On 03/01/2013 09:34, harry wrote:

I think it only took 3 or 4 tweaks in length to get the meter calibrated
to the load being drawn.

So how do you know it is accurate?

You'd need to define the degree of accuracy required.

For my own needs calibrating to a know fixed load was good enough.
+ or - 10% would have been fine so more precise "tuning" wasn't needed.

Running the PSU on the fixed load for +60 minutes soak test (to check
overall stability of unit and heat dissipation of transistors /
auto-cooling fan etc saw no deviation in meter reading which pretty much
ruled out inaccuracies from varying shunt temperature which presumably
remained pretty constant.

Everything is relative to exactly what level of accuracy the OP actually
needs, which I don't believe has ever been stated.

Cheers
Pete@

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