Holiday Testing Voltage Formula

They are effective for coating thicknesses of 500.

Holiday testing voltage formula. The test results confirm the criterial voltage value of as 3862 2002 is applicable to dlfbe. In this example then the test voltage of 11 180 v can be used since it is less than the breakdown voltage of the material 16 800v. A low voltage wet sponge tester may be used without damaging the coating but can produce erroneous readings.

Procedure methodology a. There are two main types of holiday testing devices. Low voltage holiday detectors.

The level of test voltage used depends on the type of fault you are trying to find and the electrical properties of the coating material. Reference code and standard awwa c203 is 10221 sec 7 1 7 2 4. It is used to locate discontinuities in a nonconductive coating.

To prevent damage to a coating if a high voltage spark tester is being used the total film thickness and dielectric strength of the coating system shall be considered in selecting the appropriate voltage for detection of discontinuities. They show that that subsequent coating holiday testing in accordance with as 3894 1 using a detector with constant dc voltage output and with the voltage set to 65 of the specified values in as 3894 1 will result in reliable detection of coating. Scope the holiday test is to be carried out for 100 of the wrapped and coated pipes using portable low amperage adjustable voltage and pulse type holiday detector employing an audible signalling device.

Use a dc voltage detector not pulse. As a general rule the nace standard sp 02 74 has been found to work well in most cases. Dc holiday detectors expertise.

Low voltage wet sponge testing 3 1 equipment 3 1 1 a low voltage wet sponge tester is an electronic device powered by a self contained battery with voltages ranging from 5 to 90 v dc depending on the manufacturer s circuit design. Low voltage and high voltage holiday detectors. A simple way to test what voltage a coating can withstand is to apply the voltage with a brass brush probe applied then slowly wind up the voltage note.