Institut “Jožef Stefan” Ljubljana, Slovenija

IJS DP 9923

The ZeroOx Pest Control System in Slovene Ethnographic Museum

TEST REPORT

Location: Slovene Ethnographic Museum

Metelkova 2, 1000 Ljubljana, Slovenija

Bogomir Vrhovec, Institut Jožef Stefan Mag. Ana Motnikar, Slovene Ethnographic Museum

Dr. Leon Žlajpah, Institut Jožef Stefan

Ljubljana, May 2008

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TABLE OF CONTENTS 1 Introduction ............................................................................................................3

2 Container tightness.................................................................................................4

3 VPSA 6 nitrogen generator output PURITY...........................................................5

4 System turning over ................................................................................................5

5 First treatment with exhibits...................................................................................6 5.1 Treatment start........................................................................................................... 6 5.2 Changing of parameters during process .................................................................... 7 5.3 Pull-down times......................................................................................................... 8 5.4 End of tretment .......................................................................................................... 9 5.5 Observation after treatment ....................................................................................... 9

6 Remarks on ZeroOx software Unicool .................................................................10 6.1 Products previously programmed has dissapeared .................................................. 10 6.2 Refresh in Overview Containers is not active .................................................... 10 6.3 Parameters 4 and 20 do not accept all values .......................................................... 11 6.4 Measured O2 value shown on PC and processor are different ................................ 11 6.5 Measured values does not correspond settings in parameters 4 and 20................... 11

7 Conclusion ............................................................................................................12

8 Diagrams ..............................................................................................................13

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1 INTRODUCTION Test equipment:

• VPSA 6 ZeroOx Nitrogen generator, injection mode, including cabinet and noise insulation

• Control processor in separate cabinet, measuringand controlling oxygen content, relative humidity and temperature in container

• A personal computer with ZeroOx Unicool software • Calibration gas • Container equipped with:

- over/under pressure valve and ventilator with overpressure valve - air humidification unit - heater with fan - independent O2 sensor ICA 221 - micro manometer - Emergency stop switch for emergency shut down of the VPSA 6 nitrogen

generator VPSA 6 ZeroOx nitrogen generator, Control processor, personal computer, calibration gas end container equipment has been supplied by B-Cat, Biezenwei 6, 4004 MB Tiel, The Nederlands. On Museum’s special wish the air buffer has not been installed. Container is constructed from insolating panels:

• walls and ceiling: both side stainless steel insolating panels 100 mm thick, inner side painted with gas tight resin Isolcoat

• floor: reinforced concrete, painted with gas tight resin Isolcoat, protected my rubber 2 mm thickness and ribbed alluminum plates; edges rounded

• door: both side stainless steel insolating panels 100 mm thick, inner side painted with gas tight resin Isolcoat. Door sealing with Salco pattented inflatable sealing; on right side 3 hinges, on other sides 3 screws per side, manual tighting

Container has been supplied by Institut Zoran Rant, Kidričeva 66a, 4220 Škofja Loka, Slovenija. The system has been installed in October 2006.

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2 CONTAINER TIGHTNESS Criteria for container tightness defined by BCat is following:

• Container should be set to 10mm H2O column overpressure (10mmWC), measured by micro manometer

• Overpressure should not fall lower than 1 mm H2O column overpressure (1mmWC) within 30 minutes

First test showed that container tightness was far away from expected. During 2007 several measures has been taken to improve container tightness, as follows:

• Additional sealing of edges with silicone improved tightness, but not enough • Removing floor originally made of insolating panels, changing it with

reinforced concrete, painting walls, ceiling and floor with gastight resin Isolcoat showed that main problem lies in door tightness

• Changing original rubber door sealing with Salco inflatable sealing improved sealing, but the sealing has been escaping from sealing frame. Escaping has been caused by non original inflatable tube of the sealing

• Using original Salco tube prevents escaping but tightness has still not been satisfactory

• Replacing Salco rubber sealing, finishing corners according to Salco instructions using original glue which enables soft junctions finally caused that container fulfil tightness criteria. Figure 1 is showing both tightness criteria and final tightness in the container.

Figure 1: Container tightness

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3 VPSA 6 NITROGEN GENERATOR OUTPUT PURITY On delivery VPSA 6 nitrogen generator has been set to 0,1% remaining oxygen. When looking for container leakage regulating valve for lower output purity has been unintentional closed and than opened again. This caused different setting of lower output purity. To reset it special equipment was necessary. When the container tightness has been satisfactory lower output purity of the VPSA 6 nitrogen generator has been reset by BCat specialist to 0,03% remaining oxygen. VA COMBI ICA 17 Portable Oxygen & Carbon Dioxide Analyser has been used for measuring remaining oxygen concentration. The analyser has been previously calibrated in Netherlands on altitude above sea level. Since sensor is measuring partial Oxygen level which warries with altitude, calibration has been repeated in Ljubljana (altitude 300 meters). The calibration gas which is used for prozessor calibration has been used for calibration of the analyser (2,5% CO2, 97,5% N2). The Oxygen ZERO potentiometer did not need any adjustment while Oxygen SPAN potentiometer has been slyghtly readjusted.

