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Another multimeter Q

Discussion in 'Electronic Repair' started by Eric Vey, Dec 19, 2004.

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  1. Eric Vey

    Eric Vey Guest

    I have an old Fluke 8020B and no manual. I don't remember how I got it,
    but I use it all the time around the house.

    After ~20(?) years of owning it, I finally notice that it has a range
    that I didn't notice since I didn't have a reason to use it . . . 200nS
    and 2mS. What is this? And what can I use it for?
     
  2. NSM

    NSM Guest

    | I have an old Fluke 8020B and no manual. I don't remember how I got it,
    | but I use it all the time around the house.
    |
    | After ~20(?) years of owning it, I finally notice that it has a range
    | that I didn't notice since I didn't have a reason to use it . . . 200nS
    | and 2mS. What is this? And what can I use it for?

    Did you look on the Fluke website?

    The two ranges may output pulses (unlikely), or measure the time period of a
    waveform - similar to measuring frequency.

    N
     
  3. Eric Vey

    Eric Vey Guest

    I googled quite a bit before I posted here.
    I didn't realize that Fluke had their old manuals online since google
    didn't pick them up.

    Okay, it is for testing conductance. It says I can test for leaky diodes
    and transistors. That's about all it says.
     
  4. Jerry G.

    Jerry G. Guest

    I am not sure, but going from memory, this may be a Siemens scale. This
    has to do with very high impedance readings.

    The Siemens scale is based on conductivity, derived from inverse
    resistance. This would then would be nS = nano-Siemens, and mS would be
    milli-Siemens.

    This link is about a dedicated Siemens meter, just to give an
    explanation of what the Siemens scale is about.
    http://www.trifield.com/HighResistance.htm

    The Siemens scale is used for testing insulation factors, and very high
    resistance values. There is also an instrument called a megger that is
    used for testing very high resistances of materials, and especialy the
    break down resistance of insulator materials. There are meggers that
    also use very high voltages for the testing, in order to determine the
    if the insulation material will easily break down and start to condcut
    under use with voltage applied.

    Jerry Greenberg
    ============
     
  5. Asimov

    Asimov Guest

    "Eric Vey" bravely wrote to "All" (19 Dec 04 17:26:17)
    --- on the heady topic of "Another multimeter Q"

    EV> From: Eric Vey <>

    EV> I have an old Fluke 8020B and no manual. I don't remember how I got
    EV> it, but I use it all the time around the house.

    EV> After ~20(?) years of owning it, I finally notice that it has a range
    EV> that I didn't notice since I didn't have a reason to use it . . .
    EV> 200nS and 2mS. What is this? And what can I use it for?

    Conductance. The unit of conductance is the Siemens. Conductance is
    simply the inverse of resistance i.e. 1/R. It used to be called the
    MHO. Conductance is a useful parameter for measuring very low value
    resistances in motor windings, PCB traces, and other conductors. It is
    also useful to figure out parallel resistors by adding up their
    conductance but my solar scientific already has a handy 1/x key.

    A*s*i*m*o*v

    .... Resistance Is Futile! (If < 1 ohm)
     
  6. NSM

    NSM Guest

    | I am not sure, but going from memory, this may be a Siemens scale. This
    | has to do with very high impedance readings.
    |
    | The Siemens scale is based on conductivity, derived from inverse
    | resistance. This would then would be nS = nano-Siemens, and mS would be
    | milli-Siemens.
    |
    | This link is about a dedicated Siemens meter, just to give an
    | explanation of what the Siemens scale is about.
    | http://www.trifield.com/HighResistance.htm
    |
    | The Siemens scale is used for testing insulation factors, and very high
    | resistance values. There is also an instrument called a megger that is
    | used for testing very high resistances of materials, and especialy the
    | break down resistance of insulator materials. There are meggers that
    | also use very high voltages for the testing, in order to determine the
    | if the insulation material will easily break down and start to condcut
    | under use with voltage applied.
    |
    | Jerry Greenberg

    ISTR that some early Flukes had those functions.

    N
     
  7. Adam

    Adam Guest

    S = A / V
     
  8. Adam

    Adam Guest

    Or in other words: S = Ω^−1
     
  9. Guise

    Guise Guest

    You are close with this one, and the last one.

