MODERNIZATION OF THE WATER RESOURCES MANAGEMENT PROJECT (PROMMA) IN MEXICO

Gerencia del Servicio Meteorológico Nacional (GSMN)

Catalogue of Conventional Hydrometeorological Instruments and Automatic Stations

FINAL REPORT N° 18 Geneva, September 1999

PREPARED BY THE WORLD METEOROLOGICAL ORGANIZATION (WMO) UNDER THE FRAMEWORK OF THE COMISION NACIONAL DEL AGUA

COMISIÓN NACIONAL DEL AGUA

World Meteorological Organization

SUMMARY

PART A - CLIMATOLOGICAL SENSORS Rainfall measurement Raingauge Rainfall recorders Tipping bucket type Weighting type Float type

REF.A1.20 REF.A1.30 REF.A1.40

Meteorological parameters Stephenson screen (small model) Stephenson screen (large model)

REF.A2.10 REF.A2.20

Screen instruments Thermometer dry Thermometer maxima Thermometer minima Piche evaporimeter Psychrometer Thermograph Hygrograph Hygro-thermograph

REF.A1.10

REF.A2.11 REF.A2.12 REF.A2.13 REF.A2.14 REF.A2.15 REF.A2.21 REF.A2.22 REF.A2.23

Evaporation Class A evaporation pan Colorado evaporation pan

REF.A3.10 REF.A3.20

Wind instruments Anemograph

REF.A4.10

Barometers Aneroid barometer Mercury barometer Barograph

REF.A5.10 REF.A5.20 REF.A5.30

PART B- HYDROLOGICAL SENSORS HYDROMETRY Staff gauges Water level recorders (floats and encoders) Water level recorders (bubble system)

REF.B1.10 REF.B1.20 REF.B1.30

WATER QUALITY Water sampler Dissolved oxygen meter Dissolved oxygen, conductivity meter Salinity, Conductivity , Temperature meter Turbidity meter pH meter

REF.B2.10 REF.B2.20 REF.B2.30 REF.B2.40 REF.B2.50 REF.B2.60

PART C - TELEMETRIC STATIONS - DCPs Data loggers (one parameter) Water level (pressure sensors) Water level (bubble system) Rainfall recorder Data loggers (two parameters) Data Collecting Platforms (DCPs)

REF.C1.10 REF.C1.20 REF.C1.30 REF.C1.40 REF.C1.50

Water level sensors Capacitive transducer Piezoresistive transducer

REF.C1.11 REF.C1.12

Meteorological sensors Tipping bucket raingauge Air temperature Relative humidity Anemometer Vane Pyranometer Heliograph

REF.C1.31 REF.C1.51 REF.C1.52 REF.C1.53 REF.C1.54 REF.C1.55 REF.C1.56

Water quality Data transmission

REF.C1.57 REF.C1.58

PART D - DISCHARGE MEASUREMENT EQUIPMENT Current meters (horizontal axis) Pigmy type Standard type Current meters (vertical axis) Pigmy type Standard type

REF.D1.10 REF.D1.20 REF.D1.30 REF.D1.40

Current meter - Electromagnetic type

REF.D1.50

Ultrasonic measuring station Acoustic Doppler Current Profilers

REF.D2.10 REF.D2.20

Additional devices Rods Winches Sounding weights Cable-ways Counters

REF.D3.10 REF.D3.20 REF.D3.30 REF.D3.40 REF.D3.50

PART E - GROUND WATER EQUIPMENTS Gauge Data loggers

REF.E1.10 REF.E1.20

GENERAL The Catalog general presentation as a binder should allows in a very easy manner the updating of the equipment technical cards in relation with the technical specification developments for the existing devices, and the add of new cards for the new equipment, in following in this way the technology developments. The Catalog is subdivided in five parts corresponding to the three main data acquisition fields e.g. climatology, hydrology and discharge measurement and to the two main equipment types e.g. conventional and non conventional. A specific colour allows the easy identification of each part. A card of standard format described each equipment as follow : - General presentation - Measurement specifications - Conditions of use - Technical specifications - Photo Each equipment has a reference number as shown in the following examples : REF. A.2.10 - A : refers to the Guide part (A climatological sensors) - 2 : refers to the type of equipment in the concern part - 10 : refers to the equipment order number REF. A2.11 - A : refers to the Guide part (A climatological sensors) - 2 : refers to the type of equipment in the concern part - 11 : refers to the sub-equipment order number in the set of equipment In this case A2.11 refers to the dry thermometer which is part of the Stephenson screen referred A2.10.

WORLD METEOROLOGICAL ORGANIZATION

CATALOG OF TECHNICAL SPECIFICATIONS FOR HYDROLOGICAL EQUIPMENTS

RAINGAUGE REF. A1. 10 GENERAL The ordinary raingauge used for daily readings usually takes the form of a collector above a funnel leading into a receiver. The size of the opening of the collector is not really important, but an area of 200cm² to 400cm² will probably be found convenient. Raingauges for use at places where only weekly or monthly readings are taken should be similar in design to the type used for daily measurement, but with a receiver of larger capacity and stronger construction Storage gauges are used to measured total seasonal precipitation. These gauges consist of a collector above a funnel, leading into a receiver large enough to store the seasonal catch. MEASUREMENT SPECIFICATIONS Two methods are commonly used for measuring the precipitation caught in the gauge : a graduated measuring cylinder, and a graduated dip rod. A measuring cylinder should be made of clear glass with a low coefficient of expansion and should be clearly marked with the size of gauge for which it is to be used. Its diameter should not be more than about one-third of that of the rim of the gauge. The graduations should be finely engraved. In general, markings should be at 0.2 millimetre intervals with whole millimetre lines clearly indicated. CONDITIONS OF USE All gauges in any area or country should have comparable exposures, and the same siting criteria should be applied to all. The gauge should be exposed with its orifice being horizontal over ground level. The height of the gauge orifice above the ground should be as low as possible because the wind velocity increases with height, but it should be high enough to prevent splash from the ground. A standard height of one metre is recommended. When adequate conditions from the wind is not possible, individual objects should not be closer to the gauge than a distance equal to four times their height. TECHNICAL SPECIFICATIONS Ring collector with a sharp edge linked to a cone-shaped funnel with a sufficient slope to avoid splashing effects. Opening area : 200cm² to 400cm² Direct reading Related graduate glass Support stand for 1 meter elevation of the ring collector above ground level Metallic or plastic made

RAINFALL RECORDERS TIPPING BUCKET TYPE REF. A1. 20 GENERAL The principle of this type of recording gauge is very simple. A light metal container id divided into two compartments and is balanced in unstable equilibrium about a horizontal axis. The rain is led from a conventional collecting funnel into the uppermost compartment. As for the raingauge, the size of the opening of the collector is not really important, but a standard area of about 400cm² should probably found convenient. The main advantage of this type of instrument is that it can have an electronic pulse output and can be recorded at a distance or for simultaneous recording of rainfall and river stage on a water stage recorder. MEASUREMENT SPECIFICATIONS After a predetermined amount of rain has fallen, the bucket became unstable in its present position and tips over to its other position of rest. The compartments of the container are so shaped that the water can now flow out of the lower one and leave it empty. Meanwhile, the rain falls into the newly positioned upper compartment. The movement of the bucket, as it tips over, is used to operate a relay contact and produce a record that consists of discontinuous steps. The distance between each step represents the time taken for a pre6specified amount of rain to fall. For many hydrological purposes, in particular for heavy rainfall areas and flood warning systems, 0.5 to 1.0 millimetre buckets are satisfactory. CONDITIONS OF USE The same constraints of use than for the raingauges have to be applied to the rainfall recorders. TECHNICAL SPECIFICATIONS Ring collector with a sharp edge linked to a cone-shaped funnel with a sufficient slope to avoid splashing effects. Opening area : 200cm² to 1000 cm² Bucket volume : 20 ml (represents 0,5mm of rain for a 400cm² collector area) Frequency of chart record (indicate on order) : - drum recorder : daily, weekly, - strip chart : 2 weeks to monthly or more (paper speed selectable from 1à to 20mm/h) Stand housing

RAINFALL RECORDERS WEIGHTING TYPE REF.A1. 30 GENERAL In these instruments, the weight of a receiving can plus the precipitation accumulating in it is recorded continuously, either by means of a spring mechanism or with a system of balance weights. Thus all precipitation is recorded as it falls

MEASUREMENT SPECIFICATIONS This type of gauge normally has no provision for emptying itself, but by a system of levers, it is possible to make the pen traverse the chart any number of times. Theses gauges have to be designed to prevent excessive evaporation losses. The main utility of this type of instrument is in recording snow, hail, and mixtures of snow and rain. It does require that the solid precipitation be melted before it can be recorded.