4 SYSTEM TURNING OVER System has been turned over to Slovene Ethnographical Museum at March 5th, 2008 in presence of reperesentatives of

• Slovene Ethnographical Museum: Bojana Rogelj Škafar (director) and mag. Ana Motnikar

• Instute Jožef Stefan: dr. Leon Žlajpah, Miro Vrhovec Turning over has been assited by mr. B. Pleterski, representative of TŰV SŰD Industrie Service GMbH TŰV SŰD Sava d.o.o. He requested additional documents concerning ZeroOx system and also container. B-Cat, manufacturer of ZeroOx system has provided following documents:

• Certificate Oxygen measuring system • EG Declaration of conformity for machinery • Criteria for chamber tightness

Institut Zoran Rant, manufacturer of the chamber has provided following documents:

• Technical specifications of the chamber including cleaning instructions • Technical specifications of the Isolcoat gas tight coat inside the chamber

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5 FIRST TREATMENT WITH EXHIBITS During 2007 several pull down tests with empty container has been performed. However, due to chamber leakage requested concentration has newer been reached. In this period system has performed about 2.500 operating hours. After fulfiling tightness criteria of the chamber, reseting of the VPSA generator and system turning over, first treatment with the exibits from museum’s collection has started.

5.1 Treatment start Start date: 13.3.2008, 9:30 a.m. Objects:

• Southern Slavs costumes and other exhibits • Umbrellas • Easter eggs • Honey breads • Pillows • Sheepskin coat, shirt • Box from handy depot

Pests inside objects:

• Moth • Beetles from honey breads

Selected parameters:

• Treatment time: 10 days • Target value O2: < 0,1% O2 • RH: 50% • Temperature: 240C

Unicool settings:

• Product name: Predmeti • Target temperature: 240C • Target value O2: 0,03% • Target value RH: 50% • Time N2 inj/0.1% O2 15 min • dO2 start N2 inject 0,03% (we wanted to set 0,01% but software does not

accept that setting (see Chapter 6.3) • O2 limit pulldown: 1,5% • All other parameters have been left at default values

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Figure 2: Container with exibits

5.2 Changing of parameters during process During process some measured values could not reach target values. Therefore parameters have been changed: • March 20th: Temperature has been set to 240C, but did not go higher than

230C. Temperature in the hall was 180C. Parameters 43, 44 and 46 have been changed as follows: Parameter Description Before After

43 dT start heating.... 1.00C 0.10C 44 dT stop heating..... 1.00C 0.10C 46 Min idle aft heating 5:00ms 4:00ms

• March 20th: O2 concentration was swinging between 0,13% and 0,15%

(measured in Unicool - see Chapter 6.4.). VPSA was switching off and on. Reason for this was small difference between set and measured O2 value. Parameter 21 Time N2 inj / 0.1% O2 has been set to 15 minutes. As sampling period was 30 minutes, generator has been running 15 minutes after measurement, than stopped and waiting for next measurement. Parameter Description Before After

21 Time N2 inj /0.1% O2 15.00ms 59.00ms

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• March 26th: O2 concentration was swinging between 0,08% and 0,13% (mesured in Unicool - see Chapter 6.4.). Parameter 20: dO2 start N2 inject. has been changed to 0,00%

Parameter Description Before After

20 dO2 start N2 inject 0.03% 0,00% • March 28th: after Parameter 20 change the O2 concentration was swinging

between 0,05% and 0,08% (measured in Unicool - see Chapter 6.4.). That means that O2 concentration has been all the time below 0,01%.

At this point the VPSA generator was not running all the time. To discover the lower possible limit of O2 concentration inside container we have changed the generator from external control to manual and and manually switched it on. After running in manual mode for couple hours we realised that O2 concentration inside container was rising. We found out that the generator, when it was switched on manuall, produces nitrogen with higher O2 content (higher capacity of generator). We switched the generator to external control again.

• March 30th at 6:00: after changing the generator to external control again O2

concentration swing returned to 0,05% to 0,08%. This point has been chosen as start time for treatment.

5.3 Pull-down times

Relative time: Calculated

BCat Measured Ljubljana

From (%)

To (%)

Duration (hours)

Duration (hours)

21,0 5,0 4,8 4,5 5,0 1,5 9,6 7 1,5 0,1 19,2 1,5 0,5 20 0,5 0,1 30

Absolute time:

O2 value Calculated BCat

Measured Ljubljana

Report Lisboa1

21 0 0 0 5 4,8 4,5

1,5 14,4 11,5 0,5 28 31,5 33,5 0,1 33,6 61,5

For graphical presentation see diagram at the end (Chapter 8).

