Cable locators, radio locators or electromagnetic locators allow the location of metal cables and pipes in a non-destructive way and in almost any type of subsurface material.
Electromagnetic locators, hereinafter locator, are based, as the name suggests, on electromagnetism.
Actually, a locator does not detect cables or pipes, but detects the magnetic fields that are generated around a cable or pipe. Said magnetic field is generated by the current that flows through the cable. This field is not affected by the insulation of the cables or by the conditions of the subsoil materials.
The current that generates the magnetic field to be detected can be the cable’s own circulating current, or it can be induced by an external generator. Depending on whether a detection is made from listening to the service’s own magnetic field, or if we apply a current through the generator to generate a certain magnetic field, we will have the two possible detection means, passive mode and active mode.