu-midity and temperature trans-m itters and FD 12P presentweather sensors in their observ a-tion networks.

A Vaisala HMP 2 3 3 L -J M

humidity transmitter with

a JMA radiation shield

installed in a JMA- 9 5

automatic surface weather

s t a t i o n. JMA’s head office

in Tokyo is in the

ba ck g r o u n d.

I sao NaitoArea Manager Va i sala To ky oJ a p a n

■

V

36 148/1998

In April 1998, a marine meteoro-logical buoy was installed inthe open Baltic Sea, 35 milesoff the western coast of Finland( 61° 48’N 20° 14 ’ E). The buoyis 2.8 meters in diameter. It ismaintained by the FinnishInstitute of Marine Research(FIMR), the Finnish Meteorol-ogical Institute (F MI) and theFinnish Marine Ad m i n i s t r a t i o n.

Hourly reports onmarine wea t h e rc o n d i t i o n s

M r. Osmo Korhonen, Head ofFIMR’s Field and Serv i c eG r o u p, was one of the key peo-ple behind the new marine me-teorological installation. As hee x p l a i n s, the marine and me-teorological data collected bythe buoy will increase shippingsa f ety and improve the qualityof local weather forecasts. Th esa m e r e a l -time marine weatherdata is also available to thepublic via radio or FMI ’ sphone serv i c e .

The new buoy, which meas-ures air temperature and pres-sure, wind speed and direction,sea water temperature, wavesand surface sea currents, is theonly permanently moored buoyin the northern part of theBaltic Sea. Once an hour, thecollected data is automaticallytransferred via the Inmarsa t -Csatellite system to the FinnishMeteorological Institute. Sochanges in weather and wave

conditions can be monitoredalmost in real-time. If needed –during a storm, for instance –data can be collected every 30m i n u t e s. The database will alsobe used for climatological re-s e a r ch and statistics.

“ The buoy is mainly power-ed by solar energy, althoughlithium batteries take over inthe dark,” notes Mr. Korhonen.“From December to April, whenthe sea is frozen, the buoy willbe maintained on land. It willbe re-installed in the sa m eplace after the ice breaks up inthe spring. ”

Accurate and stabledigital barometer

The newly installed Oceanorbuoy is equipped with a Va i sa l aPTB200A barometer to measureair pressure. Th a n ks to its low cur-rent consumption, the PT B 2 0 0 Adigital barometer can be pow-ered by solar energy at remotesites like marine buoys. Th ebarometer is accurate and sta-ble over a wide pressure and tem-perature range.

The Baltic Sea is an impor-tant research target for theFinnish Institute of MarineR e s e a r ch. According to Mr.K o r h o n e n, Va i sala’s PT B 2 0 0 Ameets their performance require-ments for cost-effective ande a s y -t o -maintain sensors for ma-rine use. The PTB200A hasbeen used for five years on vari-ous Oceanor buoys.

Vaisala’s PTB200A ba r o m e t e rs (left) have been used for five

y e a rs on Oceanor buoys.

Osmo Ko r h o n e n, Head of FIMR’ s

Field and Service Gr o u p, was one of

the key people behind the new marine

meteorological buoy installation.

After an extensive test-ing process, the Japan

M e t e o r o l o g i c a lA g e n cy decided to

incorporate Va i sa l a ’ sinstruments in their

model JMA-95 auto-matic surface weather

s t a t i o n s. Va i sa l abarometers have

already proven theirstability and reliability

in tests and in thef i e l d.

a i sala’s business inJapan began morethan twenty yearsago when the Me-

teorological Research Institute ofthe Japan Meteorological Agen-cy (J M A) installed Va i sa l a ’ sHMP 14U humidity probes intheir newly erected observ a t o ryt o w e r s. Th e probes were sup-plied through Sanko TsushoC o., Ltd.

