AC/DC Clamp Meter Altitude Limit

I'm putting together my toolkit and just got an AC/DC clamp meter. While reading the instruction booklet (since my identity is a secret I can admit that :D) I noticed that there is an altitude operating limitation of ~6500 feet. The property I have where the solar installation will be is at ~7500 feet. Any ideas why this type of meter would have such a limitation and what problems or skewed readings might occur if operated above the listed limitation?

Comments

  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    Re: AC/DC Clamp Meter Altitude Limit

    I can't imagine it making enough differenct to be significant, but I await more learned opinion with anticipation.

    T
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: AC/DC Clamp Meter Altitude Limit

    It most likely has to do with the high voltage range of the meter, where they rely on air, as the insulator. Maybe for the current shunt, where air needs to cool it. At less than 100v, I don't see how it can make much difference, unless the LCD display dries out.
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  • boB
    boB Solar Expert Posts: 1,030 ✭✭✭✭
    Re: AC/DC Clamp Meter Altitude Limit

    This has to do with decreasing breakdown voltage with decreasing atmospheric pressure, up to a point, that is, where it starts to reverse.

    Search for Paschen’s Law and curve.

    boB