Accelerated stress test for old electrolytic capacitors

[conductivity]

"The most commonly accepted method is based on the thermal stress over the rated temperature of the capacitors, which is based on the application of the Arrhenius’ law to the chemical reaction speed (10)."
https://epci.eu/aluminium-electrolytic-capacitors-accelerated-lifetime-modeling/

Good overview of accelerated stress testing of electrolytic capacitors in the link. Have you tried to use extra heat for measuring old electrolytic capacitors with an LCR meter? New ones are made to handle their rated temperature for many hours without drifting out of spec.

Yet, do you think it would be a good idea to use a hairdryer and thermometer or something like that when measuring old electrolytic capacitors? In other words, do you think it is likely to reveal significant data compared to ambient/room temperature? I am only thinking about hobbyists like me knowledgeable that companies specifically don't like to waste time/resources.

[TheMG]

Bad idea, short term heating won't do much. Capacitors should be measured at room temperature. ESR tends to actually decrease and capacitance increase with higher temperatures, so a cap that is actually out of spec could appear good when heated up.

This is also part of the reason sometimes a device will work fine as long as it remains on, but if turned off long enough to allow it to cool to room temp and then powered back on suddenly it fails.

[Siwastaja]

Indeed, understand the fundamental difference, almost orthogonality of causing aging, or measuring aging.

High temperature is used to make capacitors age faster, but the effects of increased ESR is best seen at low temperatures.

[jwet]

As the last poster said, ESR actually improves with temperature.  One of the electronics repair you tubers I've seen looks (Mr. Carlson?) probe around caps with a soldering iron and see if the unit starts working magically with he heats them up- kind of the opposite of freeze spray.