The Agency’s model JMA-80automatic surface weather sta-t i o n s, which were introduced in1980, use barometers with a vi-brating cylinder sensor to meas-ure atmospheric pressure. Th elatest model JMA-95 automatics u rface weather stations, how-e v e r, are equipped with Va i sa l abarometers with a capacitiveB A R OCAP® s e n s o r.

In addition to PTB200AD andPTB220 digital barometers, theJapan Meteorological Agencyhas incorporated HMP233 hu-midity and temperature trans-m itters and FD 12P presentweather sensors in their observ a-tion networks.

A Vaisala HMP 2 3 3 L -J M

humidity transmitter with

a JMA radiation shield

installed in a JMA- 9 5

automatic surface weather

s t a t i o n. JMA’s head office

in Tokyo is in the

ba ck g r o u n d.

I sao NaitoArea Manager Va i sala To ky oJ a p a n

■

V

37148/1998

Vaisala is the first foreign supplier of

N e t work Sensors for the Japan Meteorological Agency

Applying the latestt echnology tom e t eo r o l o g i c a lo b s e r va t i o n s

According to legislation concern-ing the Meteorological Serv i c eof Japan, governmental agen-cies (other than JMA) must useinstruments tested and cert i f i e dby JMA in meteorological ob-s e rv a ti o n s. Continuous tech n o-l o g i c a l d e v e l o p m e n t, however,brings innovative instrumentsbased on new measurementprinciples to the market all thetime. In recognition of the ben-efit of these new tech n o l o g i e sand the need to make themavailable to the public, the Or-dinance of the Ministry of Tr a n s-p o rt on the Certification Pro-cedure of Meteorological Instru-ments was reviewed during thefinalization process for thespecifications of the modelJMA-95 automatic surface weath-er stations.

As a result, the ministerialordinance was partially revised,and Va i sala’s PTB200 series dig-ital barometers and HMP 2 3 0series digital humidity transmit-t er s, representing new and inno-v ative tech n o l o g y, were finallylisted as products subject to thec e rtification procedure.

Performance anddurability tests

JMA began the selection ofacceptable instrument compo-nents for its model JMA-95 sur-face weather stations yearsbefore the official introductionof the stations. During this pe-r i o d, a variety of perf o r m a n c eand durability tests, includingthose listed below, were con-ducted on the individual in-struments of various manufac-t u r e r s :

Figure 3. Meteorological stations in Ja pa n. Courtesy of the Ja pan Meteorological Agency.

38 148/1998

• Stability comparison test forone year.

• Temperature ch a r a c t e r i s t i ctests at temperatures of -20 °C, 0 °C, 30 °C and 50 ° C .

• Absolute pressure compari-son tests at five differento b s e rvation points with sta-tion pressures of 880 hPa,920 hPa, 980 hPa, 1000 hPaand 1040 hPa; as part of thetesting process, accuracyand hysteresis were studiedat increasing and decreasingp r e s s u r e .

• Accelerated stability test,equivalent to an operationperiod of 700 days, inv o l v-ing a recovery in pressurefrom approximately 30 hPalower than the station pres-sure to a normal level ati n t e rvals of 5 minutes.

• Vibration test at a magni-tude of ±2 mm and a vibra-tion frequency of 300 rpm.

Following these tests, JMA evalu-ated prospective products fortheir integrity, price, expand-ability and the manufacturer’ss u p p o rt system. On this basis,the Agency decided in 1995 toprocure Va i sala’s productsthrough Meisei Electric Co., Ltd. ,w h i ch has been acting as thesystem integrator of the modelJMA-95 automatic surface weath-er stations. This screening pro-cess yielded valuable adviceand suggestions for Va i sa l a.The contribution of Pe kka Järv i,Va i sala’s Product Manager, alsoplayed an important role in thesuccessful outcome.

Reading comparisons ofthe PT B 2 20 barometer

To ensure the digital barom-eter’s long-term stability andch e ck the adequacy of its peri-odical inspection and mainte-nance, the Agency made con-stant comparison readings ofthe digital barometers withthose of Fortin mercury barom-eters for more than a year. Th ereading errors recorded forVa i sala’s barometers fell withina range of ±0.15 hPa without asystematic change in eitherd i r e c t i o n, which verified theirstability performance for a ser-vice life of at least two years(see Figure 1) .

