« Etabulles » Water Level Gauge

Vancouver BC November 03, 2004 version: 5,0

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« Etabulles » Water Level Gauge« Etabulles » Water Level Gauge

Presented by:Presented by:

Mr Claude Bouchard, Metrology Technician and Instrumentation Team LeaderMr Claude Bouchard, Metrology Technician and Instrumentation Team LeaderMr Joël Maniez, Engineer and Chief for Dams Safety and Civil Works TerritoryMr Joël Maniez, Engineer and Chief for Dams Safety and Civil Works Territory

Direction - Production des CascadesDirection - Production des CascadesDams and Civil WorksDams and Civil Works

Shawinigan, QuebecShawinigan, Quebec

CEA Technologies inc. CEA Technologies inc. Vancouver, BC / November 3, 2004Vancouver, BC / November 3, 2004


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WATER LEVEL MEASUREMENTWATER LEVEL MEASUREMENT

* Water Level Gauge operating principles* Problems of the actual Water Level Gauges* Designing objectives of the new Water Level Gauge* Project stages* Commercial agreement and private partners* ÉTABULLES characteristics* ÉTABULLES parameters* Laboratory tests* Costs and savings* Conclusion* Questions and comments…!

Presentation contentsPresentation contents


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The Water Level Gauge measures the pressure of water using a submerged pneumatic tube (bubble tube principle).

The device must be able to correct electronically or via preprogammed computation methods all unforeseen

elements which may affect the accuracy of final readings.

Water Gauge operating principlesWater Gauge operating principles


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After consulting with experienced users, specific problems having most impact on the Water Level Gauge operation were found :

The global measure error is not known ;

Lack of means in order to find out the sensor deviation ;

Problems related to preventive corrective maintenance;

Important and costly repair delays because of remote and hardly accessible sites;

Lack of basic information on measuring devices;

Lack of overall Water Level Gauge characteristics ;

Problems of the actual Water Level GaugeProblems of the actual Water Level Gauge


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False level readings in several occasions :

- Unsure readings;

- Inaccurate readings;

- False alarms. Level readings are not validated for operation:

- Field validation difficult or impossible;

- Mostly obliged to double the Water Level Gauge No redundancy in reading measure :

false alarms = wrong decisions = costs

Problems of the actual Water Level Gauge (cont’d)Problems of the actual Water Level Gauge (cont’d)


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Variation in time of calibration factor ; Sensor deviation (offset) ; Erratic replacement of empty nitrogen cylinders :

- replacement difficult to foresee;

- Inherent travel. Electronic and mechanical components not in

accordance with operating conditions ; Etc..

Problems of the actual Water Level Gauge (cont’d)Problems of the actual Water Level Gauge (cont’d)


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CAPTEUR DE NIVEAUX HYDRIQUES

0,00

2,00

4,00

6,00

8,00

10,00

12,00

0,00 0,50 1,00 1,50 2,00 2,50 3,00

mV/V / mètre

Ple

ine

éch

elle

du

cap

teu

r (m

)

511,00

513,00

515,00

517,00

519,00

521,00

523,00

Niv

eau

de

l'eau

(m

)

Simulation Capteur d'origine


0,00

2,00

4,00

6,00

8,00

10,00

12,00

0,00 0,50 1,00 1,50 2,00 2,50 3,00

mV / mètreP

lein

e é

ch

ell

e d

u c

ap

teu

r (m

)

500,00

502,00

504,00

506,00

508,00

510,00

512,00

Niv

eau

de

l'eau

(m

)


Sensor deviationVariation in time of the

calibration factor


Examples of errors on a sensor curveExamples of errors on a sensor curve


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0,00

2,00

4,00

6,00

8,00

10,00

12,00

0,00 0,50 1,00 1,50 2,00 2,50 3,00

mV/V / mètre

Ple

ine

éch

elle

du

cap

teu

r (m

)

511,00

513,00

515,00

517,00

519,00

521,00

523,00

Niv

eau

de

l'eau

(m

)


