Mastercool 52224B Dual Temp Infrared Thermometer

I shopped pretty hard for this item. It has a 1:15 spot size which is nice, and unlike other units it goes down to -76F. The plug-in on the side for a thermocouple probe (probe not included with this model) is a plus. It comes in a blow-molded plastic case. Buy the one Amazon sells directly and get free shipping!

Physically the unit is designed well. The battery compartment door is a bit stiff, and the trigger spring is rather hard, but these are minor quibbles. The main large temperature display always shows the current IR measurement, and holds it when the trigger is released. The unit stays on for maybe a minute or so afterward, including the backlight (if enabled).

There are lots of display modes for the secondary smaller temperature display and they are easy to access via the rubber keys under the display. Min and max are recorded over the measurement period in which the trigger is held in. Average is a true running average, and not the simple average of min & max. Probe temp is shown when a probe is plugged in and prob temp is selected for the secondary display. Emissivity is adjustable from 0 to 100, so you can calibrate the IR reading with the probe reading if desired.

My unit came with the pointing laser and backlight off by default, not sure why, but they are easy to enable via the rubber buttons. There is also a "always on" mode that might not be obvious, as the laser does not come on, even if it is enabled. So if you find that your unit is not automatically turning off, perhaps you put it in this mode (there is an icon on the display too).

As a test I tried adjusting the emissivity to around 75 so that my body temperature would read correctly when scanning my forehead and reading the max over 5 seconds or so. This gave reliable readings one day, and unreliable the next, so you probably can't use it as a replacement for a fever thermometer. That was just an experiment, and I wasn't expecting it to work reliably in that fashion.

It's fun to check the temp of things on the stove & in the fridge & freezer, and it works well for finding cold air infiltrating our house. Great item, everyone should have one of these things in their science kit / tool box!