Value drift over time
I was in the elctronic surplus bisness from the 60's to the end of the
century. Most people thought that
Allen-Bradleys were the gold standard. One cusomer complained and we
started checking samples.
They were all out of tolerance. A-B's speck sheet specified how to
measure. For a given resistance
range you applied a specified voltage and measured the current.
As an aside: In the 50's I ran across some carbon comp. resistors that
had been modified.
Apparently the person was short of cash or in a hurry. The person took
a CC and a triangular file
and raised the CC to the value neede.
CP
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