faulty analogue multimeter

[qfeng]

I suspect my analogue multimeter is faulty. It gives wrong reading. When I measure a AA sized battery in the 10V range, I get 1V reading. In 2.5V range, I get 0.5V reading. If in the 0.5V range, I only get 0.1V reading.

Is it faulty? Can it be fix? Thx in advance.

[EdwardM]

Hi

if your multimeter has typically a 100uA meter movement for full scale, this means that at each of the ranges you mention, 10V, 2.5V and 0.5V there will be a resistance in series with the meter of 100KOhms, 25KOhms and 5KOhms - representing a varying load on the AA battery that you are measuring.

It's unlikely that three independent ranges would be faulty (the only realistic common factor being the meter movement) so, the most reasonable explanation to me would be that your are measuring a dead battery which has insufficient current capacity to move the meter.

Try measuring a new battery, which should give a reading of about 1.5V~1.6V.  You could also try measuring the voltage across a forward biased diode (0.6V~0.7V).

Hope that helps

Ed