CONDITIONS OF USE The same constraints of use than for the raingauges have to be applied to the rainfall recorders. TECHNICAL SPECIFICATIONS Ring collector with a sharp edge linked to a cone-shaped funnel with a sufficient slope to avoid splashing effects. Opening area : 200cm² Range intensity : 0 to 50 mm/min. Height of rain : 250 mm (standard) Frequency of chart record (indicate on order) : - drum recorder : daily, weekly, - strip chart : 2 weeks to monthly or more (paper speed selectable from 10 to 20mm/h) Stand housing.

RAINFALL RECORDERS FLOAT TYPE REF. A1. 40 GENERAL In this type of instrument, the rainfall is fed into a float chamber containing a light float. As the level of the water rises, the vertical movement of the float is transmitted, by a suitable mechanism, into the movement of the pen on the chart. By suitably adjusting the dimensions of the receiving funnel and the float chamber, any desired scale on the chart can be obtained.

MEASUREMENT SPECIFICATIONS To provide a record over a useful period (at least 24 hours is normally required) the float chamber has either to be very large, or some automatic means has to be provided for emptying the float chamber quickly whenever it becomes full. The pen then returns to the bottom of the chart. This is usually done with some sort of siphoning arrangement. The siphoning process should start fully at a definite time with no tendency for the water to dribble over, either at the beginning or at the end of the siphoning, which should not take longer than 15 seconds. CONDITIONS OF USE The same constraints of use than for the raingauges have to be applied to the rainfall recorders. In addition, it can be noted that, in sand wind or dusty areas, combined with humidity during the night for example, the rod of the float can be sometimes stuck at the entrance of the float chamber. To prevent this phenomenon, a regular cleaning of the apparatus has to be done. TECHNICAL SPECIFICATIONS Ring collector with a sharp edge linked to a cone-shaped funnel with a sufficient slope to avoid splashing effects. Opening area : 400cm² to 1000 cm² Range : 0 to 50 mm Emptying time of float chamber : 30 seconds Accuracy ± 1% Frequency of chart record (indicate on order) : - drum recorder : daily, weekly, - strip chart : 2 weeks to monthly or more (paper speed selectable from 10 to 20mm/h) Stand housing

STEPHENSON SCREEN (small model) REF. A2. 10 GENERAL The screen is mainly conceived for the equilibrium between the inside air temperature and the outside air temperature, and the instruments protection against the direct or diffuse solar radiation. Screens (small or large models) are made of solid wood. The Stephenson screen (small model) generally sheltered the following instruments : - maxima thermometer (horizontally at the top) - dry thermometer (horizontally in the middle) - minima thermometer (horizontally and down) - wet thermometer (vertically in the right side) - Piche evaporimeter (vertically in the left side) or

- a thermo-hygrograph

MEASUREMENT SPECIFICATIONS The door of the screen should open to the North, the feet have to be strongly fixed in the soil. The middle of the screen should be at a height of about 1,50 meter above ground level. CONDITIONS OF USE The screen has to be installed in a lawn place, at a distance of fences, buildings, trees, etc to avoid any reflexion of surrounding objects and soil to the instruments. TECHNICAL SPECIFICATIONS Made of solid wood, painted in white, with a double roof made of steel or sometimes plastic. Inside dimensions : 49 x 49 x 45 cm (L x l x h) Option : support stand and stairs

STEPHENSON SCREEN ( large model) REF. A2. 20 GENERAL The Stephenson screen (large model) generally sheltered the following instruments : - maxima thermometer (horizontally on the right side) - minima thermometer (horizontally on the left side) - a psychrometer and a Piche evaporimeter (vertically in the middle) - - a thermograph (on the left side) - a hygrograph (on the right side)

MEASUREMENT SPECIFICATIONS The door of the screen should open to the North, the feet have to be strongly fixed in the soil. The middle of the screen should be at a height of about 1,50 meter above ground level. CONDITIONS OF USE The screen has to be installed in a lawn place, at a distance of fences, buildings, trees, etc to avoid any reflexion of surrounding objects and soil to the instruments. TECHNICAL SPECIFICATIONS Made of solid wood, painted in white, with a double roof made of steel or sometimes plastic. Inside dimensions : 110 x 50 x 65 cm (L x l x h) Option : support stand and stairs.

SCREEN INSTRUMENTS DRY THERMOMETER REF A2. 11 GENERAL Designed for the measurement of air temperature inside a screen. Principle : Apparent expansion of the mercury in the tube relating to the temperature.

TECHNICAL SPECIFICATIONS Mercury thermometer Range (tropical type) : -11°C to 71°C

SCREEN INSTRUMENTS MAXIMA THERMOMETER REF. A2. 12 GENERAL MAXIMA THERMOMETER Designed for the measurement of air maximum temperature inside a screen. The range is generally from -11°C to 71°C (for the tropical type). Principle : For an increasing temperature, the mercury cross a bottleneck at the top of the bulb, for a decreasing temperature this bottleneck avoid the mercury to go back to the bulb.

TECHNICAL SPECIFICATIONS Mercury thermometer Range (tropical type) : -11°C to 71°C

SCREEN INSTRUMENTS MINIMA THERMOMETER REF A2. 13 GENERAL Designed for the measurement of air minimum temperature inside a screen.

Principle : The index pushed by the toluene column for increasing temperature is stopped for decreasing temperature. The minimum temperature reading is done at the top extremity of the index.

TECHNICAL SPECIFICATIONS Toluene column thermometer The range is generally from -26°C to 61°C (for the tropical type).

SCREEN INSTRUMENTS PICHE EVAPORIMETER REF. A2. 14 GENERAL Designed for the measurement of evaporation inside a screen. Principle : The free area of the paper ring at the bottom of the pipe is considered as the evaporating area. The pipe is directly graduated in mm and 1/10 mm of evaporated water.

TECHNICAL SPECIFICATIONS Glass measuring tube with hanging ring : L = 300mm ; Φ = 14 mm ; complete with evaporation paper discs Φ = 30 mm, thickness = 0.5 mm and holder. Glass tube graduated each 1/10 mm

SCREEN INSTRUMENTS PSYCHROMETER REF. A2. 15 GENERAL Designed for the measurement of vapour pressure, air relative humidity and dew point.

Principle : Measure of the T temperature of the dry bulb and T’ temperature of the wet bulb, and calculation of relative humidity from tables.

TECHNICAL SPECIFICATIONS Metallic mounting fixed at the end of a handle and supporting two thermometers (dry and wet) Technical specifications of the thermometers

SCREEN INSTRUMENTS THERMOGRAPH REF. A2. 21 GENERAL Designed for the record of air temperature, time spotting of daily maximum and minimum, and study of temperature variations relating to front crossings. MEASUREMENT SPECIFICATIONS The sensitive element is generally made of an ultrasensitive bi-metallic element mounted straight without welding and secured in such a manner that it is not submitted to heat radiations of the housing, adjustment screw. TECHNICAL SPECIFICATIONS Temperature range : from -15°C to 65°C Accuracy : ± 1% of the full scale. For the ordering, the rotation drum has to be specified : 24 hours, 7 days, or other. NOTE : This instrument could be designed in a single one with a hygrograph. The record of the two curves on a single diagram is very useful for the relationship study of the two parameters : temperature and humidity.

SCREEN INSTRUMENTS HYGROGRAPH REF. A2. 22 GENERAL Designed for the record of the relative humidity and time spotting of maximum and minimum relative humidity values. MEASUREMENT SPECIFICATIONS The sensitive element is generally made of a double bundle of human hairs mounted on a crossbar suspension allowing a perfect equilibrium between the two bundles. TECHNICAL SPECIFICATIONS Range humidity : 20% to 100% Accuracy : ± 3% of relative humidity For the ordering, the rotation drum has to be specified : 24 hours, 7 days, or other. NOTE : This instrument could be designed in a single one with a thermograph. The record of the two curves on a single diagram is very useful for the relationship study of the two parameters : temperature and humidity.

