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What can a analog volt meter do that a digital one can't?

Discussion in 'General Electronics Discussion' started by danny davis, May 12, 2012.

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  1. danny davis

    danny davis

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    May 9, 2012
    What can a analog volt meter do that a digital one can't?

    What kind of tests or checks is good to use for an analog volt meter? to test for what?
     
  2. davenn

    davenn Moderator

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    Sep 5, 2009
    nothing really

    a digital one is much more versatile
    sample and hold
    some can output data to computer either real time logging or just as a block of data
    for future reference

    Dave
     
  3. danny davis

    danny davis

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    May 9, 2012
    So the meters impedance changes what kind of tests or measurements?

    it changes the resistance reading of the circuit or component you're measuring? because of the meter loading? and the meter is in parallel with the circuit?

    Analog meter impedance vs digital meter impedance?
    Analog meter loading vs digital meter loading?
     
  4. Rleo6965

    Rleo6965

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    Jan 22, 2012
    In analog tester I can compare transistor leak or gain and compare it to another transistor for correct replacement. Very useful with push pull transistor. Using RX10 Ohmmeter range. Very old technique.

    You can't do this with digital tester.
     
    Last edited: May 12, 2012
  5. danny davis

    danny davis

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    May 9, 2012
    In analog tester I can compare transistor leak or gain and compare it to another transistor for correct replacement. Very useful with push pull transistor. Using RX10 Ohmmeter range.

    How can you test the transistors leak using RX10?
    How can you test the transistors gain using RX10?
     
  6. davenn

    davenn Moderator

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    Sep 5, 2009


    a lot of digital meters have transistor testing functions built in :)


    the impedance of the meter affects readings taken. This is mainly when measuring resistances in circuit.
    In general analog meters are low impedance and will affect the reading by loading down the circuit. Compared to digital meters that are high impedance.

    long ago an analog meter was available that was treasured by service technicians. This was the VTVM, Vacuum Tube Volt Meter, and had a high impedance input

    cheers
    Dave
     
  7. alfa88

    alfa88

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    Dec 1, 2010
    I find resistance checks on diodes and transistors with digital meters inconclusive. Analog meters exel in that respect. IMHO
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    Is this your homework?

    I own an analogue multimeter, but I can't remember the last time I used it. I think I grabbed the probes to use with another meter.

    That may indicate something.

    It can do better to display a rough average of a rapidly changing signal, or to give an intuitive feel of the rate of change of a slowly changing signal, but that's also why many digital meters have a pseudo analogue display as well.
     
  9. danny davis

    danny davis

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    May 9, 2012
    Why would i want to do resistance checks on diodes?
    Why would i want to do resistance checks on transistors?

    Wouldn't an oscilloscope show you that better than an analog meter? or what is the difference?

    I'm still confused about using an analog meter to measure transistor leakage and gain and how to do it
     
  10. Rleo6965

    Rleo6965

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    Jan 22, 2012
    For NPN
    Set Ohmmeter to RX10.
    Place wire clip to Emitter and other end of the clip to ( + ) RED Probe for Japanese Analog Meters. Then place ( - ) Black probe to the collector with your hand touching or holding both the collector and Black Test Probe. A slight movement or high resistance should of meter means good . A low resistance means leaky or shorted. Needle passing halfway of the meter.

    Now while your holding the collector touch with your other finger the Base of transistor. Meter needle should swing to lower resistance. The lower the reading the higher gain. Then compare this to another transistor for gain or leak comparison. If the meter did not move. Transistor was open.

    For PNP

    Reverse the Test Probe.

    The idea here was your hand acting as high value resistor ( 1 meg. ) between Collector and the Base. Therefore placing forward bias to the Base of Transistor.

    I just accidentally learn it by experimentation 40 yrs ago when I was a student in Electronics. That's why I call it old technique. :D:D:D
     
    Last edited: May 12, 2012
  11. weird_dave

    weird_dave

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    May 9, 2012
    'Scopes aren't always so easy to hold if you're away from the bench.... And probably more expensive to replace when dropped :)

    I also like analogue meters for checking small batteries, the resistance of the meter when measuring volts can show that the battery has problems by seeing that the needle drops down. Digital meters have such a high input resistance that this doesn't happen.
     
  12. jackorocko

    jackorocko

    1,284
    1
    Apr 4, 2010
    I still use an analog meter to check batteries to see if they are charged. Again using the resistance setting. Throw the battery on the probe, a quick visual of the needle is all you need to tell you if the battery is good, partially good, or bad.

    I can do a couple hundred batteries in a few minutes this way. Works well when your significant other brings home about 20 batteries a week or so. One of the perks working in a hospital. When your heart patient leaves after a night in the hospital those brand new double AA batteries need replacing in that meter. Pocket them and bring them home. My kid will finish them off in her toys. :)
     
    Last edited: May 12, 2012
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