This is not AVR related, but I am looking for all tips and tricks available to achieve a high insulation resistance between conductors in a circuit for some automatic safety-test equipment. The tester in question measures leakage resistance of a finished product from live/neutral to the chassis using 500V DC.
The problem is that the tester, followed by a relay switching matrix, followed by test leads reads about 500Megaohm when unconnected to the product, and the product must pass a test at several hundreds of MOhm more. Quantifying the "no-load" leakage accurately enough to do a parallel resistors calculation is impossible since the reading at "no-load" varies wildly.
The way I see it is that there are three leakage components in parallel, one in the tester, one in the relays and one in the test leads. The relay matrix and the test leads have at least 1.2GOhm individually as tested by a different device (full scale reading) while together they are somewhere between 800MOhm and 1GOhm. I cannot measure the leakage of the tester directly since I don't want to connect two outputs together....
A dessicant in the enclosure for the switching matrix did not help much.... :cry:
Is there any genius here who feels he's capable of offering a few ideas to a frustrated guy? :x