Method for measuring resistance of metal ground structure or ground resistivity, involves opening connection between pipeline and electric earth electrode for measuring potential difference between pipeline and earth electrode

摘要

The method involves using a commutable electric connection to electrically and temporarily connect a pipeline under cathodic protection to an electric earth electrode, where the connection includes a resistance of non-zero value in a closed position. The connection is closed for measuring a current passing through the pipeline towards the earth electrode. The connection is open for measuring a potential difference between the pipeline and the earth electrode. A resistance of the earth electrode compared to a remote ground is measured from a specific formula.