Which tool is commonly employed to discover breaks in a coating?

Eddy current testing is a highly effective tool for detecting breaks or discontinuities in coatings. This technique utilizes electromagnetic induction to create eddy currents within conductive materials. When a surface has a defect such as a crack or a break in the coating, the flow of these eddy currents is disrupted. This disturbance can be measured and analyzed, thus indicating the presence of faults beneath the coating.

Eddy current testing is particularly advantageous because it does not require direct contact with the coating and can be used on a variety of materials. This feature makes it suitable for non-destructive testing in many industrial applications, including the evaluation of coatings on pressure vessels, ensuring that any underlying issues can be addressed without damaging the structural integrity of the component.

In contrast, other methods like liquid penetrant testing are more suited for detecting surface-breaking flaws rather than issues specifically within coatings. Ultrasonic gauges primarily measure wall thickness and may not directly indicate breaks in the coating, while magnetic particle testing is limited to ferromagnetic materials and primarily identifies surface and near-surface defects rather than coating integrity. Each of these methods has its own application but for discovering breaks in a coating specifically, eddy current testing stands out as the preferred choice.