Not really sure where to post this...hoping to find a health professional who knows about this.
I've just acquired an infrared non-contact thermometer and am trying to understand how to use it. The model is Guangdong IT-122 but it looks the same as many others ranging in price from £11-50.
The thing that concerns me is that there is clearly a calibration function which the manual just says something like "can be used to compensate for differences in room temperature, measuring distance, skin differences etc." The effect is to add or subtract up to 2C from every reading.
It's absolutely silent about how to actually do the calibration. But this seems to be a completely crucial step if it is to be relied on for deciding whether someone (e.g. office visitors) may have a COVID-caused fever.
I do also have a small thermal imaging camera which also measures temperature, so potentially I could compare readings using that. But the reviews on Amazon say things like "wonderfully accurate straight out of the box"
I'm not even sure if using a calibration lab is worthwhile if there are so many environmental factors that can influence the reading. All in all it makes me rather sceptical about the value of taking these measurements.