subject: How Does a Metal Detector Work? [print this page] A different, newer type of metal detector uses a technology called pulse induction. This metal detector blasts the ground with a large electromagnetic pulse, and observes the length of time it takes for the voltage to decrease to ambient levels. If there is a conductive object under the ground, it will take a longer amount of time for the voltage to decrease. It is a small effect, but modern sensors can pick it up well. This technique has certain advantages over conventional metal detectors, such as the ability to detect objects under highly mineralised "black sand."
