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 Etabulles  Water Level Gauge

• Presented by
• Mr Claude Bouchard, Metrology Technician and
  Instrumentation Team Leader
• Mr Joël Maniez, Engineer and Chief for Dams
  Safety and Civil Works Territory
• Direction - Production des Cascades
• Dams and Civil Works
• Shawinigan, Quebec
• CEA Technologies inc.
• Vancouver, BC / November 3, 2004

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WATER LEVEL MEASUREMENT
Presentation contents

• 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!

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WATER LEVEL MEASUREMENT
Water Gauge operating principles

• 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.

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WATER LEVEL MEASUREMENT
Problems of the actual Water Level Gauge

• 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

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WATER LEVEL MEASUREMENT
Problems of the actual Water Level Gauge (contd)

• 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

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WATER LEVEL MEASUREMENT
Problems of the actual Water Level Gauge (contd)

• 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..

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WATER LEVEL MEASUREMENT
Examples of errors on a sensor curve
Variation in time of the calibration factor
Sensor deviation
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WATER LEVEL MEASUREMENT
Examples of errors on a sensor curve
Deviation combined with calibration factor
variation
Deviation combined with calibration factor (curve
crossing)
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WATER LEVEL MEASUREMENT
New Water Level Gauge design objectives

• 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
  2000s
• An excellent price-quality ratio.

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WATER LEVEL MEASUREMENT
Project stages

• 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
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Patent application and marketing agreement
WATER LEVEL MEASUREMENT

• 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 - Partners
WATER LEVEL MEASUREMENT

• 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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Étabulles characteristics - Measure
WATER LEVEL MEASUREMENT
New concepts were created in order to minimize
potential error risks in the water level measure

• 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.

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Étabulles characteristics Measure (contd)
WATER LEVEL MEASUREMENT

• 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 - General
WATER LEVEL MEASUREMENT
New measure principles were used for the new
Water level Gauge, in order to reduce the risk of
an incoherent reading

• 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.

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Examples of reliability for the new device
WATER LEVEL MEASUREMENT
Grid differential
WLG
WLG
WLG
WLG
DAM DIKE
U S.
D S.
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 - Pneumatic
WATER LEVEL MEASUREMENT
This new process will permanently ensure reliable
water level readings, as well as improve
maintenance and servicing management, while
reducing their related costs

• 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.

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WATER LEVEL MEASUREMENT
Étabulles characteristics - Softwares

• 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).

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WATER LEVEL MEASUREMENT
Étabulles Characteristics - Communications
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.

• 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.

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WATER LEVEL MEASUREMENT
Étabulles Parameters Real time

• 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..

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WATER LEVEL MEASUREMENT
Étabulles Parameters - General

• 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..

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WATER LEVEL MEASUREMENT
Étabulles Parameters - Pneumatic

• 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..

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WATER LEVEL MEASUREMENT
Étabulles Parameters Operation

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

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WATER LEVEL MEASUREMENT
Étabulles parameters - Components
The selected electric, electronic, mechanical and
pneumatic components must be in accordance with
military specifications

• Operating temperature 55 to 60 C
• Operating Relative humidity 100
• Sustained vibrations for dams and powerstations
• Lightning and voltage overload protection
• Etc.

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WATER LEVEL MEASUREMENT
Pictures
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WATER LEVEL MEASUREMENT
Pictures
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WATER LEVEL MEASUREMENT
Pictures
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WATER LEVEL MEASUREMENT
Pictures
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WATER LEVEL MEASUREMENT
Hydraulic laboratory tests

• 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.

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WATER LEVEL MEASUREMENT
Laboratory tests Université Laval
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

• 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.

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In situ installation costs
WATER LEVEL MEASUREMENT
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.

• 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.

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WATER LEVEL MEASUREMENT
Maintenance costs

• 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.

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WATER LEVEL MEASUREMENT
Savings - Maintenance

• 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.

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WATER LEVEL MEASUREMENT
Conclusion
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.
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WATER LEVEL MEASUREMENT
Questions and comments!