PROCESS AND APPARATUS FOR AIRBORNE SURVEYS OF CATHODIC PROTECTION OF UNDERGROUND PIPELINES

摘要

: A process and apparatus using airborne equipment for monitoring the current level in a pipeline includes flying an aircraft bearing at least one AC magnetometer above an underground pipeline. The magnetic field created by a DC current impressed on the pipeline is detected and extraneous signals other than those created by the magnetic field of the pipeline are filter out. The linear position of the magnetometer with respect to the pipeline is detected as the aircraft is flown and a discernible record of the magnitude of the magnetic field in relation to the linear position of the magnetometer with respect to the pipline is produced. The technique is cheaper and more reliable than those previously proposed for the purpose.