Cable light solder
The cable light solder , also known as light solder , is used to manually measure the depth of the water level in wells , observation wells and narrow bores . There is an electrode on a tape measure in which two current-carrying wires are incorporated. This electrode, hanging on the tape measure, is slowly lowered from the cable reel into the well or shaft. As soon as the electrode (zero point) of the solder touches the water level, a current flows from the electrode to the probe body (counter electrode), the circuit is closed and the signal lamp on the cable drum lights up. By slightly lifting the device, the lamp goes out immediately, so the surface of the water can be felt. The depth of the water level (thus the vertical distance from the measuring point downwards) can now be read from the reference mark (e.g. upper edge of the observation well) on the scale of the measuring tape. The measuring principle is based on the electrical conductivity of water.