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How Digital Multimeters Work

  1. May 28, 2010 #1
    How exactly do digital multimeters measure things like potential difference, electric current, and electrical resistance?
     
  2. jcsd
  3. May 28, 2010 #2

    mgb_phys

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    They really only sense voltage. They measure current by putting the current through a small resistor and measuring the voltage accross it.

    They measure the voltage with an analog-digital-converter (ADC), there are a few different types but basically they are a source of different fixed voltages and a an amplifier to compare each fixed voltage with the measured voltage until they are are equal - then use that number.
     
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