My question should answer why so much 'leakage' was measured
at the pipe. Insulation stopped convention heat transfer.
But the pipe was doing radiated heat transfer. Therefore
little heat radiated by pipe appeared as much heat on the
tester. Instructions for the heat detection device should
discuss this if true. Above is a hypothesis that would also
explain why fury animals measure lower. Fur convents heat but
does not radiate much.

To better understand what I am asking, first bone up on a
concept called black surface radiation. Simpler concepts of
conduction, convention, and radiation were (in my time) taught
in public school science. How does the manufacturer discuss
this?

"P. Thompson" wrote:
It does run into problems in the areas that the FAQ's on those devices
mention. Shiny aluminum, for instance.

Also, in the case of skin temperature or the temperature of furry
animals I've noticed it tend to read lower than one would expect
perhaps since it just reads the very surface of the object that it
hits which can be quite cool.

Not sure if I can answer your question but I wonder if the level
of accuracy you're asking for is necessary for pinpointing leak
locations.