Radio Controlled Interruption of Rectifiers for Polarization Testing

Abstract The application of cathodic protection has significantly reduced the probability of pipeline corrosion failures. However, the criteria used to determine cathodic protection adequacy may be leading to over protection of pipelines and may even be responsible in part for long range damage to protective coating systems. An alternative criterion can be used but requires the measurement of both the polarized and rest potentials present on the pipeline. Use of an alternative criterion may lead to lower levels of cathodic protection current. This could result in fewer rectifiers operating at lower outputs. This would produce savings in capital costs for new installations and maintenance costs for existing equipment. Measurement of polarization potentials tends to be either labor and time intensive or require more sophisticated data collection equipment. Automated equipment currently available for polarization testing requires computerized voltage reading equipment that produces readings that can not be easily verified with standard voltmeters. The purpose of this test was to determine if automated polarization readings could be taken with standard voltage reading meters by remotely controlling multiple cathodic protection rectifiers over a company radio system.