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Corrosion assessment and wall thickness measurement using radiography is a well-established and cost-effective inspection method. It is particularly indispensable when inspecting pipelines that are insulated, whose surfaces are not directly accessible, or when UT inspection cannot be used for other reasons. In principle, there are two methods: tangential measurement and densitometric measurement, the latter being explicitly based on Beer’s attenuation law.
The practical value of both methods depends on the precision and reliability of the measurements and on the surrounding conditions (which are influenced, among other factors, by wall thickness, pipe diameter and the scatter factor). The scatter factor itself is affected by irregularities and deposits.