At minimum, you would need to compensate for the ESR of the new 450V cap you
introduced in series into the test leads in order to still get an accurate
reading. The diode clamps sounds like a more effective way to protect the
ESR meter to me since test voltage is kept below the bias voltage so they
don't affect the calculated ESR.

Bob

wrote in message
ups.com...
That would seem to beg the question if one were simply to replace that
cap with say one with a 450V working voltage, would the diodes then be
unnecessary? Lenny