Lost Valve-Manhole Detection (Buried Metals)

It is used to locate buried valves, manholes, and metal objects.

Metal detectors operate based on the principle of sending and receiving electromagnetic waves. The transmitted electromagnetic wave induces an Eddy or a Faraday current when it encounters a metal object. This induced current affects the coil in the detector, causing small variations in the signal. These minor signals are amplified within electronic circuits and then sent to a speaker to produce an audible sound. Some detectors also feature needle-based or digital signal measurement circuits.