WATER LEVEL METER

If you are familiar with these instruments you know how expensive they are. Southern DataStream wanted to build a non-expensive water level meter, reliable enough to be used in the field. After some research in the Internet, the circuit attached in the file below was found and implemented. You might find interesting and useful to visit the website publishing this one and many other electronic circuits for varied applications http://www.imagineeringezine.com/. I found it is very important to use exactly the same components, the same beeper which has very small power consumption. When I tried to buy the beeper, I found they would only sell me 100 or more!! So the sales rep from Star Micronics America, Christine Stima (ph= (732) 623-5500 ext. 549) in NJ, sent me three of these little beepers as samples. The other important consideration is to use probes with enough area to be able to overcome the water resistance. Specially knowing that some of the ground water has small conductivity. The water level meters are being used very successfully in the field now.

Circuit design (PDF file)

Here is how the probes and enclosure look in our water level meter:

We are using two solid aluminum rings as probes. The plastic pipe between the rings is filled with silicone for isolation. Two wires are run through the PVC up to circuit enclosure.

The enclosure is a rubber 2 inches pipe with a sliding PVC terminator as lid.

The circuit board is really small and is set at the bottom of the enclosure, A 1.5V battery powers the circuit. The beeper is glued to the sliding top where we opened a little hole to give a path out for the beep sound.