CP coupons and soil corrosion probes (SCPs) can be effective tools in applying CP criteria under challenging operating environments, such as cross-bonded systems or in high resistivity soil environments.

CP coupons are used for measuring polarized ("off") or depolarized (100 mV) potentials on pipelines and other structures, and are useful in situations where these type of potentials cannot be measured easily. This is usually in situations such as cross-bonded systems or structures in fluenced by interference from CP systems not controlled by the main protected system operator, or if it is not practical to simultaneously switch off numerous sources of CP current connected to the pipeline being tested.

SCPs are used to measure the metal corrosion rate, and are connected to the structure so that they receive the same level of CP as the structure. Thus even if the measured potential reading on the structure is not at the minimum required level, the corrosion rate measurement (mils per year, or microns) can be used as an alternative criterion to asses CP effectiveness. Low levels of polarization in high resistivity soils, or erroneous potential readings due to poor soil contact are examples of situations where SCPs can be useful.

 FOR ENQUIRES PLEASE DROP YOUR EMAIL AT dsa@tiaano.com/dsasupport@tiaano.com