[volt-nuts] Best way to measure micro Ohms

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 28 September 2017 at 19:17, ed breya <eb at telight.com> wrote:

> Hmm. Alternating the direction of the current repeatedly and processing
> the results - sure seems like that is fundamentally an AC measurement too,
> despite using DC measurement equipment.
>
> Ed


I guess the point is current/voltage can be measured accurately before the
direction is changed, whereas that's less so with AC. But I don't need
great accuracy in trying to sort out if there are contact resistance
problems caused by things such as copper slip, or aluminum oxides. I need
to measure very low resistances, but not with great accuracy.

For me at least, I have no Fluke 5520A, or low resistance meter.  The
Agilent programmable DC power supplies I have are not designed for
precision measurements.

But the lock-in amplifier I already had, and the audio amplifier was cheap.

Sometimes you have to make do with what you have, or can justify buying.

Dave