Video: DIELECTROTEST – Operation
DIELECTROTEST step by step: safety, preparing the test vessel and electrodes, filling without bubbles, the test sequence, withstand testing and reading the printed report.
AI-generated video. The information must be validated by an Amperis engineer.
See the product page: Dielectric strength meter Dielectrotest
Video transcript
How to run an oil test, step by step, and what happens inside the instrument while it runs. This instrument makes 10 of 1000 of volts inside a box you can carry. Touching high voltage kills, so the rules are short and there are no exceptions. Two things before the first switch on. Let the instrument reach room temperature for at least 30 minutes, and check that the voltage selector and the fuses match your mains. Getting that wrong destroys the instrument.
Now open it up, at least on paper. Inside there is less than you might think: a chain that turns ordinary mains voltage into a controlled high voltage, and a chamber where the sample is tested. Follow the path. Mains voltage goes into a regulating transformer that a stepper motor turns, slowly and precisely. That gives the ramp. The high voltage transformer multiplies it and feeds the electrodes. When the spark jumps, the current rises, the detector sees it and cuts everything.
Now the part that decides whether your result means anything: the vessel. A dirty vessel gives a low reading, and you will blame the oil. Then the electrodes. Their shape and their separation are not free choices: the standard fixes them, and the instrument asks you which ones you fitted. Filling looks trivial and it is not. Pour slowly: a bubble sitting on an electrode will break down long before the oil does, and the result will be wrong. The front panel is deliberately plain.
A key switch, a screen, 4 keys whose meaning changes with what is on the screen, 3 lamps and a printer. The sequence on the screen follows the same order every time, and it asks only what it needs. What the instrument then does looks like this: a ramp, a breakdown, a pause to stir and let the oil recover, and the next ramp, as many times as the standard asks. There is a second kind of test.
Instead of looking for the breakdown, the instrument climbs to a voltage you choose and holds it, to see whether the sample survives. At the end you get the numbers that matter: each individual breakdown, the average, and the standard deviation that tells you how consistent the oil was. And to keep it honest over the years: calibrate it once a year, keep it dry, and never open it yourself. Insulating oil testing, from Amperis.
