Close Interval Potential Survey (CIPS)

CIPS survey in process

These surveys are carried out to test the overall effectiveness of the Cathodic Protection system and involve taking potential readings along the whole pipeline route at equidistant spacing. On Impressed Current systems, On and Off potentials are usually recorded, taking both readings every metre. Current interrupters are set up in synchronization with the datalogger commonly at a switching ratio of 4 : 1 On : Off to prevent pipeline depolarisation. A timing cycle of 0.8 seconds On and 0.2 Off is commonly adopted.

Cath-Tech GPS Hexcorders and Current Interrupters are utilised for the survey and all collected data is downloaded to allow interpretation and presentation in typical spreadsheet programs.

To ensure correct interpretation of data in areas of stray current interaction, a simultaneous "static" pipe to soil potential is always recorded. This is done utilising a second Hexcorder or Smartlogger at a representative test location during the survey.