Pipe and cable locators are specialized devices created for the purpose of pinpointing and distinguishing public utility services that run below the ground. These gadgets are used to pinpoint needed utility networks, to locate malfunctioning cables or to scan the area prior to digging or building on top. These gadgets are designed not only to find utility grids underground, but also to tell them apart and be able to locate the desired cable among other cables and pipes that might cover it. Estimation of depth is also necessary. Cable and pipe locators are usually made up of two parts. The first is the transmitter. It emits a signal into the ground. It can adjust the electromagnetic field that it creates to have a specific frequency that will suit a certain type of conductor in the cable or metal type of the pipe. The second part is the receiver. It picks up the field created around the pipe or a cable and traces it along the way. There are three main methods used in locating utility networks. The first is called direct connection, and the name speaks for itself - the transmitter part is attached to the wire while the receiver tracks the underground part of it. If there is no way to attach to a cable, the second method is used, which is called inductive or general inductive. The transmitter is placed strictly above the cable. It has disadvantages, as there may be multiple cables interfering with the signal. The third method is called inductive coupling and required the cable to be grounded.