To begin, connect the signal return cable to an uncoated part of the substrate being tested, using the easy release crocodile clip. A 4m signal return cable is provided as standard, but if you’re testing on larger structures, a 10m cable is available. Either way, each signal cable is snag proof, so you can always move freely while testing.
Next, wet the sponge. This should be done with clean tap water, as it contains salts that allow it to conduct electricity. It’s important that you have an appropriate amount of water on the sponge before testing, as too little water will not conduct electricity and not locate any pinholes; whereas too much water will drip from the sponge and cover the surface under test, which can result in pinholes being detected in the wrong location.

So, to ensure the sponge is suitably wetted; first thoroughly wet the sponge, then squeeze out the excess - so the sponge is damp, but water is not dripping freely from it.
To maximise the efficiency of the Elcometer 270 Pinhole Tester, you can add a surfactant to the water. Using a surfactant will significantly reduce the surface tension of the water, allowing the moisture to penetrate the smallest of pinholes. For how much to add, simply follow the dilution instructions supplied with the surfactant.

With the sponge suitably damp, switch on the Elcometer 270 Pinhole Detector - keeping the sponge clear of the test surface.
The Elcometer 270 Pinhole Tester is available in either dual or triple voltage models. The dual voltage model can be set to 9V, for testing thin coatings up to 300 microns (12 mils) thick; and 90V, for coatings up to 500 microns (20mils). The triple voltage model can also test at 67.5V, the US standard test requirement.

Every time the pinhole tester is switched on or the voltage is changed, the Elcometer 270 Pinhole Tester automatically tests the calibration of the internal voltage and sensitivity.

With the calibration tested, you can now pass the sponge over the coated surface to test for pinholes. If the sponge passes over a pinhole, the Elcometer 270 Pinhole Detector will instantly alarm.
If you need to locate a pinhole more precisely, simply retest the area using just a corner of the sponge.