Probability Of Detection 

POD – Probability Of Detection – is a means of describing how well an inspection procedure can detect the required defects. The chance or probability of detecting a defect will lie somewhere between 0 (no chance of detecting a defect) and 1 (no chance of not detecting a defect). By assigning POD values to a procedure, it is possible to compare the effectiveness of different inspection techniques. Alternatively, POD values can be used as a target which procedures have to be shown to be able to achieve.

POD values have been widely adopted, particularly in the aerospace industry. More recently, they have found increased use on process plant as they allow the impact of inspections to be considered in fracture mechanic assessments and risk-based inspection analysis where the probability of failure of a component is assessed.

When using PODs, it is important to understand how the value was obtained, what procedure and defects it applies to and any other assumptions which have been made.

For more information on Probability of Detection see:
'Probability of Detection as a Quantitative Measure of Non-Destructive Testing End to End Process Capabilities', Ward D Rummel, Materials Evaluation, January 1998.

What the hec?! articles are not intended to be the definitive account on the topic or acronym in question. Readers’ comments and contributions are welcomed. Email: ndtnews@bindt.org