STUDY ON WATER LEVEL SENSORS
Dr. N. SAI BASKAR REDDY,
Co- Ordinator, ClimaAdapt Project,
Miss. Hafisa Hameed
Miss. Jomol T Joseph
UNDER THE GUIDENCE OF :
• Receives energy from one system and transmit it to another
• i.e. physical variable into signal variable
• Energy transmitted may be electrical, mechanical or acoustical
TYPES OF SENSORS
> contact type
• submerged at a fixed level under the water surface.
• measures the equivalent hydrostatic pressure of the water above the
• It is like weighing the water.
> contact type
• The Staff Gage provides a quick and easy visual indicator of water
• Made with a durable baked-on porcelain enamel finish on a metal
• are hydrostatic pressure sensors
• are used to measure water level by detecting the pressure
required to force air through a submerged tube.
• the tube is mounted with the end of the tube below the water
surface being measured, and the air emerges from the bottom
of the tube as a stream of bubbles
Digital Pulsed Doppler
• Pulsed wave (PW) Doppler systems use a transducer that
alternates transmission and reception of ultrasound.
• One main advantage of pulsed Doppler is its ability to provide
Doppler shift data selectively from a small segment along the
ultrasound beam, referred to as the “sample volume”.
• The location of the sample volume is operator controlled.
> Contact type
• The system is designed to measure both, the vector and the
magnitude (using twin velocity beams) of individual velocity cells
to account for velocity variations within the flow and obtain the
• A third vertical acoustic or hydrostatic sensor beam is used to
measure water level.
> Non contact
• operate by sending a sound wave generated from a piezoelectric
transducer to the surface of the process material being measured.
• transmitter measures the length of time it takes for the reflected sound
wave to return to the transducer.
• successful measurement depends on the wave, reflected from the process
material and moving in a straight line back to the transducer.
• factors such as dust, heavy vapours, tank obstructions, surface turbulence,
foam, and even surface angles can affect the returning signal when using
an ultrasonic level sensor.
> Non contact
• Working principle is similar to ultrasonic sensors.
• operation of all radar level detectors involves sending
microwave beams emitted by a sensor to the surface of liquid.
• electromagnetic waves after hitting the fluids surface returns
back to the sensor which is mounted at the top.
• The time taken by the signal to return back i.e. time of
flight (TOF) is then determined to measure the level of fluid.
• Selection of right sensor
1. measuring range
>based on max. and min. water level
2. measurement interference
>natural or man made
e.g.: presence of large rock in canal gives
>details of permanent structures should
be collected.eg: bridge ,ridges etc.
4. environmental and seasonal conditions
>wind , wave, salinity ,bank stability etc.
should be determined
• Data acquisition
>process of sampling signals such as voltage, current
> these signals are further processed
>includes reporting information
>necessary steps followed after data analysis
LOCATION : DC4 Mirialaguda circle
• Sensor locations are identified with respect to the permanent
structures in the canal network.
• Difficult to get continuous power supply for the power input. In
such cases we can go for solar panels.
• Farmers are unaware about the sensors.
• Canal lining and maintenance works are now going on the field.
• Major portion of the canal was unlined.
• Before installation of sensors canal maintenance should be
done to get accurate measurement.
LEVEL CONVERSION TO DISCHARGE
• Using manning's formula
v = 1/n R 2/3 S ½
Q = Av
BED WIDTH TOP WIDTH n SIDE SLOPE
REACH 1 6.28m 5m 0.02 1 ½: 1
REACH 2 4.54m 3m 0.03 1 ½ : 1
REACH 3 5.13m 3 m 0.02 1 ½ : 1
REACH 4 4.70 m 3m 0.02 1 ½ : 1
REACH 5 4.70 m 3m 0.02 1 ½ : 1
CHILLAPUR BRIDGE 0.910 km
DILVARPUR BRIDGE 4.68 km
DILWAPUR S.L BRIDGE 10.22 km
S.L BRIDGE 13.20km
S.L BRIDGE 14.80 km
DROP CUM S.L BRIDGE 11 16.977 km
DROP CUM S.L BRIDGE 14 18.41 km
S.L BRIDGE 19.84 km
ROCKS PLACED TO INCREASE WATER LEVEL DURING LOW FLOWS
Based on study
• Since radar is independent of external weather conditions such as
rain, solar radiation, wind or fog, we believe that radar
measurement is actually more suitable to the major canals for
more accurate measurements. Economic considerations prefer
ultrasonic sensors if environmental conditions allow.
• From the data collected among the suppliers, by the cost and error
analysis, recommended radar sensors are,
>Digital water level recorder (DWLR-R)
CANAL SENSOR TYPE LIMITATION MAINTA
MAJOR RADAR NON
COST LESS 9
MAJOR ULTRASONIC NON
CANAL SENSORS TYPE LIMITATION MARK
• Another consideration is that adjustment and operation of
radar and ultrasonic instruments are easy than contact type.
• In open channels, the flow measurement error of ultrasonic
sensors, due to temperature error, can amount to more than
20%. Temperature sensitivity is around ± 15 -20 0 C
• Previously, the price difference between radar and ultrasonic
instrumentation was very high; today, the price of radar is
comparable to that of ultrasonics. But while considering large
scale installation a large amount variation will be there.
Canals Sensors Type Description Average cost for
Major RADAR Non-contact Highly accurate but
30000- 60500 Stand alone poles or
Major ULTRASONIC Non-contact Accurate but depends on
15670- 35000 Stand alone poles or
Major Digital doppler Contact Measures velocity also 10000 – 30000 Mounted to canal
Minor Digital doppler Contact Measures velocity also 10000 – 30000 Mounted to canal
Minor Pressure sensor Contact Based on weight of water 5000-25000 Submerged in canals
Minor Staff guages Contact Human recording 1000 Mounted along canal
• Permanent structures like bridges and drops are found to be the
suitable place for sensor installation.
• Major field challenge include theft and unawareness about
• Operating Temperature Range: –40° to +80°C
• Storage Ranges
>Temperature: –40° to +80°C
>Relative Humidity: 20% to 80% RH
• Vibration Resistance: Mechanical vibrations with 4 g and 5
to 100 Hz
DROP NO: 1 0.914 Km
DROP NO: 3 8.045 Km
DROP NO: 5 11.529 Km
DROP CUM REGULATOR 8 15.690 Km
DROP NO: 12 17.160 Km
DROP NO: 16 20.589 Km
DROP CUM REGULATOR 23 22.433 Km
DROP NO: 25 23.622 Km
• We would like to express our heart felt thanks to Er. L. Narayana Reddy,
Director general,WALAMTARI, for giving us this wonderful opportunity.
• We thank Dr. N. Sai Bhasker Reddy for his support, valuable guidance,
profound suggestions, constant backing, prolific encouragement and advice
throughout this project work at WALAMTARI. With deep respect.
• We sincerely acknowledge, Dr. Yella Reddy, for providing the necessary
information and related data and for the timely help rendered by him.
• We express our heartfelt gratitude to Sravanthi, water manager,
WALAMTARI, Pranith, WALAMTARI for providing relevant data and
necessary help and support for field data collection.
• We offer our hearty thanks to Vanitha ,AE (Irrigation and CAD Dpt),
Ramesh, FTC for their sincere and timely help in getting the necessary
information for the study.
• We express our heartfelt thanks to Krishna Reddy and Kiran for their
help extended towards us in course of this work.
• Above all we bow our head before the God Almighty whose blessings
empowered us to complete this work successfully.