SCREEN INSTRUMENTS HYGRO-THERMOGRAPH REF. A2. 23 GENERAL Designed for the record of the relative humidity and time spotting of maximum and minimum relative humidity values as well as air temperature. MEASUREMENT SPECIFICATIONS The humidity sensitive element is generally made of a double bundle of human hairs mounted on a crossbar suspension allowing a perfect equilibrium between the two bundles. The air temperature element is made of an ultrasensitive bi-metallic element mounted straight without welding and secured in such a manner that it is not submitted to heat radiations of the housing, adjustment screw. TECHNICAL SPECIFICATIONS Humidity range : 20% to 100% Accuracy : ± 3% of relative humidity For the ordering, the rotation drum has to be specified : 24 hours, 7 days, or other. Temperature range : from -15°C to 65°C Accuracy : ± 1% of the full scale. For the ordering, the rotation drum has to be specified : 24 hours, 7 days, or other.

EVAPORATION CLASS A EVAPORATION PAN REF. A3. 10 GENERAL The US class A pan was recommended by WMO and IAHS as a reference instrument. Its performance has been studied under a range of climatic conditions within wide limits of latitude and elevation.

Several types of automatic evaporation pan are in use. The water level in the pan is kept automatically constant, and the amount of water added to or removed from the pan is recorded.

MEASUREMENT SPECIFICATIONS The water level in the pan must be measured accurately before and after water is added. The water level may be determined by means of a hook gauge consisting of a movable scale and vernier fitted with a hook enclosed in a steel-water chamber in the pan. The depth of the water in the pan should be maintained between 17,5cm and 20 cm. CONDITIONS OF USE The class A evaporation pan is mounted above the ground on a wood floor. The site of the pan should be reasonably level and free from obstruction. At sites where normal climate and soil do not permit the maintenance of soil cover, the ground cover should be maintained as near as possible to the natural cover common in the area. Obstructions such as trees, buildings, shrubs, or instrument shelters should not be closer than four times the height of the object above the pan. The minimum size of the plot should be 15 by 20 metres. A wire-mesh screen of standard design should be installed over the pan to prevent animals from drinking the water. Daily evaporation is computed as the difference in water level in the pan on successive days, corrected for any precipitation during the period. The amount of evaporation that has occurred between two observations of water level in the pan is determined by : E = P ± ∆d where P is the depth of precipitation during the period between the two measurements, and ∆ is the depth of water added (+) to or removed (-) from the pan. TECHNICAL SPECIFICATIONS It is generally made of stainless steel, circular shape with a diameter of 121,9cm and a depth of 25,4cm. The pan should be equipped with a hook gauge evaporimeter enclosed in a steel-water chamber for accurate reading of the water variations in the pan. The class A evaporation pan should be installed on a duckboard at about 15 cm above the ground level.

EVAPORATION COLORADO PAN

REF. A3. 20 GENERAL It has the shape of a parallelepiped, the section is a square of 0.914 m length, the depth is of 0.426 m. It is buried in the soil in such a way that the upper edges have to be 10 cm above the ground level. The water level in the pan is maintained closely to the ground level. The advantage is that the buried pans are less sensitive to the temperature variations and to side effect due to solar radiation. MEASUREMENT SPECIFICATIONS The water level in the pan must be measured accurately before and after water is added. The water level may be determined by means of a hook gauge consisting of a movable scale and vernier fitted with a hook enclose in a steel-water chamber in the pan. CONDITIONS OF USE The site of the pan should be reasonably level and free from obstruction. At sites where normal climate and soil do not permit the maintenance of soil cover, the ground cover should be maintained as near as possible to the natural cover common in the area. Obstructions such as trees, buildings, shrubs, or instrument shelters should not be closer than four times the height of the object above the pan. The minimum size of the plot should be 15 by 20 metres. A wire-mesh screen of standard design should be installed over the pan to prevent animals from drinking the water. Daily evaporation is computed as the difference in water level in the pan on successive days, corrected for any precipitation during the period. The amount of evaporation that has occurred between two observations of water level in the pan is determined by : E = P ± ∆d where P is the depth of precipitation during the period between the two measurements, and ∆ is the depth of water added (+) to or removed (-) from the pan. TECHNICAL SPECIFICATIONS It is generally made of galvanized iron or sheet steel painted in grey, square shape of 0.914 m length, the depth is of 0.426 m. The depth of the water in the pan should be maintained closed to the ground level. The pan should be equipped with a hook gauge evaporimeter enclosed in a steel-water chamber for accurate reading of the water variations in the pan.

WIND MEASUREMENT ANEMOGRAPH REF. A4. 10 ANEMOMETER GENERAL The most common is the three-cup rotor or fan anemometer. It should be installed at the top of a two metres height pole. MEASUREMENT SPECIFICATIONS Accuracy of wind measurements by the three-cup or fan anemometers is usually within ± 0.5m.s-1, which is considered acceptable for evaporation measurements. TECHNICAL SPECIFICATIONS Range : 0.3 to 50 or 60 m.s-1 Accuracy : 0.5 m.s-1 Threshold : 0.2 m.s-1 VANE GENERAL Designed for recording wind directions. MEASUREMENT SPECIFICATIONS The vane should be installed in such a way that it indicates the direction from where the wind is blowing. TECHNICAL SPECIFICATION Scale : O to 360 Accuracy : 5° Threshold : 0.5 Frequency of chart record (indicate on order) : - drum recorder : daily, weekly, - strip chart : 2 weeks to monthly or more (paper speed selectable from 10 to 20mm/h) The anemometer and vane are generally mounted in a single apparatus, with a strip chart recorder.

BAROMETERS ANEROID BAROMETER REF. A5. 10 GENERAL Designed for the atmospheric pressure measurement. Direct readings without correction. Principle : elastic bending amplifying of the barometric sensor relating to the atmospheric pressure variations. TECHNICAL SPECIFICATIONS Thermical correction by a bi-metallic element between -10°C and 50°C. Atmospheric pressure range : 900 hPa to 1050 hPa Accuracy : ± 1hPa. .

BAROMETERS MERCURY BAROMETER REF. A5. 20 GENERAL Design for the atmospheric pressure measurement. This type of barometer should be installed inside a building. Principle : equilibrium of forces pressure exercise above a mercury free surface by the atmospheric air column and by the mercury column of the barometer. MEASUREMENT SPECIFICATIONS The barometer must be located in a very low or slow temperature variations room. The barometer place has to be protected against direct solar radiation, radiation due to system heating and draught vibrations. TECHNICAL SPECIFICATIONS Measurement range : 790 to 1070 hPa Accuracy : ± 0,25 hPa Glass barometric pipe Thermometer graduated each 0.5°C Scale in hPa, 1/20 vernier Component elements : bowl mercury, glass barometric pipe, thermometer plunging in a mercury bottle, small board.

BAROGRAPH REF. A5. 30 GENERAL Designed for the atmospheric pressure measurement. Principle : elastic bending amplifying of the barometric sensor relating to the atmospheric pressure variations. TECHNICAL SPECIFICATIONS Thermical correction by a bi-metallic element between -10°C and 50°C. Atmospheric pressure range : 900 hPa to 1050 hPa Accuracy : ± 1hPa. Record on a daily or weekly drum chart.

HYDROMETRY STAFF GAUGES REF. B1. 10 GENERAL The staff gauges allowed the direct reading of water levels by an observer and the record accuracy check of water level recorders. Generally made of enamel steel, they are graduated for centimetric readings. Two main types of staff gauges : 1) with the metric and decimetric values engraved on each unit, 2) with the decimetric values engraved on the units, but the metric values engraved on separate small plates which have to be fixed on the staff gauge units.

MEASUREMENT SPECIFICATIONS The staff gauges have to be fixed vertically against bridge embankments or piers, or against strong steel bars stuck in the ground. The successive staff gauge units should be correctly levelled to allow accurate water level readings without « blank » or overlapping. TECHNICAL SPECIFICATIONS Made of enamel steel, clearly graduated each centimetre.

HYDROMETRY WATER LEVEL RECORDERS FLOAT TYPE (ENCODERS) REF. B1 .20 GENERAL An encoder allows the modernisation of former float water level recorders for the digitalization of the measured values in situ. The encoder is generally coupled to the pulley of the recorder, and the measured analog values are converted in digital recording. The signal output can be as BCD, BINARY or GRAY code. Data recording can be done simultaneously on digital way and on a conventional paper chart.

