Fw: Re: [Amps] meter internal R value, quick and easy.

[skipp isaham]

Hi Gary, 
-
I do use a Fluke brand multi meter with the set up I described, I 
should have mentioned that.  The circuit layout does work 
pretty well for me. 
-
I have noticed that even the small Fluke Meter internal 
resistance can and does change the loop current, more 
than one might imagine. 
-
I don't like using Multi or Ohm Meters direct onto unprotected 
meter movements.   The classic Simpson 260 meter will 
damage a 200 uA movement on the higher resistance 
positions.  
-
cheers
skipp
-
--------- Forwarded message ----------
From: Gary Schafer <garyschafer@attbi.com>
That won't work exactly right. If the pot in parallel with the meter
matches
the meter resistance then the sum of the meter and parallel resistor is
1/2
of what the meter was alone. That will increase the series circuit
current
from what it was with just the meter so there will be more circuit
current
than exactly 1/2 the original current in the meter and the resistor. If
you
set the pot for 1/2 scale  meter reading the pot and parallel resistor
will
each have a different current because the total series circuit resistance
has
changed and the circuit current is different.
It would work if you had a second meter to monitor the series circuit
current
and readjusted the series pot to maintain the same circuit current.
73
Gary  K4FMX


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