On 30/05/2011 08:47, RussellMc wrote:
> If I'm right (ask the student), in  Bob's circuit the divide ratio is
> 11:1 so 1% untrimmed resistors in the divider*may*  typically produce
> a 10% error.

Or you measure also with accurate bench meter and put a calibration=20
factor in SW.

Then limitation original test gear, temperature and ageing drift.
--=20
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