purchase of electronic self-recording tidal staff gauge, including detailed demonstration of the equipment to the officers concerned, one each for all three sections under coastal engineering sub division ernakulam , supply of automatic staff gauge recorder, to record the water level variations of a place using capacitive rod principle with the following specifications data to be recorded: water level variations at accuracy of 4mm. digital separation of fluctuating water level: provision to digitally separate the sudden fluctuations in water level and record the average water level fluctuations in rivers, lakes or other water bodies. local data storage: sd card with facility to down load the data to computer or smart phone. specification of the type of sensor used: capacitance rod type water level recorder for small water columns up to 2 meters. sensor measures the water level fluctuations in small creeks, streams, or other water body with high accuracy. range: 0 to 200 cm. accuracy: +/- 4mm. free from: atmospheric pressure compensation and temperature effect. material: stainless steel and plastic. output: 0 to 5 volt atmospheric pressure and temperature compensation: inbuilt facility.