JMA operates 161 surf a c eob s e rvation stations throughout

J a p a n, including 57 meteoro-logical observatories and 10 4weather stations (see Figure 3).Since some of these observ a-tories and stations are unmanned,automatic meteorological instru-ments have been installed int h e m. Of these automatic in-s t r u m e n t s, the Agency part i c u-larly appreciates Va i sala’s PT B 2 2 0barometers with three pressuretransducers because of their out-standing reliability. JMA has usedthe barometers since fiscal year1996 (see Figure 2).

The PT B 2 2 0 TS traveling/transfer standard barometerwas lately developed by Va i sa l ato support PTB220 barometers.This year, JMA has also accept-ed this model, an extension ofthe PTB220 series, as a port a b l estandard barometer for marinemeteorological observ a t o r i e s.The standard barometer is usedfor periodical calibration ofshipboard barometers that meas-ure atmospheric pressures uponthe request of JMA. ■

Figure 1. A nine-

month compa r i s o n

of Va i s a l a ’ s

PTB 2 0 0 AD

digital ba r o m e t e r

against the Fo r t i n

mercury ba r o m e t e r

using the prev a i l i n g

m e t h o d.

Figure 2. A nine-

month compa r i s o n

of Va i s a l a ’ s

PTB 2 0 0 AD

digital ba r o m e t e r

against the Fo r t i n

mercury ba r o m e t e r

using a different

calculation method.

Vaisala’s PTB 2 0 0 AD digital barometer (on the left )

installed in a JMA-95 automatic surface weather

s t a t i o n.

39148/1998

Vaisala KK celebrates its 15th anniversary

Meeting Wi d e -Ranging Needs in Japan

Established in 1983, Va i sala KKmade its market entry in Japanwith humidity meter sa l e s. To d a y,Va i sala’s humidity sensors andinstruments have gained a sizableshare of the country’s marke t.Va i sala KK is celebrating its 15 t ha n n i v e r sa ry in 1998, and thec o m p a ny’s future in Japan looksp r o m i s i n g.

a i sala KK, or Va i sa l aTo ky o, was e s t a b-lished in May 19 8 3 .This event was pre-

ceded by a ten-y e a r p e r i o d, dur-ing which Va i sala products, pri-marily humidity meters, werei m p o rted and distributed by twolocal compan i e s, Sanko Tsushoand Phoenix I n t e r n a ti o n a l. So25 years have passed since t h efirst Va i sala products made theirappearance in Japan.

As early as 19 87, Va i sala estab-l i s h e d a branch office in Osa ka,to serve Ka n sa i, Japan’s secondlargest economic area.

Success story from theb eg i n n i n g

Va i sala KK’s first priority wasto establish a marketing andsales program for humidityinstruments and to begin gen-

erating sa l e s. The company wasa success from the very begin-n i n g. Electronic humidity metersfirst penetrated the market inthe early 19 8 0 s. Their advantagesover traditional psych r o m e t e r sand other humidity meters wereobvious: they were faster andmore accurate, they could beconnected to PCs.

To meet the demand for elec-tronic humidity measurement,Va i sala developed the renown-ed HUMICAP ® sensor in 1973 .This humidity sensor, based onthe capacitive measurementprinciple, was soon adopted fornumerous applications in thee nvironmental and industrialf i e l d. In the mid-19 8 0 s, Japa-nese industry was hungry fornew technologies to improvequality and productivity, so thetime was right for electronic hu-midity transmitters.

Va i sala’s products found theirway to the HVAC (heating, ven-tilation and air conditioning)i n d u s t ry, where the stability, ac-c u r a cy and electronic outputsignal of humidity and tempera-ture are of prime import a n c e .Y a m a t a ke Honeyw e l l, the mar-ket leader for demanding HVA Cin s t a l l a t i o n s, started to use Va i-sala transmitters, and many othercompanies soon followed theire x a m p l e .

