Holiday Detectors

Q: When should I use a low-voltage wet sponge detector versus a high-voltage spark tester?

Low-voltage wet sponge detectors (like the PosiTest LPD ) are used exclusively on thin coatings under 500 µm (20 mils) where high voltage might arc through sound coating. High-voltage spark testers are required for thicker protective barrier coatings exceeding 20 mils.

High Voltage Holiday Detectors

Low Voltage Holiday Detectors

PCWI Holiday Detectors

DeFelsko PosiTest HHD

DeFelsko PosiTest LPD

ABQ Industrial offers an advanced range of professional Holiday Detectors and porosity testing instruments from industry-leading manufacturers including DeFelsko, PCWI, and ElektroPhysik. Engineered for corrosion control engineers, pipeline inspectors, tank liners, and quality assurance inspectors, these non-destructive instruments locate microscopic pinholes, voids, cracks, and holidays in protective coating systems before premature corrosion can attack the underlying metal or concrete substrate.

Whether your inspection protocol requires low-voltage wet sponge testing on thin paint films under 20 mils, high-voltage continuous DC testing on heavy-duty pipeline coatings and storage tanks, or high-voltage pulse testing on damp or conductive thick membranes, our catalog delivers the exact voltage regulation, safety triggers, and standards compliance (ASTM G62, ASTM D5162, NACE SP0188, ISO 14654, ISO 8289) required for certified anti-corrosion inspection.

F.A.Q.

When should I use a low-voltage wet sponge detector versus a high-voltage spark tester?

Low-voltage wet sponge detectors (like the PosiTest LPD) are used exclusively on thin coatings under 500 µm (20 mils) where high voltage might arc through sound coating. High-voltage spark testers are required for thicker protective barrier coatings exceeding 20 mils.

How is the correct test voltage calculated for high-voltage Holiday Detectors?

Test voltage is determined by the specific coating thickness and applicable test standards (such as NACE SP0188 or ASTM D5162). Modern instruments like the PosiTest HHD feature a built-in voltage calculator where selecting the standard and entering coating thickness automatically calculates the required voltage.

Why is proper grounding critical during Holiday Detection?

A Holiday Detector completes an electrical circuit through the coating fault to the conductive substrate and back to the instrument earth clamp. If the substrate is not properly grounded to earth or if the ground lead has poor electrical contact, the detector will fail to register pinholes and flaws.