US 2003/0074162 A1 · Cathodic protection remote monitoring method and apparatus

Abstract

A method for determining the influence of one of a plurality of cathodic protection circuits along a pipeline includes switching one of a plurality of cathodic protection circuits off, while the remainder of the plurality of cathodic protection circuits are left on, with a portable pipe-to-soil potential measurement unit measuring the pipe-to-soil potential along the pipeline. From these measurements, a calibration curve is generated and an apparatus for monitoring the cathodic protection circuits is strategically positioned on the pipeline. The apparatus includes a remote monitoring unit having a pipe-to-soil potential measurement unit for measuring the potential between the ground bed and pipeline. The remote monitoring unit is off except while making measurements. The remote monitoring unit may optionally include a pipeline current measurement unit connected at a second connection point on the pipeline for measuring the current passing through the pipeline between the first and second connection points.

Claims47

Dependent claims

A method for monitoring the cathodic protection status of a rectifier on a conductive structure comprising:

a) placing the rectifier having a first predetermined output at a first location on the structure;
b) changing the output of the rectifier to a second predetermined output;
c) measuring the difference between the first and second outputs of the rectifier at a plurality of locations on the structure, wherein the locations are remote from the rectifier at the first location;
d) recording the influence that the difference of the outputs has on the structure-to-soil potential at each location;
e) selecting at least one location on the structure remote from the rectifier where the influence from the rectifier on the structure-to-soil potential is discernable;
f) placing a remote monitoring unit at the selected remote location;
g) measuring the structure-to-soil potential with the remote monitoring unit;
and
h) comparing the structure-to-soil potential measured by the remote monitoring unit with the results from step d).

6 more elements

Dependencies are inferred from the claim text.

Cathodic protection remote monitoring method and apparatus

Life of this patent

Cathodic protection remote monitoring method and apparatus

Life of this patent

Abstract

Claims47