Abstract: A method and apparatus for making relatively closely spaced pipe-to-soil potential difference measurements, the method and apparatus being characterized by a dual function economically disposable, relatively lightweight, flexible electrical wire that provides for the necessary electrical connection to a pipeline and also for accurate distance measurement at the test end of the wire along the pipeline. The wire is electrically connected at a test station or lead to the pipeline and is played out from a supply thereof carried by the surveyor along the length of the pipeline through distance measuring means. At each selected test location, the potential between the wire connected to the pipe and a reference electrode contacting the soil proximate the pipe are measured by a high resistance input meter. The wire is economically disposable and may be discarded when no longer used eliminating the need to rewind the wire.