MEASUREMENT SPECIFICATIONS The encoder are used for driving the same cable as well as the same float of the recorder. The measuring range is generally at least of 100 m, the resolution of 0.01% for a 10 m range. CONDITIONS OF USE The conditions of use are the same as for the conventional water level recorders. TECHNICAL SPECIFICATIONS Measuring range : 0 to 100 m Accuracy/resolution : measured value in cm Adequate friction clutch Specify desired direction (sense of rotation : left-hand rising or right-hand rising facing the display) Power supply : internal battery Memory storage capacity : 32 K

HYDROMETRY WATER LEVEL RECORDERS BUBBLE SYSTEM REF. B1. 30 GENERAL The water level recorder using bubble system has been designed for the measurement and recording of water levels at sites where the use of conventional float-operated recorders is not recommendable, e.g. elongated flat-inclined slopes on rocky bottom and or banks ..... Below the lowest water level to be measured there is the orifice of the measuring tube (air hose). Gas (generally compressed air) is continuously supplied by means of a compressed air bottle, internal or external compressor. The gas flows into the measuring tube and evenly bubbles out into the water. Data recording on strip chart and/or data logger. MEASUREMENT SPECIFICATIONS Depending on the height of water level (h) above the point of orifice, a gas pressure is produced in the measuring tube of a magnitude equal to the hydrostatic pressure (p) : p=ρ.h

(ρ = specific gravity of water).

Different measuring ranges are possible, mainly : 0-2.5 m ; 0-5 m ; 0-10 m ; 0-20 m. The accuracy is of about 1 cm for 10 m measuring range. CONDITIONS OF USE Generally the permissible flow velocity at the bubbling orifice is of 3 m.s-1 , and the maximum rate of water level change of 25 cm/mn. The maximum length of the measuring tube is 300 metres. Power supply by storage battery 12V and solar panel. TECHNICAL SPECIFICATIONS Measuring range : 0 to 10 m.(with internal compressor) 0 to 20 m (with external compressor) Accuracy 1% of the scale Temperature deviation : ± 0,2% of the scale Temperature range : - 20°C to 60°C Measuring period : from 1 mn to 99 mn. Bleeding period : from hourly to... Capillary tube : length to be defined

WATER QUALITY WATER SAMPLER (for suspended sediments) REF. B2. 10 GENERAL Design for water sampling in rivers, tanks, lakes etc. Most of the water samplers have a programming function for the time of sampling, the sampler volumes etc.

MEASUREMENT SPECIFICATIONS The programming function should permit to define : - the starting time relating to water depth or discharge - the sampler volumes - the number of samplers and the samplers distribution relating to the gradient range

CONDITIONS OF USE

TECHNICAL SPECIFICATIONS Number of bottles e.g. 24 bottles of 1liter or 12 bottles of 2 liters, or 6 bottles of 5 liters. Bottles material : glass or polyethylene Type of pump : vacuum or peristaltic Sampling frequency : from 30 sec to 1 hour or automatic control relating to range variations Power supply : external battery

WATER QUALITY (handhold instrument) DISSOLVED OXYGEN REF. B2. 20 GENERAL Design for dissolved oxygen measurement in the field. Normally with a built-in calibration chamber and direct salinity compensation.

TECHNICAL SPECIFICATIONS Accuracy :

Range : Resolution :

mg/L : ± 0.3 %air : ± 2% Temperature : ± 0.4°C mg/L : 0 - 20 %air : 0 - 200% Temperature : -5 to + 45°C mg/L : 0.01 %air 0.1% Temperature : 0.1°C

Power supply : battery Salinity compensation Temperature compensation

WATER QUALITY (Handhold instrument) DISSOLVED OXYGEN + CONDUCTIVITY meter REF. B2. 30 GENERAL Design for simultaneous measurements of dissolved oxygen, conductivity and temperature in the field.

TECHNICAL SPECIFICATIONS DISSOLVED OXYGEN

CONDUCTIVITY

Accuracy :

mg/L : ± 0.3 %air : ± 2% Temperature : ± 0.4°C

Accuracy :

conductance salinity : temperature :

± 0.5% full scale ± 2% or 0.1 PPT ± 0.1°C

Range :

mg/L : 0 - 20 %air : 0 - 200% Temperature : -5 to + 45°C

Range :

conductance salinity : temperature :

0 to 200 mS 0 to 80 PPT -5 to +65°C

Resolution :

mg/L : 0.01 %air 0.1% Temperature : 0.1°C

Resolution :

conductance : salinity : temperature :

0.1µS 0.1 PPT 0.1°C

Power supply : battery Salinity compensation Temperature compensation

Power supply : battery Temperature compensation

WATER QUALITY (Handheld instrument) SALINITY + CONDUCTIVITY+ TEMPERATURE meter REF. B2. 40 GENERAL Design for simultaneous measurements of the three parameters : salinity, conductivity and temperature.

TECHNICAL SPECIFICATIONS Accuracy :

conductance salinity : temperature :

± 0.5% full scale ± 2% or 0.1 PPT ± 0.1°C

Range :

conductance salinity : temperature :

0 to 200 mS 0 to 80 PPT -5 to +65°C

Resolution :

conductance : salinity : temperature :

0.1µS 0.1 PPT 0.1°C

Power supply : battery Temperature compensation

WATER QUALITY (Handheld instrument) TURBIDITY meter REF. B2. 50 GENERAL Design for simultaneous measurements of turbidity and temperature.

TECHNICAL SPECIFICATIONS Accuracy :

turbidity ± 5% temperature ± 0.1°C

Range :

turbidity 0 to 2000 NTU temperature -5 to 60°C

Resolution :

turbidity 0.1 temperature 0.1°C

Power supply : battery Temperature compensation

WATER QUALITY (handheld instrument) pH meter REF. B2. 60 GENERAL Design for pH measurements in rivers, lakes etc.

TECHNICAL SPECIFICATIONS Accuracy :

± 0.1 unit

Range :

0 to 14 units

Resolution :

0.01 unit

Power supply : battery temperature compensation

DATA LOGGERS WATER LEVELS (pressure sensors) REF. C1. 10 GENERAL These data loggers are designed for the acquisition and recording of water levels measured by a sensor. The water temperature is generally displayed on the terminal. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger.

MEASUREMENT SPECIFICATIONS Adjustable spent time and minimum change in range should be available (example from 01 to 99 mn and from 01 to 99 cm) for data storage and optimisation of memory capacity. The memory capacity must allow an autonomy of few months, according with the variations in water levels. CONDITIONS OF USE For the data logger with capacitive sensor the limitation distance to the sensor is of about 1000m. This type of data logger can be connected with a satellite transmitter, or telephone MODEM, or radio. TECHNICAL SPECIFICATIONS Input : Output :

limnimetric sensor RS 232C for connection of a specific device as initialization terminal, or laptop computer, or satellite transmitter, MODEM..... from -20° to + 70°C ; humidity : 100% by initializable real time clock, drift less than one minute a month. by internal battery or external battery and solar panel.

Climatic conditions : Calendar time base : Power supply : Waterproof connections In their basic configuration, the data loggers must be equipped with sensors for housekeeping variables (inside temperature, battery voltage and charge, status of the data storage memory). In option housing and/or field installation equipment (as a tower for flooding areas) should be proposed. Complete with sensor : REF. C1.11 or REF. C1.12

DATA LOGGERS WATER LEVELS (bubble system) REF. C1. 20 GENERAL These data loggers are designed for the acquisition and recording of water levels in rivers, lakes, dams etc.. The water temperature is generally displayed on the terminal. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger.

MEASUREMENT SPECIFICATIONS Due to an internal mini air-compressor, the water level measurement is carried out through the pressure measurement of a low air discharge injection at the sensor level. This pressure is applied to a silicium diaphragm which gives a signal related to the water depth Adjustable spent time and minimum change in range should be available (example from 01 to 99 mn and from 01 to 99 cm) for data storage and optimisation of memory capacity. The memory capacity must allow an autonomy of few months, according with the variations in water levels. CONDITIONS OF USE For the bubble system data logger the conditions of use are the same as for the conventional one. This type of data logger can be connected with a satellite transmitter, or telephone MODEM, or radio. TECHNICAL SPECIFICATIONS Output :

Input : limnimetric sensor RS 232C for connection of a specific device as initialization terminal, or laptop computer, or satellite transmitter, MODEM..... from -20° to + 70°C ; humidity : 100% by initializable real time clock, drift less than one minute a month. by internal battery or external battery and solar panel.

Climatic conditions : Calendar time base : Power supply : Waterproof connections In their basic configuration, the data loggers must be equipped with sensors for housekeeping variables (inside temperature, battery voltage and charge, status of the data storage memory). In option housing and/or field installation equipment (as a tower for flooding areas) should be proposed.

