I can't stop playing with this cheap, no-contact, IR thermometer

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Note: If someone suggests where to shove that thermometer, they may not be entirely sincere. While the suggestion may sound scientifically interesting, do not follow it.

I have the FLIR One thermal imager attachment for my iPad. I am experienced in these matters.


I took mine outside in the winter to go as far as to see where the house was leaking heat so I could find the holes under the siding. I love mine for everything.


Well, does it?


At this point, I imagine the BoingBoing offices to be an enormous warehouse containing every electronic toy ever made. We’re lucky they ever write at all.


So that’s who the “top men” are!


Do NOT use this on a steak. It will only show the surface temperature, which is mostly meaningless. You need a temperature probe to determine the interior temperature. About 125°F is perfect for a rare steak. I use this ThermoWorks model, just $19. ThermoWorks makes excellent commercial-grade products. Their ThermoPen is an industry standard, and is what they use on America’s Test Kitchen.


I missed an opportunity! I got one of these (or something very similar) over the winter, but I totally forgot to measure the heat leakage on the house. And, now it’s actually pretty warm. Silly me!

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How well does it work? Did you get the gen.1 or gen.2 (80x60 or 160x120)?

I am about to get one for android (and connect it to a raspi).

I have one and remember, it’s not medical grade, it is off by a couple degrees. Useful for just about everything except checking YOUR temperature.


Gen 2. I’m actually very surprised that the resolution is as low as 160x120. It seems much higher, but that’s probably because of the second camera being VGA quality. (The second camera takes a visible light image, traces the outlines of objects and blends them with the infra-red, to make it much easier to interpret what you’re seeing.)

It works VERY well. It’s a gadget that works BETTER than promised, thanks to all the software options. (Different color and black & white filters, the ability to take exact temperatures, good options for saving images, and the ability to slide between visible an infrared light on those images.)

One thing I should learn is to lock the sensitivity. (It DOES have this option.) Otherwise every picture (or every time you re-point the camera) is scaled so that there’s a full color range from extreme hot to extreme cold. So two images will both show extremes even when conditions are very different.


BTW, the heat was not being radiated from the back of my freezer as I expected. It was being radiated from all sides. So I cleared some space around the sides to increase efficiency and save energy.

I have one of these…I don’t think it’s all that accurate.

For example, I used it to check the temp of my water, straight out of the kettle, and it says 140° F, but the water is definitely hotter than that, because it still made perfect coffee, which requires a temp of 190°+

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i have two of these and they’re not that accurate at a distance. the IR radiates out and will really only provide an average temp over the surface.

i was wrong

at 1 foot the IR circle is about 12 inches across, at 3 feet it’s 36 inches, at 5 feet it’s 60 inches. so if your coffee mug is 5 feet away your getting the average-ish temp of the mug and the surrounding ~50 inches.

here’s the diagram from amazon

and yes the raccoon does have a fever.

they are great for cat toys, and checking the average temp of a wall, spot temperature if you can get close enough, or the surface temp of a bottle of milk for baby
and excellent for verifying temperatures inside fridges, freezers, frying pans, stoves and grills.


I bought a laser thermometer from Radio Shack when they had their going out of business sale. Works great for testing pans of hot oil for frying, as well as a cat toy. Do not mix the two.


The main question in my mind being, “Where the fuck did @beschizza go and what the hell is he up to now?”


They are also thrown off by shiny surfaces and color. We have industrial IR temperature meters that sell for around $200, that are much more accurate, but we still mark a shiny spot with black electrical tape or a Sharpie to get a better reading. These things were designed for measuring moving equipment like bearings where accuracy is not as important. We always use thermocouple probes on any important measurements.

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I have one that looks just like this and I don’t have that problem. I checked on nearly boiling water, and also compared against a sous vide water bath. It might be a couple of degrees off but certainly nothing like 50 degrees. Maybe your unit is busted?

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Both Monty Python and Indiana Jones have sought the Holy Grail. Maybe it was his turn.

Personally, I doubt I would have made it beyond the Castle Anthrax.

Can someone please give us a mash-up of the Monty Python & Indiana Jones grail quests?


The ratio is 12:1 not 1:1. At 1 foot the IR circle is 1 inch, and at 5 feet it is 5 inches.