After the founding of Va i sa l aKK, the former import e r s, SankoTsusho and Phoenix Interna-t i o n a l, became Va i sala distribu-t o r s. This was extremely impor-tant in order to guarantee asmooth and continuous rela-tionship with existing local cus-t o m e r s. The technical kn o w l-edge of these companies wason high level, further enhanc-ing the services they offered.

Part of the Vaisala Tokyo staff in 19 97.

Rauno SirolaP r e s i d e n tVa i sala To ky oJ a p a n

V

40 148/1998

Strong commitment to training

The realization was soon madethat calibration facilities forhumidity transmitters were ab-solutely essential in Japan. Th el a ck of calibration premises, agrowing need for storage spaceand more people created pres-sure to enlarge our premises. In1988 Va i sala KK moved to anew office in Shinjuku, wherethe necessa ry calibration andstorage facilities could be built.Located in the building acrossfrom the Ka g u r a z a ka under-ground station in central To ky o,the office will probably sufficefor some time.

Va i sala To kyo currently has24 employees, as well as severalte m p o r a ry staff and part -t i m e r s.The workforce has increased intandem with sa l e s.

The company’s policy is toprovide continuous personneltraining to improve the staff ’ sprofessional skills and, in par-t i c u l a r, their technical kn o w l-edge of Va i sala equipment.

The training takes place inJapan and at Va i sala’s head-q u a rters in Finland. The regularvisits of Va i sala’s product man-agers and other technical staffto Japan further strengthen theteamwork in this internal edu-cation process.

Targeting other upperair and surface wea t h e ra p p l i c a t i o n s

Va i sala KK launched upper airsales in Japan in 1986, when thefirst equipment was deliveredto Kyoto University. This wasfollowed by deliveries to theJapan Meteorological Agency(J M A), which was equippingtheir meteorological researchvessels with sounding systems.Va i sala developed the ASAP(Automatic Shipboard Aero-logical Program) container inclose cooperation with JMA foruse onboard their observ a t i o ns h i p s. Radiosondes and Omega -ba s e d windfinding systems havebeen delivered since. In re-sponse to the phase-out of theO m e ga system in 19 97, GPSwindfinding was adopted forupper air observ a t i o n.

To d a y, more than twentyVa i sala radiosonde systemshave been delivered to Japan.JMA and many research orga-nizations have taken advantageof Va i sala’s cost-effective ande a s y -t o -operate upper air equip-m e n t.

Because winter weather has asignificant impact on road andr u nway conditions in nort h e r nJ a p a n, Va i sala ice monitoring andprediction systems have beenadopted in the region. Sincethe first installation at Sapporoa i r p o rt on Hokkaido in late1992, dozens of new ice moni-toring systems have been install-e d in cooperation with Va i sa l a ’ sp a rt n e r, Mitsui & Co., Ltd.

Va i sala’s surface weather sys-tems are equipped with reli-able, high-quality sensors, in-cluding ceilometers, visibilitymeters and wind sensors. Th eJapanese authorities have gradu-ally accepted many of them.Va i sala’s cooperation withMeisei Denki and Yo ko ga w aWe a t h a c, two large Japaneseweather observation system sup-p l i e r s, has resulted in appropri-ate products, including Japa-nese software, for the Japanesee nv i r o n m e n t.

Stamp of approval from JMA

Several years ago, JMA wasfaced with the need to upgradethe humidity and pressure sen-sors in their observation net-w o r k. Before replacing thehumidity and pressure instru-m e n t s, the Agency conductedtwo years of tests. Based on ther e s u l t s, Va i sala became the firstforeign supplier to receive JMAapprovals for network sensors.The first Va i sala sensors to beJ M A -approved for standard use

in Japan were the HMP 2 3 3humidity transmitter and thePTB200AD pressure transmit-t e r. In 1995, when the approvalwas granted, they were the firstn o n -Japanese sensors for JMA’ ssynoptic stations. The projectto install HMP233 andPTB200AD transmitters in allof Japan’s synoptic weather sta-tions is continuing.

