Non-destructive measurement of CDP coatings inside hollow car body parts

In the automotive industry, the anti-rust warranty has become an important hallmark of car quality. Particularly in hard-to-reach areas such as the cross beams and pillars of the steel car body, specified tolerances for CDP coating thicknesses must be ensured, because in these areas, corrosion can proceed long undetected.

Modern car bodies are usually protected from rust with a primer coat applied by cathodic dip painting (CDP). Until now, it was not feasible to measure the coating thickness inside the hollow parts without destroying the entire car body. Common practice has been to dismantle random car bodies for spot-checking of these hidden areas. This approach carries a very high cost and makes systematic, real-time quality control more or less impossible.