Here are the readings from my car today using a laser and digital thermometer. As you can see it was 88 degrees in Lauderdale-by-the Sea at 3:30 today. The 36 degree was laser thermometer pointing at outer ac vent, the 26.9 degree was laser thermometer pointed at internal ac duct, the 46.5 degree was digital. I think I would trust the laser thermometer more. These pics were taken at idle, the temp gets colder when driving. I would definitely recommend the electronic thermistor, without it my evaporator used to freeze up after driving about an hour. the digital may need to be calibrated.
An IR thermometer cannot be trusted at all unless you have set the emissivity correctly. A plastic piece at 27F and an aluminum piece at 27F will both radiate heat differently, so the thermometer must be manually set up for each one differently.
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