As shown by these examples,Va i sala KK’s history is veryclosely connected with thedevelopment of Va i sala sen-s o r s. It is not unusual forJapanese end-users to want tot ry new technologies as soon asthey become available. Start i n gup regular business, however, isanother matter. Typically, thetesting and approval processt a kes years, and only then aree n d -users convinced that thenew sensor is appropriate forJ a p a n. The results of tests madeelsewhere cannot be used, so itis difficult to speed up thep r o c e s s.

S t eady grow t h

Tr a d i t i o n a l l y, many govern-ment tenders have been restrict-ed to Japanese companies. Me-teorological equipment and sys-tems have been no exception.In recent years, however, theprocedures have been graduallyl i b e r a l i z e d, and a major deregu-lation program is now under-w a y. The ultimate goal is to cre-ate a free marke t. The publicauthorities benefit from theopen competition between Japa-nese and foreign companies,w h i ch offer their best and mostco s t -effective equipment. Th e s echanges are likely to affect allc o m p a n i e s, including Va i sa l a.

Va i sala’s customers in Japanare predominantly in the pri-vate sector. Applications covera wide range, and some Va i sa l aproducts have become the mar-ket leaders in the country. Th eaverage annual sales increase h a sbeen around 20 per cent form a ny y e a r s, and steady growthis also predicted for the future.L o o king ahead, Va i sala To ky oplans to concentrate more thanever on helping Japanese cus-tomers successfully meet theire nvironmental measurementand data acquisition needs.

It is Va i sala To kyo’s privi-leged goal to maintain a closeconnection with the customersand end-users in the Japanesec o m m u n i t y.

Isao Naito smiles with pleasure aft e r

the successful GPS upgrade project

o n board the Chofu Ma r u, which is

one of JMA’s four observation ships.

Vaisala KK takes active part in Ja panese trade shows three to five times a year. Mr. Yuji Otake

stands beside the humidity and temperature instruments at Vaisala’s bo o t h.

■

41148/1998

P roduct Training in To k y o

A regional Sensor Systems’ product training course was held atVaisala Tokyo’s premises during the first week of July. Pa rt i c i p a n t swere from Japan, nea rby Asian countries and Australia.

The training sessions covered topics related to Vaisala’s new car-bon dioxide products, humidity and dewpoint sensors, and pressurep r o d u c t s. Mr. Juhana Häkkänen from Vaisala Helsinki, Sensor SystemsD i v i s i o n, supervised the training.

Pe kka Järv i, M. S c. (E n g. )Product ManagerSensors Systems DivisionVa i sala HelsinkiF i n l a n d

The PT B 2 2 0 TS Travels We l lor easy transport, Va i-sala’s digital PT B 2 2 0barometers are nowavailable with a stur-

dy wooden carrying case. Th i sa l l -i n -one unit can be used as ap o rtable barometer, transfer ortraveling standard and labora-t o ry working standard. In addi-tion to a digital PTB220 barom-et e r, the PT B 2 2 0 TS kit in-cludes an oak case, a sealed leadacid battery and recharging elec-t r o n i c s.

Stable and accurateBAR O CAP®

Digital PTB220 barometers aresturdy instruments that arehighly suitable for port a b l ea p p l i c a t i o n s. The robust fea-tures of the silicon BAROCA P®

absolute pressure sensor areone of the reasons behind theruggedness of the PTB220, whichcan be transported by normalsu rface and air mail without theneed for special handling.

PTB220 barometers also offerexcellent long-term stabilityand very low temperature depend-ence. Even when subjected to

Va i sala’s PT B 2 2 0barometers have nowbeen transformed intop o rtable units that canbe used as travelingand transfer standards.A sturdy wooden caseprotects the barom-et e r, while the inherentstability and accuracyof the silicon BARO-CAP

®pressure sensor

guarantees high meas-urement perf o r m a n c ein all conditions.

