On Tuesday, March 10, 2015 at 1:35:29 PM UTC+13, Ron D. wrote:
Also 0.2 to 0.5 ohms is VERY difficult to measure without a 4 or 5 wire ohmeter or a 4 terminal measurement. Your test leads and internal meter connections can EASILY have 1 ohm of resistance each.

A way to measure low resistance values is to measure the current through the device and the voltage across it. You can add series resistance and measure the voltage across the known resistor and convert that to a current.

If I'm right, your meter is not capable of measuring 0.2 to 0.5 ohms.

Thanks Ron, but would the meter be correct enough to see a difference between 0.5 or 2.5? Or are both my measurements likely unreliable? If I adjust the ohm meter to 0 ohm while shorting the test pins, then a subsequent reading of 2.5 ohm should be in addition to the internal resistance of the leads etc, and therefore reasonably accurate? It's a pretty robust analogue meter.