In article ,
John Bachman wrote:

The Capacitor Wizard uses a 100Khz sinusoidal signal. The Bob Parker
design is as described - that is what is used in our Blue ESR meter.
Bob always represented that his method is the equivalent of a 100Khz
signal.

John-

I built one of your Blue ESR meter kits and am impressed with it.

Somewhere I read that there is an industry specification or common
practice, that requires ESR measurement to be made at 100 KHz. If it is
in fact a "standard" method, you should petition that standards
committee to agree that your method is equivalent.

As others commented, approximate methods for measuring ESR may be
adequate for detecting common failures. However, I do not think the Bob
Parker method is approximate. As long as there is no significant
inductance involved, it seems to be quite accurate. Try putting
resistors in series with low-ESR capacitors. Taking the low ESR into
account, the meter should measure close to the same value as when
connected across the resistors alone. I expect it will agree with other
methods of measuring the resistors. Certainly better than ten percent!

Fred