Examples of errors on a sensor curveExamples of errors on a sensor curve


0,00

2,00

4,00

6,00

8,00

10,00

12,00

0,00 0,50 1,00 1,50 2,00 2,50 3,00

mV/V / mètre

Ple

ine

éch

elle

du

cap

teu

r (m

)511,00

513,00

515,00

517,00

519,00

521,00

523,00

Niv

eau

de

l'eau

(m

)


Deviation combined with calibration factor variation

Deviation combined with calibration factor (curve crossing)



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Accurate and reliable level readings ; Minimized maintenance costs ; Reducing installation and maintenance costs

for the reading device ; Adopt a « hardware & software » policy in

accordance to the techonology criteria of the 2000’s ;

An excellent price-quality ratio.

New Water Level Gauge design objectivesNew Water Level Gauge design objectives


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Water Level Gauge concept Water Level Gauge design In situ specifications In situ testing of two prototypes Preliminary report Laboratory tests (Université Laval) Reports on the in situ tests Reports on the laboratory tests Final report

Sept. 2001 - Sept. 2002

Sept. 2002 - Dec. 2004

Sept. 2002 - Dec. 2004

Oct. 2003 - May 2005

Sept. 2004 - Dec. 2004

Oct. 2004 - March 2005

Oct. 2004 - May 2005

Feb. 2005 - March 2005

Jan. 2005 - May 2005

Project stages Project stages


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Patent application and marketing agreementPatent application and marketing agreement

Main aspects of the patent application and marketing agreement of the water level gauge:

Hydro-Québec has applied for a patent for the « Étabulles » Water Level Gauge in more than 175 countries, including Japan;

Marketing agreements including royalties for future sales have been signed with two private ventures in Canada and Europe;

The intellectual propriety of Hydro-Québec was protected and recognized upon signing the partnership with the two firms taking part in the development of the new water level gauge;



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Commercial - Commercial - PartnersPartners

The research costs and design of the hardware as well as the development cost of the sophisticated new softwares now go from $ 500 000 $ to $ 600 000 for each partner.

The Water Level Gauge development costs were entirely paid by both firms, and Hydro-Québec is even not compelled to acquire the new device in the future.

Hydro-Québec has decided to allow the private companies to create the new device in order not to compete with small specialized companies in this field.

This new approach has many advantages but entails extensive project managing difficulties.



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ÉtabullesÉtabulles characteristicscharacteristics - - MeasureMeasure

Provide accurate, reliable and in situ validated water

level readings, at all times, in order to improve the water inflow management process;

Optimize maintenance and servicing costs, while avoiding useless travelling due to dubious measures which cannot be remotely checked;

Permanently ensure the automatic checking of the instrument anchoring points elevation. This new method allows for the correction, if required, of the initial anchoring points elevations.

New concepts were created in order to minimize potential error risks in the water level measure:



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Étabulles characteristics – Étabulles characteristics – Measure (cont’d)Measure (cont’d)

Automatically measure the water density parameter, in order to better evaluate the water column head pressure of a reservoir or a basin;

Create a redundancy for several individual measuring sites with a single measuring device equipped with a single communication system;

Totally guarantee the validity of the water level measure in order to increase the safety of the population as well as the safety of Hydro-Québec's personnel .

Reduce the number of doubled in situ physical installations; Etc.



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Étabulles characteristics - Étabulles characteristics - GeneralGeneral

The new device can measure a level based on a 1 to 4 tube-combination, installed at variable depths. This new method increases measure reliability, and can postpone servicing;

The device also uses two pressures sensors, a primary captor and a very accurate and stable in time secondary captor, ensure the provision of self-validated results;

Predetermined measures deviation are selected by users in order to permanently check measure validity. This new method operates both on primary and secondary pressure captors and on each reading provided by the four individual tubes.

New measure principles were used for the new Water level Gauge, in order to reduce the risk of an incoherent reading :



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Examples of reliability for the new deviceExamples of reliability for the new device

Grid differential

WLGWLG WLG

U S. D S.

