The present invention relates to the measurement method to be installed is connected to the potential terminal connected to the gas pipe and the wire to measure the electric potential in the manner of a steel gas pipe buried in the ground.
In particular, urban areas other than roads, mountains, land or rail are installing a measured approach potential installed Competition (pole type) on the ground if the site, forming a terminal fixing plate made of the inside of the measured conductor and dysfunction conductor electronics donor (D1, D2) for measuring the potential first and second wires (L1, L2) with the pipe (P) measures the electric potential for the electric wire 3 and 4 (L3, L4) for individually measuring the terminal is fixed by an additional release work can not be shortened way potential measuring time and the measuring compartment body to the lower forming wire (L1, L2, L3, L4) drawn out groove in box bottom and the measurement of the body when laying on the lower part of the body in the ground inside wherein the wire to be drawn out to one another abuts is damaged body protective coating provided on the outer periphery of the electric wire due to the increase of an electric current to maintain a fair manner the potential due to the leakage of an electric current from the coating damaged portion of the wire anodes, that is and to reduce the maintenance costs of the system by preventing potential equipment replacement cycle speed of the electron donor (D1, D2, donor).