Handheld Thermal scanner accuracy and the analogy to Encircled Flux fiber testing accuracy

Part of our new reality is being scanned at entrances of our work places and Malls with the now ubiquitous handheld Thermal scanners. A particular experience recently had me thinking of how accurate these scanners really are and our easy acceptance of their results. In my experience the first scan yielded a 31.1 Degree Celsius reading (Obviously I wouldn't be typing this if True) where after my second reading came out to 39 Degrees, also quite obviously not true as I was feeling quite chirpy that day. This could be attributed to improper training and/or inferior equipment which beggars the question of when do we accept the results of any measurement device?

In my field this becomes abundantly clear when dealing with Fiber Optic Networks that have evolved to require much higher bandwidths than in the past and when testing with incorrect methodologies/equipment at which point does it become pointless to do testing which amounts to nothing more than random readings?

In terms of testing Multimode links the tight Loss budgets required to give assurances on 40Gbs is set at 1.9dB ! the days of being able to have inconsistent and variable readings should be a thing of the past. Luckily testing standards have kept up and using Encircled Flux compliant test equipment and cords you should be able to stay within a 10% measurement variability well below the 40-50% fluctuations observed in the field with classic modal conditioners such as mandrels.

 Below is a real world example of a link giving 2 different Loss readings using a non Encircled Flux testing setup, a 1dB difference becomes big when you only have 1.9dB to play with.

 If your links are not being properly tested you could just as well be using a handheld thermal scanner to test as the results will be just as worthless an exercise.

 For more info feel free to reach out or comment as I would love to hear similar stories or analogies.