DAM

DIKE

WLG

A large array of installations is now possible with the new Water Level Gauge. It is easy to imagine other cases adaptable to specific in situ conditions.



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Étabulles Characteristics - Étabulles Characteristics - PneumaticPneumatic

The instrument is equipped with an air compressor generating sufficient pressure in order to cover the entire measuring range. The primary aim of the new system is to reduce costs as well as risks linked to the handling of nitrogen cylinders.

An automatic presssure transfer device is placed between the compressor and an auxiliary nitrogen tank (smallest size) in order to deactivate the compressor in some specific cases, such as failure, weak batteries, extreme operating temperatures, etc.;

A manual device can also be used when the user decides to choose nitrogen tanks in order to generate the required pressure. Such situation should happen very seldom.

This new process will permanently ensure reliable water level readings, as well as improve maintenance and servicing management, while reducing their related costs ;



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All softwares were developed in order to efficiently manage all functions of the water level gauge. Additional care was applied to the visual aspect in order to provide the best man- machine interface.

Management and access to an extensive network of water level gauges throughout the province;

Password use within various menus; Multi-user management including various responsibility levels

based on the specific task of technical and administrative personnel; Real-time reading of instrument essential paramaters, such as:

levels, alarm thresholds, anchorage points differential, water density, etc.;

Device development using internationally known computer systems;

Computer support (Windows environment).

Étabulles characteristics - Étabulles characteristics - SoftwaresSoftwares


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WATER LEVEL MEASUREMENT WATER LEVEL MEASUREMENT

Bi-directional communication in order to exchange information about the measuring device: alarm thresholds, anchoring points validation, loss rate tests, real-time reading, historic event record, etc. This approach ensures at all times the total control of the device without requiring personnel travel;

Several RS-232 communication ports are provided in order to eliminate human handling errors;

A SDI-12 exit ensures a universal compatibility with acquisition systems or other measuring systems;

The instrument is equipped with a TCP-IP exit, which allows for the totally safe data distribution on Intranet and even Internet, in specific cases,

It can communicate with MSAT and GOES satellite systems. It must be underligned that the instrument directly adapt to these systems, and no electronic interface must be added.

Devices are equipped with new technologies in order to improve communication with one or several water level measurement sites located on the large territory under Hydro-Québec jurisdication.

Étabulles Characteristics - Étabulles Characteristics - CommunicationsCommunications


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Power supply status ; Battery status ; Internal temperature ; Air reserve status Sensor validity status ; Relative elevation ; Absolute elevation ; Elevation variation ; Relative level ;

Variation speed gradient ; Nitrogen tank pressure ; Compressor status ; Primary sensor calibration ; Secondary captor calibration ; Sensor validation (delta) ; Memory check ; Alarm threshold ; Etc..

Étabulles Parameters – Étabulles Parameters – Real timeReal time


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Version number ; Program Signature ; Positioning ; Location ; Site Identification ; Installation Date ; Maintenance Date ;

Dam name ; Technician name ; Self-diagnosis ; Date of last sample ; Min., max., delta alarm

thresholds ; No-operation time ; Etc..

Étabulles Parameters - Étabulles Parameters - GeneralGeneral


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Purging periods (hrs) ; Pressure of air reserve (linked to compressor) ; Nitrogen tanks pressure ; Compressor operating time ; Number of compressor operating cycles ; Compressor utilization factor ; Pneumatic system loss rate review ; Air reserve evaluation according to use; Etc..

Étabulles Parameters - Étabulles Parameters - PneumaticPneumatic


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Maximum threshold of operation level ; Minimum threshold of operation level ; Delta threshold of operation level ; Filtering time on readings ; Filtering threshold on readings ; Etc..

Étabulles Parameters – Étabulles Parameters – OperationOperation


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Operating temperature : –55 to 60° C; Operating Relative humidity : 100% ; Sustained vibrations for dams and powerstations ; Lightning and voltage overload protection ; Etc.

