On Friday, 17 April 2020 20:49:29 UTC+1, Martin Brown wrote:
On 17/04/2020 19:48, Harry Bloomfield wrote:
What's the difference between the usual DIY IR guns and the ones which
they are using (Asia) to check body temperature in the epidemic?

The main difference is that the ones intended for use on humans or
animals are calibrated for the emissivity of human skin which isn't all
that close to being a black body for thermal radiation.

For precise none contact work you put a black sticker on the target that
has the right emissivity for the measurement device you are using. But
for mass screening it is easier to fiddle the detector to match "skin".

The Chinese don't bother with any of that. They just pick out anyone with higher temp reading than the rest.


NT