High impedance voltmeter

Discussion in 'General Electronics Chat' started by doctordiode, Apr 5, 2011.

  1. doctordiode

    Thread Starter New Member

    Apr 5, 2011
    Am new to electronics. The high impedance voltmeter is analog right? How high does the voltmeter reading go? Is it only 9 volts? I see see the Tlo82 Op amp but not the other Op amp in the circuit?
  2. SgtWookie


    Jul 17, 2007
    We don't know what schematic or project you are referring to, as you did not provide a link to it.
  3. Jaguarjoe

    Active Member

    Apr 7, 2010
    The impedance of a simple analog voltmeter depends upon the sensitivity of the meter movement and the range the meter is set to. For a typical 20,000ohm/volt sensitivity VOM (Volt-Ohm-Milliamp Meter) On the 1v range, the input impedance will be 20,000*1 or 20,000 ohms. On the 100v range, it will be 20,000*100 or 2 megohms. Some really cheap meters could be 1000 ohms/volt. For meters with signal conditioning circuits, like a digital multimeter (DMM) the input impedance is normally a constant value, like 10 megohms irregardless of its range.
  4. eblc1388

    AAC Fanatic!

    Nov 28, 2008
    It will be different for different meters. Better check for confirmation.

    My Fluke has 10MΩ input impedance at most DC ranges but only 2.3MΩ at 300mV range.