From: charlie@xxx.net   
      
   On Fri, 12 Jul 2024 07:51:13 -0400, "Jim Wilkins"    
   wrote as underneath :   
      
   >"Charlie+"  wrote in message   
   >news:89k19jlledmumfehiklp9jbvmhjumukecm@4ax.com...   
   >   
   >On Thu, 11 Jul 2024 21:45:08 -0400, "Jim Wilkins"    
   >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+   
   >   
   >---------------------------   
   >   
   >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.   
      
   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+   
      
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