"nicola" wrote in message
...
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)

http://www.maplin.co.uk/Module.aspx?ModuleNo=4402

(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.


One way round this is to use a stable adjustable PSU and adjust for the
required voltage *after* the current meter. If your circuit draws large
pulses, pad the supply rails with a hefty electrolytic.