BS EN ISO 2376:2019 pdf free.Anodizing of aluminium and its alloys – Determination of breakdown voltage and withstand voltage.
7.1 Flat or near-flat surfaces 7.1.1 Preparation of test
Before the test, the test specimen shall be kept in the test environment over I h. Measure and record the temperature and relative humidity of the environment in which the test is taking place. Unless otherwise specified, carry out the determination at room temperature and less than 65 % of relative humidity. Place the test specimen on the contact plate (5.2) in good electrical contact with it, for example by using an earthing clip. Alternatively, make contact to the basis metal using the contact probe or clip. Connect the contact plate or contact probe or clip (51) and the electrode probe (5..f) to opposite poles of the secondary winding of the transformer (5.2), and place the probe on the test specimen so that the force exerted on the coating is 0,5 N to 1,0 N (5.).
7.1.2 Breakdown test
Starting at zero, increase the voltage uniformly at a rate not exceeding 25 V/s until the voltage drops suddenly (indicating breakdown voltage of the coating). It is necessary to clean the contact surface of the probe after any breakdown has occurred, and it is essential to return the voltage to zero after each determination and particularly before cleaning the probe. Carry out a minimum of five tests and record the lowest value and the mean value obtained. Alternatively, ascertain whether or not any value falls below a predetermined breakdown voltage.
7.1.3 Withstand voltage test
Starting at zero, increase the voltage uniformly to the specified voltage and maintain that voltage for the specified period of time. If electric breakdown does not occur within the specified time period, then the voltage indicates the withstand voltage. If the voltage drops within the specified period of time,
then that is due to electric breakdown. It is necessary to clean the contact surface of the probe after each determination, and it is essential to return the voltage to zero after each determination and particularly before cleaning the probe. The voltage and the period of time should be specified by the customer and the anodizer.BS EN ISO 2376 pdf download.