1. Accurate monitoring of cathodic protection status. Sacrificial anode protection for potential measurement. 2. In impressed current cathodic protection system for automatic control of the stability of the signal source, buried underground metal structures for the cathodic protection works. 3. Can be buried in the need to monitor the position and who can not enter. Such as: The end of the center of a large container. Underground fuel tanks and chemical storage tanks can not be close to the location between the city's pipe network under the road, can advance in engineering first laid during the construction period, long-term use. 4. Pipeline cathodic protection of the telemetry signal.