Test method Porosity Testing with High Voltage standards: AS 3894.1, ASTM D4787, ASTM D5162, ASTM G62, EN 14430, NACE SP0188, NACE SP0490, NACE SP0274
The test method is based on the fact that all electrically insulating coating materials have a much higher dielectric strength than air.
For testing, one sets the corresponding test voltage for the coating thickness on the POROSCOPE®. Alternatively, one can also enter a testing standard and coating thickness. The POROSCOPE® will then automatically set the corresponding test voltage. One connects the specimen with the earth cable and moves the electrode slowly over the surface to be tested. If the electrode passes a crack, a short voltage drop will occur – a sparkover. An optical and acoustic signal indicates the pore, and the pore count is increased by one step.