1 A disinfectation system for the University library, Universidade Nova de Lisboa, Test report, René Luyten, Eng. And Rob H. Veltman, Ph.D., November 2005

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5.4 End of tretment Treatment has been ended after 10 days, 10. 4.2008 at 9:00 a.m.

5.5 Observation after treatment After container ventilation and opening we found out that plastic packaging for Easter eggs have changed the shape and colour (Figure 3). Packaging used was common type used for packaging eggs in supermarkets. Although the shape has changed, eggs has not been damaged. Adhesive plastic tape which was wrapped arround package did not change. To discover efectivenes of anoxic treatment, a moth trap (Figure 4) has been inserted into chamber and door closed again. Moth trap consisted of a tablet composed from glue with pheromones which attracts male moths. Container has been left closed for a month, maintaining temperature and humidity at same level as during the treatment. When door has been opened again there has been any moth on the trap. Therefore we suppose that all the stadiums of moths has been killed.

Figure 3: Easter eggs packaging after the treatment

Figure 4: Moth trap

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6 REMARKS ON ZEROOX SOFTWARE UNICOOL Software originally installed did not allow seting of 0,03% O2 concentration. At same time (January 2008) as resetting the VPSA 6 generator has ben performed BCat specialist installed new version of firmware in the control processor and software running on PC, Unicool V 1.3.9.0. Following are remarks on Unicool V.1.3.9.0

6.1 Products previously programmed has dissapeared • Previously programmed products (“old products”) has disappeared from

window Settings Containers Container1 Product selection (click on the apple) while new products, created after software upgrade have been listed.

• But, old and new products have been listed in window Management Products.

• Inspecting old and new products with MS Notepad I have noticed that headers differs (differences are highlated with color):

Old products: [General] Names=?,?,testiranje6,? "Types=S879 V1.9,M02,S03;" Date.Created=03.12.2007 09:29:38 [S879 V1.9,M02,S03] Parts=Gascontroller,Gascontroller,Gasc ontrol ler,Gascontroller New products: [General] Names=?,?,testiranje9,? Types=S879 V2.1,M02,S03; Date.Created=28.01.2008 11:29:39 [S879 V2.1,M02,S03] Parts=S879 V2.1,S879 V2.1,S879 V2.1,S879 V2.1

• After changing headers in old products with header from new products, also

old products appear in Settings Containers Container1 Product selection window.

6.2 Refresh in Overview Containers is not active Refresh button in Overview Containers is in new software not higlited and therefore not active. In old version after changing product content of the Overview

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Containers window did not change. Operator had to click on the refresh button to see new settings. As mentioned in 1.3.9.0 version refresh button in Overview Containers is not higlited. Now operator has to close the window manually and open it once again to see new settings. Authors of test report suggest to B-Cat that in new software versions Overview Containers window should refresh automatically after data transfer from PC to processor.

6.3 Parameters 4 and 20 do not accept all values Parameters 4 (Target value O2) and parameter 20 (dO2 start N2 inject.) do not accept all values. Entering parameters on PC;

Inserted value and ENTER

Display in field after ENTER

Display on processor after data transfer

0.01 0,00 0.00 0.02 0.03 0.02 0.03 0.03 0.02 0.04 0.05 0.05 0.05 0.05 0.05 0.06 0.05 0.05 0.07 0.08 0.07

Entering parameters from keyboard on processor:

Inserted value and ENT

Display on processor after ENT

0.01 0.00 0.02 0.00 0.03 0.02 0.04 0.02 0.05 0.05 0.06 0.05 0.07 0.05 0.08 0.07

6.4 Measured O2 value shown on PC and processor are different

In part of test, where the O2 concentration in container readout

• On processor was swinging between 0,07 and 0,12% (only these two values) • On PC Overview window was swinging between 0,08 and 0,13% (only these

two values)

6.5 Measured values does not correspond settings in parameters 4 and 20

Parameter 4 Parameter 20 Measured O2 swing on PC

0,03% 0,03% 0,08 and 0,13 (VPSA is switching ON and OFF) 0,03% 0,00% 0,05 and 0,08 (VPSA is switching ON and OFF)

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7 CONCLUSION • As any mothes has been caught on the moth trap after the anoxic treatment we

suppose that all stadiums of moths has been killed. • The requested O2 concentration in container specified in tender (0,03% O2) has

not been attained what is probably caused by fact that air buffer has not been installed. Also, output of the generator has 0,03% O2 almost all the time except in the sistem switch over (changing from one carbon filter to another) thus the mean oxygen concentration at the output is slightly higher.

• Attained O2 concentration which swings from 0,05% to 0,08% is lower than in most experiments which could be found in the literature (0,1%).

• In future resistance of different materials to anoxic atmosphere should be discover to avoid damages of exhibits.

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8 DIAGRAMS

Pull down times

0

5

10

15

20

25

0 10 20 30 40 50 60 70

Time (hours)

% O

2 CalculatedMuseum LjubljnaMuseum Lisboa