Cursitor Doom wrote:


Be aware that the ESR meters intended for service work are only good
for electrolytic caps ( regular aluminium and tantalum ) and
interpreting the readings correctly requires significant operator
knowledge and/or a similar electro to compare with.

...Or a table of expected values vs. voltage rating vs. capacitance -
which comes with the Peak meter.


** IME, such tables are far too vague and out of date for modern electros.

The goal in servicing & refurbishing work is to find electro caps that
are *on the way out* as well as obviously dead ones.

If in doubt, comparison with a the closest new electro available is a
good move.

Well maybe. But it'll slow the process down massively as it's not just
the capacitance that causes ESR values to change. As you well know.


** See page 9 of the Peak ESR meter user's guide.

http://www.peakelec.co.uk/resources/...erguide_en.pdf

The ESR values shown in the table up to 470uF are several times higher than normally found with new caps of the same ratings.

When servicing, the task is to identify electros whose ESR has risen significantly, indicating end of useful life. Cos most of the electrolyte that was there when new has escaped and evaporated.



..... Phil