The selected electric, electronic, mechanical and pneumatic components must be in accordance with military specifications:

Étabulles parameters - Étabulles parameters - ComponentsComponents


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WATER LEVEL MEASUREMENT WATER LEVEL MEASUREMENT PicturesPictures


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Hydraulic laboratory tests will be completed in order to validate some hydraulic phenomena which could generate marked errors during a bubble water gauge operation.

Bubble water level gauges may react to: current velocity, temperature, water salt content, the effect of variable wave frequency and amplitude atmospheric pressure, anchor depth from water surface, and so forth.

Todate, very few tests have been completed and documented which clearly show errors linked to the various factors mentioned above. Manufacturers have the in-house required tools in order to accurately establish the characteristics of their products, but unfortunately, in situ installations show that the accuracy of the final readings can be largely affected by specific conditions.

The tests will innovate as far as bubbler systems are concerned. Results will eliminate present ambiguities between diverging opinions of experts in this field.

WATER LEVEL MEASUREMENT WATER LEVEL MEASUREMENT Hydraulic laboratory testsHydraulic laboratory tests


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Gauge calibration using a 10-meter water column. Measurements will be taken at several stages.

Checking water descent or rise rates within a fixed time-period. Rates vary between 1 mm & 3 m/hour;

Flow velocity tests in order to evaluate their influence upon readings, according to the location of tube measurement points. Velocity range will vary between 0,25 and 1,50 m/s;

Tests in a wave-basin. Equipped with a wave-generating device in order to determine the influence pressure could have on measure points, at different depths. Different wave frequency and amplitude simulations will be used to reproduce at a small scale the actual conditions of rivers and reservoirs;

Writing exhaustive reports on all tests, including a complete analysis of effects generated on different measuring devices in the abovementioned circumstances.

Université Laval was entrusted by Hydro-Québec with the hydraulic tests of the water level gauges, and a complete test protocol was designed by Hydro-Québec to that effect, aiming at :


Laboratory tests – Université LavalLaboratory tests – Université Laval


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In situ installation costsIn situ installation costs

The installation costs of a water level measuring site are often 15 to 20 times higher than the cost of buying a water level gauge.;

It is essential to have in situ facilities standardized based on similar situations. Personnel training costs and completion speed of a personnel intervention amply justify such standardization.

The quality of such facilities directly affects the final result of the water level reading and may have substantial adverse effects on communication reliability. It may require numerous personnel visits, the premature replacement of some very expensive equipments and even lead, in some cases, to severe injuries.

Measure reliability and maintenance cost reduction are largely a factor of the appropriate installation on site, in accordance to preestablished quality standards in this field.



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Costs related to preventive maintenance and breakage of water level gauges vary during a regular operating year. Generally, each measuring device requires :

* 2 to 4 yearly visits by a technician team. * Compulsory replacement of a nitrogen cylinder. * 1 to 2 yearly shortages (all types).. * Occasional visits in order to monitor readings validation.

Transportation costs to a specific site are also a very significant piece of information in this cost evaluation.It is therefore estimated that between $500 and $4 500 are required for the visit of a technician team on a water level measure site. The total average yearly costs go between $10 000 and $25 000.

Maintenance costsMaintenance costs


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Reliability as well as accuracy of water level gauges are essential ingredients for the production planning, safety of facilities, personnel and population.

Well-adapted in situ facilities, complete specifications as well as appropriate communication systems will reduce by 15 to 20%, approximately the installation cost – i.e. $11 000 to $30 000 savings by site and or by device.

Maintenance costs are also reduced. The reduced number of shortages as well as less maintenance will ensure $4 000 to $8 000 savings each year, by gauge.

Savings - MaintenanceSavings - Maintenance


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Given the added characteristics of the new Water Level Gauge and its technical performance, we firmly believe that we can very significantly improve the reliability of the whole device, while increasing the safety of structures and of the population.

ConclusionConclusion


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Questions and comments…!


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« Etabulles » Water Level Gauge