I borrowed one of these non-contact thermometers to test the heat dissipation around a new fireplace I'm finishing. It worked so well that it had me running around my house measuring the temperature of lots of things that I'd often wondered about but had no way of investigating. For instance I was curious about the results of extra insulation I put in last year. I also found myself using the device to follow heat contours around the house. I could follow heat contours in the air by using this device to measure the temperature of the skin of my hand. This method made a rigorous investigation into energy conservation fun as well as informative.

One attribute of IR thermometers I really appreciated is their instantaneous response, even across a distance. Since the device is based on an infrared light sensor, there is no lag, no hysteresis (like a thermostat), no memory, no need to even be close to the surface being measured, which is a lot different from how I am used to thinking about temperature.

With the ST pro model it was like I could reach across the room and touch the wall in the back of the fireplace to see how hot the fire was getting. I discovered all kinds of readings that affected my fireplace design. For instance it was around 400 degrees near the gas pipe I was sealing with fireplace caulk. I found that it got to a max of 70 degrees above the fireplace where I was thinking of mounting a plasma TV; that it was a max of 100 degrees about a foot in front of the fireplace at the level of the hearth, and that there was a temp gradient of about 40 degrees to the side edges of the hearth. (I figure that gradient was probably not a steep enough to cause levels of thermal stress that would crack the slate I was planning to use for the hearth). However I was able to measure a much sharper gradient across the metal face of the zero-clearance fireplace, where I planned to mount tile with special heat-tolerant silicon adhesive (thus needing to confirm the max temp of the metal face at around 210 degrees after 2 hours of fire). And so on.

As a homeowner it may be hard to justify buying one, but as a nerd (and especially if I had kids) I want one around. For me it has something to do with an Internet-biased mentality -- I hear an obscure concept, or someone has a question, and I almost reflexively reach for Google. Now it's like that for my home. Is that frying pan at exactly the right temperature for pancakes? Wait, I can get the IR thermometer out of the kitchen drawer...

-- Rick Botman

Raytek Mini Non-Contact Thermometer
Model MT4
$45
Available from Amazon

Manufactured by Raytek