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Old 11-19-2015, 05:11 PM
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Username1 Username1 is offline
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Join Date: Dec 2009
Location: Orange County NY
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Quote:
Originally Posted by Findm-Keepm View Post
No effect at all. Think about it, when you put a milliammeter in the circuit to check the current, you are adding the DC resistance of the meter, which is several hundred ohms, and you still have 200 mA in the circuit.
I don't think this is true at all.... Resistance of 1 - 4 Ohms max,
Several Hundred Ohms and you strongly change what the meter is actually
reading. Most good meter movements are Micro-Ampers full scale, so reading
200Ma, the current handling resistor should be pretty small.

For a current reading meter to be highest in accuracy, it would have to present
as close to zero resistance to the circuit as possible..... Just as in measuring
voltage, the meter should present as close as possible to infinite resistance
as possible to the circuit.... That is why VTVM's and digital's are choice for
a lot of really accurate DC voltage use especially, because of high resistance
on input...

.
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Last edited by Username1; 11-19-2015 at 05:23 PM.
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