DATA LOGGERS RAINFALL RECORDER REF. C1. 30 GENERAL These data loggers are designed for the acquisition and recording of rainfall measured by a tipping bucket raingauge fitted with a switch. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger. MEASUREMENT SPECIFICATIONS For a convenient record, each tipping must be dated in hours, minutes and seconds, the years, months and days changing automatically from the calendar clock. The memory capacity must allow an autonomy of few months, according with the rainfall amount and the area of the raingauge collector. CONDITIONS OF USE All gauges in any area or country should have comparable exposures, and the same siting criteria should be applied to all. The gauge should be exposed with its orifice being horizontal over ground level. The height of the gauge orifice above the ground should be as low as possible because the wind velocity increases with height, but it should be high enough to prevent splash from the ground. A standard height of one metre is recommended. When adequate conditions from the wind is not possible, individual objects should not be closer to the gauge than a distance equal to four times their height. TECHNICAL SPECIFICATIONS Input : Output :

1 channel +5v active pulsed signal RS 232C for connection of a specific device as initialization terminal, or laptop computer, or satellite transmitter, MODEM..... from -20° to + 70°C ; humidity : 100% initializable real time clock, drift less than one minute a month. by internal battery or external battery and solar panel.

Climatic conditions : Calendar time base : Power supply / Waterproof connections In their basic configuration, the data loggers must be equipped with sensors for housekeeping variables (inside temperature, battery voltage and charge, status of the data storage memory). Complete with sensor : REF. C1.13

DATA LOGGERS TWO PARAMETERS REF. C1. 40 GENERAL The two parameter data loggers are generally designed for the acquisition and recording of water levels and rainfall. The water temperature is generally displayed on the terminal. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger. The data logger has to be connected simultaneously to a pressure sensor for water levels and to a tipping bucket rainfall gauge fitted with a switch.

MEASUREMENT SPECIFICATIONS For water levels : Adjustable spent time and minimum change in range are available (example from 01 to 99 mn and from 01 to 99 cm) for data storage and optimisation of memory capacity. The memory capacity must allow an autonomy of few months, according with the variations in water levels, power supply by internal battery or external battery and solar panel. For rainfall : The logger has to record systematically the date and time of each pulse generated by the tipping bucket gauge. Each tipping should be dated in hours, minutes and seconds, (years, months and days changing automatically). According to the surface area of the gauge, the memory capacity must allow the record of few metres of rain. CONDITIONS OF USE For the data logger with capacitive sensor the limitation distance to the sensor is of about 1000m. This type of data logger can be connected with a satellite transmitter, or telephone MODEM, or radio. TECHNICAL SPECIFICATIONS Input :

-1 channel for limnimetric sensor - 1 channel +5v active pulse signal filtered and memorized by software RS 232C for connection of a specific device as initialization terminal, or laptop or satellite transmitter, MODEM..... from - 20° to + 70°C ; humidity : 100% by initializable real time clock, drift less than one minute a month. by internal battery or external battery and solar panel.

Output : computer, Climatic conditions : Calendar time base : Power supply : Waterproof connections In their basic configuration, the data loggers must be equipped with sensors for housekeeping variables (inside temperature, battery voltage and charge, status of the data storage memory). In option housing and/or field installation equipment should be proposed. Complete with sensors : REF. C1.11 or REF. C1.12 and REF. C1.13

DATA COLLECTING PLATFORMS (DCPs) MULTI-PARAMETERS REF. C1. 50 GENERAL The DCPs are designed for the acquisition and management of hydrometeorological data. Their architecture must allow at any time the connection of a lot of sensors ( generally about 15 sensors), the whole set or part of them, as : water level, water quality parameters: Ph, conductivity, temperature, dissolved oxygen, turbidity, ... meteorological parameters: rainfall, temperature, humidity, wind (speed and direction), solar radiation,.... in an easy way which don’t need a return to the manufacturer

MEASUREMENT SPECIFICATIONS The data acquisitions have to be made at fixed or programmable intervals for the synchronous sensors, and instantaneously for asynchronous sensors (e.g. rainfall recorders). The memory storage capacity should be of at least 2 Mb. The DCPs must generally include a set of internal measurement inputs for calibration and checking of the system as : measurement of internal temperature, battery voltage, solar panel voltage, status of available memory,.... CONDITIONS OF USE The conditions of use are the same as for the data loggers and mainly defined by the sensors conditions of use. The DCPs can be connected with a satellite transmitter, or telephone MODEM, or radio. TECHNICAL SPECIFICATIONS Generally the data are received as direct measurements (analog to digital converters, counters, frequency meters, ...) or as indirect data (RS 232 serial link,...). So, the list of acquisition inputs enabling external sensors to be connected to the DCP should be approximately as follow : 9 analog inputs for voltage measurements 3 pulse counter inputs, including one with analog anti-bounce cell (for rainfall). 2 frequency measurement inputs 4 multiplexed serial link inputs 8 dry contact logic acquisition inputs 1 BCD/GRAY 16-bit parallel input Climatic conditions : from -20° to + 70°C ; humidity : 100% Calendar time base : by initializable real time clock, drift less than one minute a month. Power supply : by internal battery or external battery and solar panel. Waterproof connections Complete with sensors : C1.11 or C1.12 AND C1.13 + C1.51 to C1.57 as needed

WATER LEVEL SENSORS CAPACITIVE TRANSDUCER REF. C1. 11 GENERAL The water level is measured by a pressure transducer providing an electrical output proportional to the hydrostatic pressure of liquid related to the atmospheric pressure. The sensor is generally constituted of a substrate and a ceramic diaphragm. The sensor is connected to the data logger with a specific cable.

MEASUREMENT SPECIFICATIONS The sensor measured both water level and temperature. Transmission to the logger is of true binary type through a low speed (100 bits/sec) synchronous serial transmission allowing « long distance » communications. CONDITIONS OF USE The sensor has to be strongly fixed at the bottom or at a defined level in the river bed, linked to the data logger through the connecting cable. This one should be protected in its submerged part as well as in its aerial part against damages. Normally with this type of device the distance between the sensor and the logger can be more than 1 km. TECHNICAL SPECIFICATIONS Range of measurement : Temporary over pressure : Accuracy : Working temperature : Tracking speed : Acquisition time : Supply consumption :

0 to 10 m. minimum 2 times the maximum range water level ± 0.5cm. temperature : ± 0.5°C 0°C to 70°C 1cm/sec maxi. 3sec maxi. 6 mA

Removable connection cable Length of cable to be defined when ordering.

WATER LEVEL SENSORS PIEZORESISTIVE TRANSDUCER REF. C1. 12 GENERAL The water level is measured by a pressure transducer providing an electrical output proportional to the hydrostatic pressure of liquid related to the atmospheric pressure. The sensor is generally constituted of a silicon piezoresistive element. The sensor is connected to the data logger with a specific cable.

MEASUREMENT SPECIFICATIONS Transmission to the logger is of true binary type through a low speed (100 bits/sec) synchronous serial transmission allowing « long distance » communications CONDITIONS OF USE The sensor has to be strongly fixed at the bottom or at a defined level in the river bed, linked to the data logger through the connecting cable. This one should be protected in its submerged part as well as in its aerial part against damages. Normally with this type of device the distance between the sensor and the logger can be more than 1 km. TECHNICAL SPECIFICATIONS Range of measurement : Temporary over pressure : Accuracy : Working temperature : Tracking speed : Acquisition time : Supply consumption :

0 to 10 m. minimum 2 times the maximum range water level ± 0.5cm. 0°C to 70°C 1cm/sec maxi. 3sec maxi. 6 mA

Removable connection cable Length of cable to be defined when ordering.

METEOROLOGICAL SENSORS TIPPING BUCKET RAINGAUGE REF. C1. 31 GENERAL The principle of this type of recording gauge is very simple. A light metal container id divided into two compartments and is balanced in unstable equilibrium about a horizontal axis. The rain is led from a conventional collecting funnel into the uppermost compartment. As for the raingauge, the size of the opening of the collector is not really important, but a standard area of about 400cm² should probably found convenient. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger. The data logger has to be connected simultaneously to a pressure sensor for water levels and to a tipping bucket rainfall gauge fitted with a switch. MEASUREMENT SPECIFICATIONS After a predetermined amount of rain has fallen, the bucket became unstable in its present position and tips over to its other position of rest. The compartments of the container are so shaped that the water can now flow out of the lower one and leave it empty. Meanwhile, the rain falls into the newly positioned upper compartment. The movement of the bucket, as it tips over, is used to operate a relay contact and produce a record that consists of discontinuous steps. The distance between each step represents the time taken for a pre6specified amount of rain to fall. For many hydrological purposes, in particular for heavy rainfall areas and flood warning systems, 0.5 to 1.0 millimetre buckets are satisfactory. CONDITIONS OF USE All gauges in any area or country should have comparable exposures, and the same siting criteria should be applied to all. The gauge should be exposed with its orifice being horizontal over ground level. The height of the gauge orifice above the ground should be as low as possible because the wind velocity increases with height, but it should be high enough to prevent splash from the ground. A standard height of one metre is recommended. When adequate conditions from the wind is not possible, individual objects should not be closer to the gauge than a distance equal to four times their height. TECHNICAL SPECIFICATIONS Collector area : Accuracy : Output type :

200 cm² to 1000 cm² about 3% 1 mercury dry switch

Tipping bucket gauge according to the collector area (0.5 mm for a 400 cm² collector area)

METEOROLOGICAL SENSORS AIR TEMPERATURE REF. C1. 51 GENERAL The air temperature sensor is generally mounted on a support at 2m above the ground level, sheltered in a mini-shield. A specific software should be provided for data processing, allowing calculation of daily results as : minimum, maximum and average values with the instant of the extremes. The spent time records have to be adjustable : six minutes, thirty minutes, one hour, four hours, six hours, daily, etc.

