Clamp on / Probe thermometer recommendations ...?

[D_Hailsham]

Its just that they are not accurate enough to be useful for professional applications where its important to have an accurate measurement.

That's a very sweeping statement! It all depends on the quality of the instrument. You can't expect a £20 one to work to the same tolerances as a £200 one. Maplin are selling one for £50 which has a stated accuracy of ±2%.

Hospitals now use IR thermometers instead of mercury ones; and I'm sure they wouldn't have changed if there was any doubt about their accuracy - after all a temperature of 101°F is OK but 103°F is getting dangerous.

 

[Agile]

The instruments are quite accurate but as you yourself posted, the emissivity varies so widely that their usefulness is virtually zero for most heating measurements.

Hospitals use them because a non contact instrument does not spread infection.

I find mine are quite repeatable and useful for the mouth. I expect most mouths will be very similar.

Tony