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Homework Help: Multimeter accuracy

  1. Mar 9, 2016 #1
    1. The problem statement, all variables and given/known data
    Which multimeter is more accurate?

    2. Relevant equations

    3. The attempt at a solution
    Which multimeter is more accurate, one that is ±1%+2 or one that is ±2.5%+2

    I don't know how to read it, is it the higher percentage one that's more accurate or the lower percentage one?
    I think it's the lower percentage one but I'm not too sure.

    Also, what does the +2 mean? Does that make much of a difference?
  2. jcsd
  3. Mar 9, 2016 #2


    Staff: Mentor

    Lower would be more accurate.
    I don't know what the +2 means, either. Where did you see this? Can you post a link or a picture?
  4. Mar 9, 2016 #3

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  5. Mar 9, 2016 #4


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  6. Mar 9, 2016 #5


    Staff: Mentor

    The explanation isn't very clear, and I think they might have a typo. If the actual voltage is 100 V, an error of +/- 1% would give a range of indicated values between 99.0 V and 101.0 V. The + 2 has to do with the least significant digit being off by 2. They go on to say it could be as low as 99.8 V or as high as 101.2 V. I believe the low value should be 98.8 V, not 99.8 V.
  7. Mar 9, 2016 #6
    Yea, I notice that now, that's why I was so confused. I couldn't find a clear explanation online so I came here. Thanks for clearing it up.
  8. Mar 9, 2016 #7


    Staff: Mentor

    My comment is consistent with the link that nsaspook provided. (Look on the tab with Accuracy.)
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