TECHNICAL SPECIFICATIONS Sensor element : Accuracy :

Platinium 100 ohms to 0°C. 0.1°C.

Mini-shield to be ordered

METEOROLOGICAL SENSORS RELATIVE HUMIDITY REF. C1. 52 GENERAL The air temperature sensor is generally mounted on a support at 2m above the ground level, sheltered in a mini-shield. A specific software should be provided for data processing, allowing calculation of daily results as : minimum, maximum and average values with the instant of the extremes. The spent time records have to be adjustable : 6 minutes, thirty minutes, one hour, four hours, six hours, daily, etc.

TECHNICAL SPECIFICATIONS Sensor element : Range : Correction : Accuracy :

generally variable capacitor 0 to 100% temperature and Hysteresis effects. 1 to 2%

Mini-shield to be ordered OBSERVATIONS : The air temperature and relative humidity sensors could be sheltered in a single minishield.

METEOROLOGICAL SENSORS ANEMOMETER REF. C1. 53 GENERAL The three cups anemometer has been designed to provide an integrated wind speed system. The rotor of the three cup transmitter turns at a speed proportional to wind speed : a 1m.s-1 wind causes the rotor to turn at 1 revolution/sec. An inductive proximity sensor or an opto-electronic detector outputs a pulsed signal which is proportional to wind speed. A specific software should be provided for data processing, allowing calculation the results during the chosen period of time and the maximum speed. The spent time records have to be adjustable : 6 minutes, thirty minutes, one hour, four hours, six hours, daily, etc. GENERAL TECHNICAL SPECIFICATIONS Range : Accuracy : Threshold : Power supply :

0.3 to 50 or 60 m.s-1 0.5 m.s-1 0.2 m.s-1 12 Vdc

METEOROLOGICAL SENSORS VANE REF. C1. 54 GENERAL The vane is designed to measure the wind direction with a continuous rotation potentiometric transmitter. A specific software should be provided for data processing, allowing calculation the results during the chosen period of time The spent time records have to be adjustable : 6 minutes, thirty minutes, one hour, four hours, six hours, daily, etc.

TECHNICAL SPECIFICATIONS Scale : Accuracy : Threshold : Power supply :

O to 360°c ± 5° ± 0.5°C 12 V dc.

METEOROLOGICAL SENSORS PYRANOMETER REF. C1. 55 GENERAL The incident total solar short wave radiation should be measured with a pyranometer, and the output should be recorded continuously. Principle : Most modern types of pyranometers are based on multi-junction thermopiles and are covered by single or double glass domes which allow only radiation in the 0.3-3 µm to reach the sensitive pyranometer surface.

GENERAL TECHNICAL SPECIFICATIONS Transducer : nickel chrome constantan thermopiles Spectral sensitivity : 0.3 to 3 microns Response time : 4 sec. Range : generally 0.3 to 50 or 60 m.s-1 Accuracy : 0.5 m.s-1 Power supply : 12V dc Consumption : 5 mA max.

METEOROLOGICAL SENSORS HELIOGRAPH REF. C1. 56 GENERAL The heliograph is conceived for an automatic measurement of sunshine duration. Principle : The end of an optical fiber resolves around the sun axis. The openning angle is limited by an optical diaphragm. At the other end, a photocell detector receives the light pulses when the fiber window meets the sun. The photocell signal is compared to a threshold.

GENERAL TECHNICAL SPECIFICATIONS Transducer : Spectral response : Threshold : Power supply : Consumption : Stability :

photocell 0.3 to 12 microns about 120 W/m² 6 to 12 Vdc 2 to 6 mA° 0.4% year

WATER QUALITY SENSORS REF. C1. 57 GENERAL Most of the water quality probes are multi-parameter probes, and are able to measure simultaneously 4 to 8 (sometimes more) parameters. They should be designed in such a way that they can be connected to a data logger (DCP) or to a computer via a RS 232 port. They should be able to be used in different field conditions as : surface water (river), ground water, waste water,.... The usual measured parameters are : For a 4 parameters multi-probe :dissolved oxygen, temperature, pH, Conductivity. For a 8 parameters multi-probe : dissolved oxygen, temperature, pH, specific conductance, redox, depth, salinity, turbidity. GENERAL TECHNICAL SPECIFICATIONS Output : Power supply : Operating depth :

RS 232 and/or amphenol connection to DCP 12V 0 to ( to be define )

PARAMETER

RANGE

ACCURACY

RESOLUTION

Temperature

-5°C to +50°C

± 0.15°C

0.01°C

Specific Conductance

0 - 100 mS/cm

± 1%range

4 digits

pH

0 - 14 units

± 0.2 unit

0.01 unit

Dissolved Oxygen (mg.l-1)

0 - 20 mg.l-1

± 0.2 mg.l-1

0.01 mg.l-1

Dissolved Oxygen (% sat.)

0 - 200%

± 2.5%

0.1%

Redox

-999 - 999mv

± 20 mv

1 mv

Depth

0 to ------

1%

0.1%

Salinity

0 - 70 PPT

± 0.2 PPT

0.1 PPT

Turbidity

0 - 1000 NTU

± 5% range

4 digits

DATA TRANSMISSION REF. C1. 58 GENERAL Different data transmission systems are today available : Radio ; telephone (land lines and cellular phones) ; satellites (geostationary satellites : METEOSAT, GOES and orbiting satellites : ARGOS). The choice of a given telemetering system depends on several criteria as : - Necessity of data transmission in real time or near real time - Day to day network monitoring for water resources - Monitoring of a flood warning network - Local infrastructures for radio and phone networks - Local laws on transmission licences authorization - Implementation and running costs - Maintenance facilities Whatever the chosen telemeterering system is, the equipment have to be in accordance with the local standards for radio and telephone, and with the international standards for the satellite systems. The data loggers and DCPs should be equipped with a GPS receiver, a phone MODEM or Goes radio transmitter and its antenna. We present hereafter some advantages and disadvantages of the main different systems TELEMETERING SYSTEMS RADIO telemetering system (VHF / UHF) Advantages : - low implementation cost if a network is already available - low running cost Disadvantages : - High cost for a new network implementation - Short distance between the stations and the radio relays (50 km maxi.) - Licence authorization - Usefull for a local network (catchment ) PHONE telemetering system (land lines or cellular) Advantages - Low implementation and running costs - Full duplex (station/office and reverse) - Programmable thresholds for warning system Disadvantages - Storms sensibility (risks of failure) - Geographical catering of the network not always sufficient in uninhabited areas SATELLITES (ARGOS - GOES) Advantages - Reliability and robustness of the system - Near real time data acquisition (for ARGOS) real time data acquisition (for GOES) - Implementation cost not too expensive - Data acquisition via a Direct Earth Receiving Station or via Internet Disadvantages - Running cost

DISCHARGE MEASUREMENT CURRENT METERS (HORIZONTAL AXIS) PYGMY TYPE REF. D1. 10 GENERAL The « Pygmy type » current meter is designed for discharge measurement in rivers, small channels, conduits, etc. with low water levels (few centimetres depth) and no too high velocities. The Pygmy current meter is generally used with a rod for discharge measurement by wadding. According to the mean flow velocity a set of propellers of various hydraulic pitch has to be proposed. The light weight of the propellers (generally aluminium made) allows a low start speed, and the propeller diameter (from 3 to 5 cm) measurements in low depth water (about 4cm). The Pygmy current meter has to be used with a counter set for counting the propeller revolutions, according to the flow velocities. MEASUREMENT SPECIFICATIONS Depending on the pitch of the propellers used, different velocity ranges may be obtained. For the determination of flow velocity a calibration of the Pygmy current meter with the relating propeller is necessary in order to determine the water velocity « v » according to the general equation : v=a.n+b a = hydraulic pitch of the propeller (m) determined by test runs n = number of propeller revolution per second b = meter constant (m/sec) determined by test runs. As main of the propellers have a component effect in the velocity measurement, the limited angular angle for which the propeller measures the true velocity has to be specified. where :

