Pipe Current Mapping (PCM)
This technique is used to detect the Cathodic Protection current flow. The PCM system consists of a portable transmitter and a hand held receiver. The transmitter is connected to the CP station to apply a special near DC signal to the pipeline. The receiver later might identify the position and depth of the pipe by collecting the signal transmits by the transmitter up to 30 km (19 miles) from the transmitter.