Re: Fluke calibration


"Dave Curtis" <dbaudiotech@xxxxxxxxxxxxxx> wrote in message
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On Fri, 3 Oct 2008 10:41:19 -0400, "Phil S."
<psymonds_no_spam@xxxxxxxxxxx> wrote:


"Stephen Cowell" <scowell@xxxxxxxxxxxxx> wrote in message
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"Rich Koerner" <richk@xxxxxxxxxxxxx> wrote in message
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Stephen Cowell wrote:

"Rich Koerner" <richk@xxxxxxxxxxxxx> wrote in message
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Stephen Cowell wrote:

"Phil S." <psymonds_no_spam@xxxxxxxxxxx> wrote
...

I put a number of different resistors on it. In the low range
(22z,
50z,
100z, 125z, 150z, 250z) it's consistently 20-25 ohms high and in
the
higher ranges it seems to do a little better, where I guess that
small
a
variance isn't as noticeable.. That looks like a calibration
error
to
me,
but I don't know much.

Try replacing the low-measurement fuse... these can
be damaged without failing completely. As a short-
term troubleshooting test you can foil-wrap it and see
if your ohms come back down... don't run with it
like that unless you want a dead meter.
__
Steve
.


Steve, that is really bad advice. Tin foil
NOTHING!!!!!!!!!!!!!!!!!!!!!!

Use the Tripplett 9045 to measure it!!!!!!!!!!

It's not in a high-current location... it is a protection
fuse, meant to go when you ohm wall current or a
charged cap. Jeez, don't have a cow, Rich.


Yo!!!!!

There is a *suspected* input resistance that is the cause of a low
resistance reading error.

You suggest this fuse, for having this resistance.

Then, USE an OHM Meter and MEASURE IT!!!!!!!!!!!!!!

If the fuse is the one I'm guessing, then when
it fails it's not constant... the granules are partially
burnt, so you get a non-linear resistance effect.
You can't just use a 1/2A slo-blo, it has to be
that special silly granular fuse, it's the only one
fast enough to protect the meter yet low enough
ohms to not affect the reading. When they don't
get fully blown, they go ohmic, in a non-linear
way. If someone's put a regular 1/2A sloblo
in there it could have the same or similar symptoms...
temperature sensitivity, ohmic, etc.

The easiest way to verify that the measurement
fuse is not the problem is to bypass it. I've
troubleshot giant industrial burners and other
expensive equipment with a jumper wire... it's
a standard practice when you know conditions
are controlled enough to allow it. That's why
I told him not to run the meter with the fuse
shunted.

Simple test... if the measurement is still off
with the fuse shorted, then there's bigger
problems. If it works good, then you need
that $5 fuse.
__
Steve
.


The existing is an MDL type fuse. It looks like it's got a rope wrapped
around the thingy [1].

[1] thingy: technical term for the part of the fuse that goes open when
things go bad. What the heck is it called, anyway?


The Element.

-DC

Now that you've told me, I'm not sure I really wanted this info 8>)


.

Relevant Pages

  • Re: Chrysler quality
    ... Check fuses with a load testing device such as a test lite, not an ohm meter. ... measure the resistance in ohms using an ohm meter. ... When Glenn said "it is possible to ohm out a faulty fuse", ...
    (rec.autos.makers.chrysler)
  • Re: Fluke calibration
    ... Try replacing the low-measurement fuse... ... There is a *suspected* input resistance that is the cause of a low ... USE an OHM Meter and MEASURE IT!!!!!!!!!!!!!! ... ohms to not affect the reading. ...
    (alt.guitar.amps)
  • Re: Fluke calibration
    ... Stephen Cowell wrote: ... Try replacing the low-measurement fuse... ... USE an OHM Meter and MEASURE IT!!!!!!!!!!!!!! ... ohms to not affect the reading. ...
    (alt.guitar.amps)
  • Re: Fluke calibration
    ... Try replacing the low-measurement fuse... ... There is a *suspected* input resistance that is the cause of a low ... USE an OHM Meter and MEASURE IT!!!!!!!!!!!!!! ... ohms to not affect the reading. ...
    (alt.guitar.amps)
  • Re: Fluke calibration
    ... Try replacing the low-measurement fuse... ... There is a *suspected* input resistance that is the cause of a low ... USE an OHM Meter and MEASURE IT!!!!!!!!!!!!!! ... ohms to not affect the reading. ...
    (alt.guitar.amps)