On 07 Sep 2005 00:00:55 GMT, Ian Stirling
wrote:

Could you explain (and I'm an aging
electronics engineer remember) how / why that would be different from
reading any current in a cct (on a DMM) please?

Sorry, I was not being clear.
Of course it's not different.
My point was that it's not a 'real' measurement, it's affected by the
test instrument to a great degree.
On 2mA, it'll read .25mA, on 200uA, 30uA, and on 20mA 20mA. (or so).

Ah, gotcha ..

I've found it really handy in the past to measure leakage currents,
when the uA range won't quite cut it.
A 3.99 meter with a 1M input impedance will resolve down to 100pA when
set on voltage.
(care does need to be taken that you're getting accurate measurements.)

Good tip ;-)

Cheers Ian ...

T i m