An integral valve keeps thepressure port of the PT B 2 2 0 TSclosed during transport andstorage; this valve opens formeasurement when a pressureconnector is mounted on theb a r o m e t e r.

The oak is specially treatedfor water-resistance. The upperp a rt of the outer box also con-tains a compartment for carry-ing small objects.

Easy-to-charge battery

The sealed lead acid battery ofthe PT B 2 2 0 TS offers 10 hoursof continuous use (with a back-lit display). The lead battery isnormally recharged overnight,but it can also be rech a r g e dwith a car battery, using a spe-cial cable that comes with thePT B 2 2 0 TS.

In this case, the cable is usedto connect the barometer to

the cigarette lighter socke t.‘ O n -t h e -road recharging’ enableseven greater portability of thePT B 2 2 0 TS.

Flexibility – within limits

Because of the pressure stand-ard nature of the PT B 2 2 0 TS, itis only available with a limitedselection of PTB220 seriesbarometer configurations. ClassA is the only accuracy classavailable, although users mayselect any level of measurementr e d u n d a n cy, i.e. one, two or threeintegrated pressure transducersin one barometer. A backlit dis-play and both RS232 andRS485 serial interfaces are alsostandard with the PT B 2 2 0 TSb a r o m e t e r.

The PTB 2 2 0 TS case is made from oa k. It consists of

an outer case used for transport and carrying and an

inner case where the barometer is mounted.

the roughest handling, theBA R OCAP pressure sensor main-tains its accuracy.

P r o t ec t i ve oak case

The wooden carrying case ofthe PT B 2 2 0 TS is made fromo a k. It consists of an outer casethat protects the barometer dur-ing transport and an inner casewhere the barometer is mount-ed (see photograph) .

In the laboratory, the PT B 2 2 0barometer and its inner case canbe used as a table-top barometeror a laboratory working stand-a r d. The inner case can also bemounted on the bottom half ofthe outer case and then tilted,allowing easy visibility of thebarometer display. If the unitneeds to be transport e d, thebarometer and inner case canbe fitted into the outer carry i n gc a s e .

Handy portable standard for barometric pressure

■

F

Lecture participants at the Sensor Systems’ product training session.

42 148/1998

Marit FinneE d i t o r -i n -C h i e fVa i sala Ne w sVa i sala HelsinkiF i n l a n d

Va i sala has alwaysbeen strongly commit-

ted to developing itsquality functions andimproving customersa t i s f a c t i o n. JaakkoLa u r i kainen is therecently appointed

Quality Manager ofVa i sala’s Sensor

Systems Division. Inhis work, he empha-

sizes clear targets,measurable processesand zero defect levels

to ensure productq u a l i t y.

he Va i sala QualitySystem is based ontotal quality controlfrom design to after

sa l e s. The Quality System isc e rtified to meet ISO 9001 andA Q A P - 110 standards. IEC andEN standards are mainly usedfor type approvals and perf o r-mance testing of Va i sala prod-u c t s.

J a a kko La u r i kainen wasappointed Quality Manager ofVa i sala’s Sensor Systems Divi-sion effective 1 April 1998. Pri-marily responsible for develop-ing quality activities, he is alsoin charge of after sales processdevelopment that supports cus-tomer service, feedback andcorrective actions within the di-v i s i o n. His qualifications in-clude an M. S c. degree in engi-n e e r i n g, and he has specializedin circuit design, semiconduc-tor physics and working psy-ch o l o g y. During his worki n glife, Mr. La u r i kainen has alsostudied quality theory.

Strong commitment toq u a l i t y

Va i sala Sensor Systems’ clearproduct concept supports totalquality management and im-proves the predictability of proj-ect outcomes. The quality or-ganization has been developedto meet the challenges of adynamic working env i r o n m e n t.

