I want to buy a non-contact thermometer to have around the house for measuring my kid's temperature. Also, I do have other uses for an industrial IR thermometer which I don't own. Given that the non-contact IR ones you can buy at the pharmacy work on the same principle as the industrial thermometers, I was thinking of just buying an inexpensive industrial IR thermometer like the Uni-t ut300b or something similarly priced. Will I be able to measure body temperature accurately with a thermometer like this? Also, are they good for measuring the temperature of liquids, like water flowing from a faucet?
No. The industrial thermometers are not enough accurate unless you are spending big time. Some handheld units get close to required accuracy in 500 to 1000 usd price range.
"Industrial" ir-thermometer like Heitronics KT19 or TRT II would be enough accurate but i guess good quality ear thermometer is a bit cheaper than 10-30 k usd
Yes and no, the body measure thermometers use a bolometer that is selected to have a good response at around 35-45C, and is calibrated to be accurate with a black body radiator ( the human skin in the ear and mouth is a pretty good black body approximation) to within 0.05C. the industrial sensors are only going to have 0.5C resolution and up to 2C of error at that point.
Using them to measure also requires knowing ( or taking a guess) at emissivity of the surface, you only get an accurate temperature with a surface that is the same or similar emissivity as the one it was calibrated to. Some you can set the emissivity, but your accuracy is poorer then, and the fixed units can have a very large error.
Buy a cheap body contact thermometer or three for use with the children and adults ( they are very cheap and quite accurate), and use the IR for other things. otherwise look for a used IR thermometer for body use on whatever auction site you have locally.
Those IR ear thermometers are awfully inexpensive for what you get to be looking for an alternative.
For fevers you'll want to measure the internal body core temperature (hence the ear, mouth or ...). The industrial IR camera will only be able to measure skin temperature which will vary more. You could obviously point it at the ear but would be pretty hard to get a reading from inside the ear, even if you centred it you wouldn't be sure of how accurate it would be.
Surprised this hasn't been bumped this year...
I always think it's funny when google answers my question with an EEVBlog page
My experience with a "liberated" Flir E4 is that the temperature resolution is more than sufficient to detect elevated skin temperatures (you can set temp windows to get a nice colour gradient in the relevant temp range), yet the absolute calibration lacks. What that means: You could very well use it to spot "hotter" individuals in a crowd of people that are supposed to have normal body temperature. You cannot do this reliably by using the E4 to measure spot temperature individually. The internal calibration that the E4 is doing once every few minutes will adjust absolute temperature easily by + / - 1K, so the readings will spread by this amount. I cannot tell for other thermal cameras, but I assume that in the lower price range, the situation would be similar.
Oh, just noticed, that a very old one... Why bumping this stuff, I guess it rather belongs in the "Thermal Imaging" section anyway.