Close Interval Potential Survey-CIPS
In order to analyse the external corrosion of buried pipelines, pipe/soil potential measurements are made. Pipe/soil potentials are normally measured at fixed test points spaced about 1 km to 5 km along a pipeline. However, reliable information about the status of CP of thepipeline between these test points is unknown since measurement is only valid at the reference electrode location.
High local differences in soil resistivities, interference and other effects may cause corrosion at intermediate locations even having good potentials at the test points.
Therefore the necessity to decrease the distance between succesive potential measurements yields more accurate information concerning the CP-conditions on the pipeline and hence a „close-interval“ or an „intensive“ measuring technique was developed with potential measurement in steps of 5 m or less over the line.
Reasons to use closed interval potential survey - CIPS
It is impractical and uneconomical to measure pipe/ soil potentials manually at closeintervals of 5 m along a pipeline. Recording these results and plotting them by hand especially for a long transmission pipeline system,uses lots of time even when using strip-chartrecorders for potential measurements. Therefore a quick and reliable system has been developed.
CIPS overcomes these problems by automatically recording, storing, calculating and displaying the potential data. The data is given in table and graphical forms by a microcomputer for this purpose.
The MoData2 is used for field recording of pipe/soil potentials and voltage drops in cathodic protection measurements. The measured potentials are displayed. Pipe-tosoil potential data are recorded in the internal memory of the MoData2, Multifunction Instrument.
4 measuring methods are directly integrated into mobile software package:
- 2-electrode method
- 3-electrode method
- Adding-up method
- IFO-method
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