Sciencemadness Discussion Board

Infrared IR Thermometers

agorot - 20-2-2010 at 21:28

I've been wanting to get one of these devices for quite some time now for a variety of different applications, but if anyone out there already has one, I'd like to get some advice.

I'm mostly curious about the emissivity values that a thermometer uses to measure the surface of a substance. Some thermometers come with an adjustable emissivity value, but others come with a (usually .95) fixed value. This is to adjust for the different amounts of radiation that different substances emit. Does adjustable emissivity really matter though? How much error does the non-adjustable emissivity create?

Also does the ability to accurately measure an object degrade at the extreme ends of a thermometer's range?

Thanks for your help

chemrox - 21-2-2010 at 00:14

I have two, one fixed and one with adjustable emissivity. The one with settings gives more accurate readings with glassware than the fixed one. I don't recall the specific parameters involved. They're trick to use and generally give ballpark answers. They are handy for avoiding burns and guessing when something is ready to come over.

agorot - 22-2-2010 at 16:24

How much more accurate is the nonfixed one? Is the fixed one within 5 degrees? If I were to measure a piece of hot glassware at 600 degrees, how accurate would your fixed one versus your non fixed one be?