I am in the UK. I have a £20 digital multimeter and would like some advice. The meter is a Maplin model PG10B (order code GW18U)(Q1) Under "DC CURRENT" my user guide says, "voltage drop: 200 mV". Is this the disturbance in a circuit when measuring DC current?
(Q2) If so, then does that 200 mV figure mean that the potential difference for the rest of the circuit will be reduced by 200 mV once I have interrupted the circuit and inserted my meter for DC Current measurement?
(Q3) Isn't that figure of 200 mV rather high? I mean, if I use the 2 mA or 20 mA scale in an electronics circuit powered by a 1.5 volt cell then a 200 mV drop in the circuit is very significant.
My real need is to measure current while charging a AAA NiMH cell.
When I set my multimeter to measure DC Current and insert it in the circuit, the charger's light fails to come on!
It's as if the prescence of the meter is disturbing the circuit too much.
The voltage of my uncharged cell might typically be 1.1 volts and the charger says it delivers up to about 120 mA.
(Q4) Is my multimeter simply too low-spec to measure current in this application?