CONDITIONS OF USE The Pygmy current meter is generally mounted on a thin rod for measurements in low depth water. It can be interesting to used also this type of current meter in higher water depth (about 1 metre) or for measurements from a bridge, in case of very low velocities. In these situations the current meter has to be mounted on a stronger rod in using an additional device to adapt it to the new condition. TECHNICAL SPECIFICATIONS The Pygmy current meter should be delivered with the surrounding devices : PROPELLERS : (delivered with the rating tables) Diameter Pitch v min 30 to 50 mm 0.05 to 0.50 m. 0.025 to 0.05 m/s.

v. max 1.0 to 4.0 m/s

Component effect 10° to 30 °

ROD : diameter from 10 to 20 mm, length 1 to 3 metres, relocating device for bigger rod ; COUNTER SET ; CONNECTING CABLE. INSTRUMENT CASE

DISCHARGE MEASUREMENT CURRENT METERS (HORIZONTAL AXIS) STANDARD TYPE REF. D1 .20 GENERAL The « standard » current meter is designed for discharge measurement in rivers, channels, conduits, etc. on different fixing devices for use on rod or with a sounding weight. According to the mean flow velocity a set of propellers of various hydraulic pitch has to be proposed. The propeller size varies generally from 80 to 125 mm and the pitch from 0.125 to 1.0 meter. The standard current meter has to be used with a counter set for counting the propeller revolutions, according to the flow velocities. MEASUREMENT SPECIFICATIONS Depending on the pitch of the propellers used, different velocity ranges may be obtained. For the determination of flow velocity a calibration of the standard current meter with the relating propeller is necessary in order to determine the water velocity « v » according to the general equation : v=a.n+b a = hydraulic pitch of the propeller (m) determined by test runs n = number of propeller revolution per second b = meter constant (m/sec) determined by test runs. As main of the propellers have a component effect in the velocity measurement, the limited angular angle for which the propeller measures the true velocity has to be specified. where :

CONDITIONS OF USE The standard current meter can be used with a rod (generally 20 mm diameter), using sometimes a relocating device for an easy use in rivers, or with sounding weights from a bridge or a boat or a cable-way equipment. In these last situations some additional devices have to be ordered TECHNICAL SPECIFICATIONS The standard current meter should be delivered with the surrounding devices : PROPELLERS : (delivered with the rating tables) Diameter Pitch v min 80 to 125 mm 0.25 to 1.0 m. 0.025 to 0.05 m/s. Propeller are made of brass or plastic or aluminium.

v. max 2.5 to 10.0 m/s

ROD : diameter about 20 mm, length from 1 to 4 metres, relocating device; COUNTER SET ; CONNECTING CABLE. INSTRUMENT CASE

Component effect 5° to 45°

DISCHARGE MEASUREMENT CURRENT METERS (VERTICAL AXIS) PYGMY TYPE REF. D1. 30 GENERAL The « Pygmy type » current meter is designed for discharge measurement in rivers, small channels, conduits, etc. with low water levels (few centimetres depth) and no too high velocities. The Pygmy current meter is generally used with a rod for discharge measurement by wadding. The light weight of the bucket wheel (generally aluminium made) allows a low start speed, and the propeller diameter (from 3 to 5 cm) measurements in low depth water (about 4cm). The Pygmy current meter has to be used with a counter set for counting the propeller revolutions, according to the flow velocities. MEASUREMENT SPECIFICATIONS Depending on the pitch of the propellers used, different velocity ranges may be obtained. For the determination of flow velocity a calibration of the Pygmy current meter is necessary in order to determine the water velocity « v » according to the general equation : where :

v=a.n+b a = hydraulic pitch of the propeller (m) determined by test runs n = number of revolution per second b = meter constant (m/sec) determined by test runs.

CONDITIONS OF USE The Pygmy current meter is generally mounted on a thin rod for measurements in low depth water. It can be interesting to used also this type of current meter in higher water depth (about 1 metre) or for measurements from a bridge, in case of very low velocities. In these situations the current meter has to be mounted on a stronger rod in using an additional device to adapt it to the new condition. TECHNICAL SPECIFICATIONS The Pygmy current meter should be delivered with the surrounding devices : Cup or bucket wheel with six cups comprising the rotor or Vane with two S-shaped vanes comprising the rotor ROD : diameter from 10 to 20 mm, length 1 to 3 metres, relocating device for bigger rod ; COUNTER SET ; CONNECTING CABLE. INSTRUMENT CASE

DISCHARGE MEASUREMENT CURRENT METERS (VERTICAL AXIS) STANDARD TYPE REF. D1 .40 GENERAL The « standard » current meter is designed for discharge measurement in rivers, channels, conduits, etc. on different fixing devices for use on rod or with a sounding weight. According to the mean flow velocity a set of propellers of various hydraulic pitch has to be proposed. The propeller size varies generally from 80 to 125 mm and the pitch from 0.125 to 1.0 meter. The standard current meter has to be used with a counter set for counting the propeller revolutions, according to the flow velocities. MEASUREMENT SPECIFICATIONS Depending on the pitch of the propellers used, different velocity ranges may be obtained. For the determination of flow velocity a calibration of the standard current meter is necessary in order to determine the water velocity. CONDITIONS OF USE The standard current meter can be used with a rod (generally 20 mm diameter), using sometimes a relocating device for an easy use in rivers, or with sounding weights from a bridge or a boat or a cable-way equipment. In these last situations some additional devices have to be ordered TECHNICAL SPECIFICATIONS The standard current meter should be delivered with the surrounding devices : Cup or bucket wheel with six cups comprising the rotor or Vane with two S-shaped vanes comprising the rotor ROD : diameter about 20 mm, length from 1 to 4 metres, COUNTER SET ; CONNECTING CABLE. INSTRUMENT CASE

DISCHARGE MEASUREMENT CURRENT METERS ELECTROMAGNETIC TYPE REF. D1. 50 GENERAL This current meter is designed for discharge measurement in shallow water, minimum velocities. As there is not moving piece e.g. a propeller, this device is very accurate in hard measurement conditions as plant-loaded water, polluted water etc.

MEASUREMENT SPECIFICATIONS The magnetic induction principle according to Faraday offers the possibility to measure lowest velocities without any mechanically moved parts : if an electro-conductive medium moves in a magnetic field, then a voltage is induced in this conductor : U=B.L.V U : measuring voltage ; B : magnetic field ; L : length of the conductor ; V : velocity Thus the output voltage is linearly proportional to the velocity of the electric conductor. Depending on the principle, the measurement in each case should only covers the axial component of the flow velocity, that means by this a 100% component effect is get. CONDITIONS OF USE The electro-magnetic current meter can be used with a rod (generally 20 mm diameter), using sometimes a relocating device for an easy use in rivers. TECHNICAL SPECIFICATIONS Operating temperature : - 5°C to 70°C Material of probe : generally impact-proof epoxyresin Material of electrodes : generally Titanium Minimum conductivity of the measuring medium : 5 µS Specific power supply and display device has to be ordered with the apparatus CONNECTING CABLE. INSTRUMENT CASE

DISCHARGE MEASUREMENT ULTRASONIC MEASURING STATION REF. D2 .10 GENERAL This equipment carried out the discharge calculation relating to the water level and the mean flow velocity at time of measurement determined by an ultrasonic method.

