Need to measure the depth to water in a monitoring well or borehole but don't have several hundred dollars to buy a fancy dip meter? Never fear! Necessity is the mother of invention, and I've put together one from parts totaling about $13. This device is so easy to make even an ecologist can build one. (I can say that because I'm an ecologist!) The PDF link below gives instructions on how to build a simple dip meter using a 9V battery and a smoke alarm buzzer. The diagrams are well illustrated, too, if I do say so myself. ;)
The who, what, when, where and why of agricultural water issues.