Originally Posted by
BobL
Good point and I have thought of this and doubt they are under much stress.
The resistors are rated at 1W.
The tester has 250, 500, 750 and 1000V test settings.
At least 2 x 1MΩ resistors in series are always in use
The highest test V setting used is 750V so using V^2/R so power would be 0.28W.
Even at 1000V, power would be 0.5W, but I don't use this to check the meter.
Like I said its not meant to be a definitive but rather an indicative test. If they were breaking down due to exposure to the tester voltages I would expect their resistance to change over time but they're still reading the same as when I first set them up. I don't use my tester all that often, maybe 6 times a year but it sure is handy to have one at home.