So maybe things are starting to degrade?
The closing times, with the caveat the contact bouncing is not allowed for, look consistent:
Group 1 was using the house power supply (13.8V) where after it was shifted the the shed for two runs (groups 2 - 20). Then, with hot weather, the last run (groups 21-30) was back in the house where the temperature extremes are smoothed out by air conditioning.
Contact resistance also looks consistent though the presence of my phone near the test board when in the house would explain some of those outliers in groups 21-30.
However, opening times appear to have changed. There is a very tight distribution of opening times and an upward trend for groups 21-30. Groups 21-30 was when the R was halved from 1.35ohms to around 0.7 ohms. That means the current on contact closing has increased.
The capacitor internal resistance is probably now a factor and if I was being thorough I would measure the wave-forms with a digital oscilloscope to derive the current at contact close.
Suffice to say it looks to be the first evidence of degradation. It only took some 2.6 million cycles of increasing abuse. Another run "as-is" appears warranted to see if the trend of slower opening times continues. And some measurements of the current at contact close is planned.
73's
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