Majid Nosouhi - Majlesi Branch, Islamic Azad University
Mohsen Ashourian
Hamid Nazemi

Corrsion  is one of the most important problems which underground gas pipelines is facing it . Cathodic protection systems are dynamic systems that use electrical current to control corrosion. According to the existing standards there are different methods for evaluating level of cathodic protection  and coverings underground metal pipes.  One of the most practical methods is the close interval potential survey (CIPS).The efficiency of this method is very dependent on the quality of measuring parameter during the inspection.   minimising all the error source , either during the inspection or when interpreting  the data is vital. In this research CIPS method is analyzed and by optimizing synchronization of  the Interrupter devices  to decrease the errors during the CIPS test, in evaluating of cothodic  protection level and covering  the gas transmission underground metal pipes  provides a significant improvement.

Cathodic protecticn, CIPS, GPS, Interrupter