M r. La u r i kainen describeshis first few months in his newposition: “The customer’s pointof view is essential in all opera-ti o n s. Our team is strongly com-

mitted to the overall objectivesof product quality. In everycase, we place special emphasison information flow and dis-p e r sal throughout the qualityo r ga n i z a t i o n. ”

To conv e rt measurement datainto team and process-r e l a t e dproactive steering information,a ‘Visual Factory’ concept isbeing implemented. After ananalysis based on SPC (S t a t i s t i-cal Process Control), the data isdisplayed right beside processequipment or at the team’sw o r ks t a t i o n.

Statistical thinking in quality improvement.

Jaakko Laurikainen

was appointed

Quality Manager of

Vaisala’s Se n s o r

S ystems Division

effective 1 April

19 9 8. He is

primarily responsible

for developing quality

a c t i v i t i e s.

ReduceCommonCauseVariation

ImprovedQuality

SatisfiedCustomer

AnalyzeProcessVariation

“ProcessesAreVariable”

“All WorkIs AProcess”

ChangeProcess

è

è è è è

è

DevelopProcessKnowledge

ReduceVariation

è

Achieving Improvements Th rough

Total quality management

ControlProcess

RemoveSpecialCauseVariation

T

¥

43148/1998 43148/1998

“ Ta king customer feedbackinto account, we aim for meas-urable customer sa t i s f a c t i o n.We have to be able to meet cus-tomers’ needs and keep thepromises we make to them. Weare striving for a zero defectl e v e l. All this with a smile anda service mindset. ”

Setting clear targets forquality processes

Key processes are critical to thesuccess of an organization –and as such, they are prioritytargets for any improvementw o r k. Core processes are thoseactivities that add value for cus-t o m e r s.

J a a kko La u r i kainen empha-sizes that all processes must bemeasurable in order to verifythe results. “Measurement is aprerequisite for constant devel-o p m e n t. After defining anddocumenting the processes andthe essential measurementp o i n t s, Va i sala has integrated theminto its quality system. ”

To improve the quality pro-c e s s, the critical factors of cus-tomer satisfaction have beend e f in e d. Mr. La u r i kainen de-scribes the targets of qualitydevelopment: “The processparameters that we have de-fined allow us to evaluate ourp e rformance throughout theproduct process. This is part i c u-larly important in order tomeet high standards for quality.The product failure rate is ke p tlow through process monitor-ing and measurement. In otherw o r d s, this concerns all ouro p e r a t i o n s, not only produc-tion processes. We should alwaysaim for the highest quality. ”

Multi-functional qualityt ea m

Pr o c e s s -f o c u s e d, multi-f u n c t i o n-al quality teams can dramatical-ly improve the manufacturingand delivery of goods and ser-v i c e s. “To develop a processorientation within the compa-ny, we need to monitor activ-ities and tasks that produce agiven result. If any problemso c c u r, we have to react in timeto take corrective action. ”

M r. La u r i kainen agrees thatcustomer satisfaction is closelyrelated to quality. “Our cus-tomers are satisfied when prod-ucts and service match theirexpectations – the image theyhave in mind. Simple indica-tors of satisfied customers arerepeat business and no returnsfor product repairs or replace-m e n t. Customer satisfaction isnever fully achieved; once your e a ch a certain level, the stand-ards rise to the next and higherl e v e l. ”

Measurement and Process An a l y s i sSpecial-cause and common-cause variation.

Future trend: a lea r n i n go r g a n i z a t i o n

“One of our strengths isVa i sala’s long history of qualitywork related to the ISO 9001s y s t e m. This forms a good basisfor development work.” Mr.La u r i kainen continues: “It is achallenging task to change froma hierarchical to a process-o r i e n t-ed orga n i z a t i o n. ”

Wo r king with his team, heplans to apply system theory tothe exploration of the limitingfactors of processes. The overallgoal is to make a learning orga-nization a reality. “Looking tothe future, we have set highgoals for ourselves: We are striv-ing for a zero defect level. ” ■