Waveforms, or scopes, have been around in the world of close interval potential surveys (CIS/CIPS) for decades, but are often underutilised. A lack of knowledge about their usefulness is the main cause. The name associated with the data comes from the equipment used to obtain it. The reading is taken with an oscilloscope-like device (hence ‘scope read’), which displays and records the waveform of a set period. Many modern CIS instruments have this ability built in, making it easy to view and record a waveform during a survey.
Elizabeth Nicholson, Corrosion 2015, Paper 5675
Describes a fuzzy logic model intended for quantitative risk analysis to the integrity of buried pipelines. The proposed approach correlates data from combined CIPS+DCVG coating surveys to the soil resistivity, in order to define an indicator that expresses the corrosion susceptibility at a given coating defect location. Inputs used in the mathematical model include: DCVG defect severity, CIPS pipe-to-soil “OFF” potentials and local soil electrical resistivity
Elizabeth Nicholson, Corcon 2014 Corrosion Conference & Expo, Mumbai
Many types of surveys are done to allow the operator to assess the condition of a pipeline. Two surveys are essential to any pipeline integrity management program, coating integrity and cathodic polarization. Coating integrity is investigated by generating a pulse on the pipeline, then walking the pipe to locate any voltage gradients in the soil.
Elizabeth Nicholson, B.Eng.,Presented at: POLSKI KOMITET ELEKTROCHEMICZNEJ OCHRONY PRZED KOROZJĄ STOWARZYSZENIA ELEKTRYKÓW POLSKICH w WARSZAWIE September 19-21, 2012 in Jurata, Poland
Coatings prevent corrosion by creating a barrier between the structure and the electrolyte. Cathodic protection works by changing the potential of the structure to interfere with the corrosion process. Both work together to protect the structure. Surveys can be done to evaluate the condition of the coating and of the cathodic protection.