chainsaw cylinder temperature?

On Thu, 11 Jul 2024 21:45:08 -0400, "Jim Wilkins" snipped-for-privacy@gmail.com wrote as underneath :

Have you a fin painted (HT) matt black to measure on? Otherwise your reading with IR maybe low if looking straight at Al? Running rich will help cool it down a little .. Sorry no experience here on actual running temps! C+

On Thu, 11 Jul 2024 21:45:08 -0400, "Jim Wilkins" snipped-for-privacy@gmail.com wrote as underneath : ...

Have you a fin painted (HT) matt black to measure on? Otherwise your reading with IR maybe low if looking straight at Al? Running rich will help cool it down a little .. Sorry no experience here on actual running temps! C+

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I also have thermocouples and a thermal imager. Generally on a heatsink the imager shows a temperature spread greater than the error from not adjusting for emissivity, I've left it at the default 0.98 on the IR thermometer and drill a small hole for a K thermocouple at the indicated hottest spot in the rare case that I need more accuracy. Typically the place damage will occur is hidden internally anyway, so comparing IR readings to known values for similar conditions has to be enough. On power semiconductors a base-emitter or other diode voltage drop at or corrected to minimal current is a good indication of actual internal device temperature.

Unlike my Stihl the Husqvarna 350 has sufficient torque at part throttle to cut well, and doesn't heat over 300F. Problem solved.

On Fri, 12 Jul 2024 07:51:13 -0400, "Jim Wilkins" snipped-for-privacy@gmail.com wrote as underneath :

Thanks for posting Feedback, always useful! Yes I would have used pyrometer too.. I have my IR at 0.94e as default! Glad you are sorted.. C+

Thanks for posting Feedback, always useful! Yes I would have used pyrometer too.. I have my IR at 0.94e as default! Glad you are sorted.. C+

------------------------------------ Here is a take on paint vs the oxide layer:

Anodizing a heat sink is less of an issue. The anodization layer is much thinner than paint (a few micrometers in aluminum, for instance), so it presents a much lower thermal resistance than paint would."

I use black tape to optically measure the temperature of my walls and window film, to compare them to interior walls and search for correctable heat loss. For electronics and motors the IR thermometer and imager show patterns of temperature rising and stabilizing, relative but not actual values, I trust only a thermocouple in a well for that. Usually temperature difference or rate of change are all I need to know, since the temperature that will cause damage is often uncertain.

If accurate results are important I record the thermocouple data with a PC-connected TP4000ZC multimeter calibrated to melting ice and boiling water. The output file can be changed to .csv and imported to a spreadsheet to correct observed offsets. This is for retired hobby use, to approximate the professional lab instruments I had used at work.