What about diff px testers. Why do they need to be calibrated for. If you have 80 on one side and 80 on the other you self calibrated. Basically the fique is irrelevant . If you have a leak you will hear it and the gague will show it. Move the prop and sometimes you will fix it extra cost for no outcome. Like 12months for locite wtf. Cause one ex raaf awi decided it would be a good thing.
Its unfortunately what you get awis that ate ex millitary and ex ailrines in casa. No idea at all.
Toot toot tootie pie