MEASUREMENT SPECIFICATIONS Two or four transducers are installed on the river banks (half on each bank), and the device measured the return time of the ultrasonic waves between the transducers from one bank to the other. The mean flow velocity is calculated from the time difference between the go and back way. CONDITIONS OF USE This equipment should be used in rivers up to 400 meters wide. Some civil works are generally needed for the transducer installation . TECHNICAL SPECIFICATIONS Range :

water level Width Flow velocity

Resolution Accuracy :

1 to 10m 1 to 400m 0 to 10 m/s 0.01 m/s

water level Flow velocity

Temperature : Power supply : battery and solar panel

± 1cm ± 1% -5°C to 60°C

DISCHARGE MEASUREMENT ACOUSTIC DOPPLER CURRENT PROFILER REF. D2. 20 GENERAL This device carried out discharge measurements in measuring vertical velocity profiles in using the acoustic energy. It measures also both its own speed and direction relating to the river bottom in using the same technique as for the flow velocity measurement. MEASUREMENT SPECIFICATIONS Relating to the river depth, the profiler divides the vertical profiles in a number of elementary cells, and measures the mean velocity and direction of each cell. From these data it calculates the total discharge. As it is fitted with an internal compass, it calculates also its direction to the north. So it is not necessary for the boat to follow a straight cross section for carrying discharge measurements. CONDITIONS OF USE The profiler should offers both installation possibilities on a boat or as a sentinel fixed at the bottom of the river for continuous discharge measurement. As the profiler should be equipped with a pitch and roll compensation system, the boat movements (in case of flood with turbulent flow) are not an inconvenient for carrying the measures. This equipment should be used in rivers up to 400 meters wide. Some civil works are generally needed for the transducer installation . TECHNICAL SPECIFICATIONS Frequency range : from 300kHz to 1200 kHz. e.g. 600 kHz for shallow waters (less than 20m). Temperature and salinity compensation Pitch and roll compensation Power supply : external battery 12 to 24V Waterproof battery pack for sentinel using

DISCHARGE MEASUREMENT ADDITIONAL DEVICES RODS REF. D3. 10 GENERAL Rods are used to operate the current meter for discharge measurements by wadding.

MEASUREMENT SPECIFICATIONS This equipment is a part of the light equipment needed for discharge measurements in rivers not too deep (less than one meter) and with flow velocity less than one meter per second. CONDITIONS OF USE Rods are used sometimes from a foot-bridge with a specific trolley. TECHNICAL SPECIFICATIONS Length : 4 metres Diameter : generally 20mm Order a specific device for relocating the current meter along the vertical measurement For deeper rivers with velocity more than 1 meter/sec : ovoid shape rod Instrument case

DISCHARGE MEASUREMENT ADDITIONAL DEVICES WINCHES REF. D3. 20 GENERAL Winches are used to operate the current meter mounted with a sounding weight for measurements in deep waters and at high flowing velocities. The measurements in theses situation should be carried out from a bridge, in using a boat or a cable-way. According to the sounding weight (and so to the water depth and the flow velocity) different sizes of winches are available.

MEASUREMENT SPECIFICATIONS This equipment is a part of the heavy equipment needed for discharge measurements in rivers deeper than one meter and with flow velocity higher than one meter per second. CONDITIONS OF USE The single drum winch is normally mounted on a jib for discharge measurements from a bridge or from a boat. TECHNICAL SPECIFICATIONS The power of the winch is chosen relating to the sounding weight (from 5 to 25 kg ; 50 kg ; 100 kg). The winch should be fitted with an electrical-carrying cable connecting the sounding weight to the winch. The length of the cable is ordered in respect with the maximum depth of the rivers. A cable is needed to connect the winch to the counter. Some winches can be equipped with an additional device for integration measurement of the velocity in a vertical section. Instrument case

DISCHARGE MEASUREMENT ADDITIONAL DEVICES SOUNDING WEIGHTS REF. D3. 30 GENERAL Sounding weights are used to operate the current meter for measurements in deep waters and at high flowing velocities. The measurements in theses situation should be carried out from a bridge, in using a boat or a cable-way. According to the water depth and the flow velocity, different sizes of sounding weights are available.

MEASUREMENT SPECIFICATIONS This equipment is a part of the heavy equipment needed for discharge measurements in rivers deeper than one meter and with flow velocity higher than one meter per second. CONDITIONS OF USE The sounding weight is suspended to an electrical carrying cable operate from a winch normally mounted on a jib for discharge measurements from a bridge or from a boat. TECHNICAL SPECIFICATIONS Relating to the water depths and flow velocities different sounding weight are available from 5 to 100 kg. The sounding weight should be fitted with an electrical contact for the bottom signal. A stabilizer tail should be connected to the sounding weight. Instrument case.

DISCHARGE MEASUREMENT ADDITIONAL DEVICES CABLE-WAYS REF. D3. 40 GENERAL Cable-ways are designed for flow discharge measurement with cablesuspended current meters where no bridges or measuring boats are available. The horizontal and vertical displacements of the suspended current meter is effected with the aid of two single drum winches or with the aid of a double-drum winch. The measurements in this situation should be carried out from the river bank where the double-drum winch is installed or, if the cable-way is fitted with a basket for the measuring team, from this position. According to the river width, the depth and the flow velocity, different sizes of cable-way stations are available. MEASUREMENT SPECIFICATIONS This equipment is a part of the heavy equipment needed for discharge measurements in rivers deeper than one meter and with flow velocity higher than one meter per second. Some cable-way stations are available for river width up to 400 meters. CONDITIONS OF USE The cable-way station includes the winches, mounted on a support stand, sheltered in a small house, and on the opposite bank one another stand. A main cable is tight between the two banks, supporting the mobile trolley of the sounding weight or the basket for the workers. A second cable (electrical-carrying cable) support the sounding weight and transmit the current meter pulses. The installation has to be made in a very safe way, to prevent any accident or damage for the operators and the equipment. TECHNICAL SPECIFICATIONS According to the type of sounding weight (25, 50, 100kg) to the width and the depth of the river as well as the maximum flow velocity, the type of winches, the length and the diameter of the main carrier cable have to be defined carefully. If power supply is available at site, electrical winches could be used. For small rivers (width less than about 60 meters) some transportable cable-ways are available. The support stands have to be fixed permanently on both banks. The winches mounted on a frame (lighter than the previous ones) are installed just before starting the measurements. In such a way, a single device could be moved and used to several hydrometric stations. Centimetric counters have to be available for depth and distance measurements.

DISCHARGE MEASUREMENT ADDITIONAL DEVICES COUNTERS REF. D3. 50 GENERAL All current meter needs a counter set for the record of propeller revolutions and the calculation of flow point instantaneous velocity . Most of them have an internal clock and can allowed preset time or number of pulses. MEASUREMENT SPECIFICATIONS Electronic counters must allow integration measurements with remaining term measurement.

CONDITIONS OF USE The counters have to be run under hard conditions e.g. under rainfall. For the basic models a separate top watch has to be used. TECHNICAL SPECIFICATIONS Preset time :25, 30, 50 seconds Choice between preset time or number of pulses Zero-setting by press button or synchronous with a restart measurement Counting frequency : up to 20 pulses per second Temperature range : -20°C to + 60°C Power supply : dry cells

GROUND WATER GAUGE REF. E1. 10 GENERAL This dip meter is designed for an easy water level measurements in wells, observation pipes, bore-holes, as well as for the control of pumping tests.

MEASUREMENT SPECIFICATIONS As soon as the electrode of the measuring probe touches the water surface, a signal lamp on the instrument lights up or a beep rings, and the water level can be read from the measuring tape in metres and centrimetres.

TECHNICAL SPECIFICATIONS Measuring range (to be precise when ordering) : 20, 50, 100, 200, 500 metres Accuracy : 1 cm for a measuring range of 100 m. Tape material : polyamid-coated steel tape, graduations in centimetres Cable drum : hard rubber Some gauges can be fitted both with a temperature probe Measuring range : -5°C to + 45°C Resolution : 0,1°C Accuracy : ± O,2°C

GROUND WATER DATA LOGGER REF. E1. 20 GENERAL These data loggers are designed for the acquisition and recording of water levels measured by a sensor into a well. The water temperature is generally displayed on the terminal. The data storage is carried out on static and non volatile memories (mainly EEPROM technology) inside the logger.

CONDITIONS OF USE Some data loggers are specifically designed for ground water monitoring, but some surface water data loggers are suitable for ground water measurements. MEASUREMENT SPECIFICATIONS Adjustable spent time and minimum change in range should be available (example from 01 to 99 mn and from 01 to 99 cm) for data storage and optimisation of memory capacity. The memory capacity must allow an autonomy of few months, according with the variations in water levels. TECHNICAL SPECIFICATIONS Measuring range (to be precise when ordering) : 20, 50, 100, 200, 500 metres Accuracy : 1 cm for a measuring range of 100 m. Input : limnimetric sensor Output : RS 232C for connection of a specific device as initialization terminal, or laptop computer, or satellite transmitter, MODEM..... Climatic conditions : from -20° to + 70°C ; humidity : 100% Calendar time base : by initializable real time clock, drift less than one minute a month. Power supply by internal battery or external battery and solar panel. Waterproof connections