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MassiveProng MassiveProng is offline
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Default Calibration Of Electronic Equipment In The Home Workshop

On Sun, 04 Mar 2007 10:11:09 GMT, Robert Baer
Gave us:

Here is a good "trick" to measure low currents with your DVM.
Make a switchable shunt box with (at least) the following full scale
ranges: 200nA (shunt resistor 1.11 megs), 2uA (shunt resistor 101K),
20uA (shunt resistor 10.0K), 200uA (shunt resistor 1.00K).
Put a twisted pair of leads (red, black) with banana plugs (red,
black) running out of the box via a small grommet, to plug into your DVM
set to the 200mV scale; a pair of (red, black) banana jacks with 0.75
"spacing is mounted on the box for your test leads.
Hint: add to the legend the parallel resistance of the system
(200nA/1M, 2uA/100K, etc) as a reminder of the resistance of this
current meter scheme.
Added hint: the 200MV scale is good for 20nA full scale, just
remember the meter resistance is 10 megs.



Tell us, oh master... what does placing a 1,1 meg resistor in
series with a circuit's power source do to the voltage presented to
the circuit?

Shunt resistors are typically less than an ohm. Show me where
ANYONE uses a 1.1 meg resistor os a current shunt.