Choose a Holiday Detector

• Confirm spark testing is allowed for the coating system and the governing specification — NACE SP0188, ASTM D5162 or ASTM G62 — including its voltage-selection clause.
• Start from a trustworthy dry film thickness reading, then match the detector's voltage range to the thickest coating you realistically expect to test. A unit that covers only part of your range forces a second purchase.
• Choose the electrode set for the geometry you inspect. The right brush, spring or rolling electrode for pipe internals, tank floors or complex weldments is what separates a usable field tool from one the inspector has to work around.
• Then compare the two product pages below and pick the detector that best fits how your team carries out the work.

Both cover the full 0.5–35 kV spark-testing range, so the practical difference is how each one sets the test voltage and fits the way you work.

• PoroTest 7 — a handheld, probe-based detector with three interchangeable probes covering coatings from 0.03 to 11.3 mm and a backlit display showing the set voltage, coating thickness and a live pore count. Its thickness-matched voltage presets and light 1.4 kg control unit suit routine porosity surveys on pipes, tanks, vessels and hulls (conforms to DIN 55670).
• PosiTest HHD — a standards-driven detector adjustable in fine 10–100 V steps, with a built-in voltage calculator that sets the test voltage from any of 11 international standards once you enter the coating thickness, a certified on-board voltmeter and a supplied calibration certificate. It converts between a standalone stick and a belt-fed wand, handles builds up to 20 mm and works on conductive and semi-conductive substrates including concrete — the pick where formal compliance (ASTM D4787 / D5162 / G62, ISO 29601, NACE) and an audit trail matter most.

The buying decision is still method-first, but once spark testing is confirmed, the choice becomes which of these two detectors is the better fit for the job. If the coating build or specification rules out spark testing, neither of these detectors is the right final answer.

Do not force a product choice until the inspection method is clear. If the substrate is not conductive, if the coating has not reached the right condition for continuity testing, or if the project requirement points to a different inspection approach, this page is not the right final decision point.

Open both product pages above when you are ready to compare the two holiday detectors we sell for spark-testing work, then continue with the model that best matches your inspection requirement.

• High-Voltage Spark Testing for the method background behind this detector choice.
• Voltage Selection and Coating Thickness for the coating-build logic that should be confirmed before detector selection.