Holiday and Pinhole Detection

Checkline Europe's Technical Support 10 Jul 2026

Choosing holiday and pinhole equipment starts with a method decision, not a product one: is the coating a thick, high-build system that suits high-voltage spark testing, or a thin protective film that has to be checked with a low-voltage wet sponge? Get that right and the detector choice becomes straightforward; get it wrong and the test either misses defects or creates them.

This is the continuity check that gets scrutinised at coating acceptance — a pipeline survey, a tank or vessel handover, an offshore QC sign-off — where every holiday has to be found, marked and repaired before the asset goes into service. Once you know spark testing is the right method for the coating, the guide below moves you from that decision to a concrete detector.

1. Common Measurement Scenarios

You are most likely here if one of these sounds like your situation:

You already know the substrate is conductive and continuity testing is the right step — typically buried, immersed or chemically exposed coated steel.
You are inspecting thick dielectric coatings on a conductive substrate — FBE pipeline coatings, coal-tar epoxies, thick-build novolacs or tank linings above roughly 500 microns dry film — where high-voltage spark testing applies.
You need to confirm that coating thickness, coating type and the governing specification all support spark testing before buying, since the same project may need wet-sponge for one coat and spark for the next.
You want to move from method confirmation to a realistic product decision without reviewing unrelated coating-inspection tools.

2. Available Selection Guides

Choose a Holiday Detector compares the two high-voltage detectors we sell once you have confirmed spark testing is the right method — the route from method to a concrete product decision, covering voltage range, electrode set and workflow fit.

3. Supporting Knowledge Resources

If you would rather understand the method before deciding, start here:

Holiday and Pinhole Detection — when continuity testing is the right inspection method, and how spark and wet-sponge approaches differ.
High-Voltage Spark Testing — how the high-voltage method works and when it suits thicker coatings on conductive substrates.
Voltage Selection and Coating Thickness — why the test voltage has to be matched to coating build and the governing standard.