    1 S = 1 / Gohm


    From: http://www.trifield.com/HighResistance.htm

    A NanoSiemen is 1 divided by a GigOhm. It's the same as one NanoAmp per
    Volt. A PicoSiemen is one PicoAmp per Volt, or the inverse of one TeraOhm.
    Therefore, a 1 GigOhm resistor will have a conductance of 1 NanoSiemen, and
    a 1 TeraOhm will have 1 PicoSiemen. Note that because one is the inverse of
    the other, then 2 TeraOhms corresponds to 0.5 PicoSiemen. The two
    conductance ranges therefore cover the following ranges of equivalent
    resistance: The first conductance range goes from .001 x 10-9 Siemens (=1012
    Ohms or 1 TeraOhm) to 19.999 x 10-9 Siemens (=5 x 106 Ohms or 5 MegOhms),
    and the second conductance range goes from .001 x 10-12 Siemens (=1015 Ohms
    or 1000 TeraOhms) to 19.999 x 10-12 Siemens (=5 x 109 Ohms or 5 GigOhms).

    --


    Greetings,

    Romeo E. Albert
    ============
     
  10. Graham

    Graham Guest


    Hang on a sec.

    We are talking here about the reciprocal of resistance aren't we?
    When I was studying electronics in about 69/70 we were taught that 1/OHM was
    a (wait for it) mho (pronounced MOW)

    The strange thing is we were supposed to be using SI units and I think I
    would have remembered if the term Siemens had been mentioned, because of the
    famous German corporation.

    I wonder when Siemens became the excepted term over mho, at least here in
    the UK.
     
  11. budgie

    budgie Guest

    nanoSiemens (mhos) etc.

    If you are really keen, hit the Fluke website. I searched for a manual for an
    8024A a couple of years back, and IIRC it wasn't there but an email reaped a
    reward.
     
  12. Jerry G.

    Jerry G. Guest

    This has nothing to do with the famous German company called Siemens. Maybe
    the Siemens company was named after the famous German scientist who's last
    name was Siemens. I cannot remember his first name.

    Siemens is a measurement of conductance for materials that have very high
    resistance. It is another standard, that is more precise than ohms for the
    ranges required. In standard electronics applications that are used in every
    day home appliances and A/V equipment, Siemens are not a measurement that is
    normally used.

    This measurement may be applied to insulating materials that would be used
    in high voltage systems, specific types of transformer design, and in high
    powered RF systems, just for an expample. It is just another standard. There
    is nothing political here.

    --

    Jerry G.
    =====



    Hang on a sec.

    We are talking here about the reciprocal of resistance aren't we?
    When I was studying electronics in about 69/70 we were taught that 1/OHM was
    a (wait for it) mho (pronounced MOW)

    The strange thing is we were supposed to be using SI units and I think I
    would have remembered if the term Siemens had been mentioned, because of the
    famous German corporation.

    I wonder when Siemens became the excepted term over mho, at least here in
    the UK.
     
  13. Jim Adney

    Jim Adney Guest

    They are conductance measurements in milliSiemens and microSiemens.
    They are used for resistances greater than those usually measured with
    most DVM.

    I have one of those meters, but I never got used to those
    measurements.

    -
     
  14. Adam

    Adam Guest

    Both the Bureau Interational des Poids et Mesures (BIPM)and the United
    States National Instute of Standards and Technology (NIST) call this SI
    derived unit "Siemens" and make no mention of mho. After some searching
    it would seem that the unit was named after Ernst Werner von Siemens a
    German electrical engineer in the mid 1800s [3].

    [1] http://www1.bipm.org/en/si/derived_units/2-2-2.html#siemens
    [2] http://physics.nist.gov/cuu/Units/units.html
    [3] http://chem.ch.huji.ac.il/~eugeniik/history/siemens.html
     
  15. << EV> After ~20(?) years of owning it, I finally notice that it has a range
    EV> that I didn't notice since I didn't have a reason to use it . . .
    EV> 200nS and 2mS. What is this? And what can I use it for?

    Conductance. The unit of conductance is the Siemens. Conductance is
    simply the inverse of resistance i.e. 1/R. It used to be called the
    MHO. Conductance is a useful parameter for measuring very low value
    resistances in motor windings, PCB traces, and other conductors. It is
    also useful to figure out parallel resistors by adding up their
    conductance but my solar scientific already has a handy 1/x key. >>

    Asimov-

    The advantage of the conductance scale on a digital meter, is that when it goes
    over-range, the resistance is low enough to be measured on one of the
    resistance scales. If the resistance scale goes over-range, your 1/x key won't
    do you any good!

    To the best of my memory, the lowest conductance reading on my 8020A, is equal
    to 5000 Megohms when you take the reciprocal.

    Fred
     
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