N_Cook wrote:
D Yuniskis wrote in message
I think a PIR imager would have been helpful. Though not
sure if even that would have helped (though it probably would
for some types of failures)

I happened to be playing with the innards of a domestic PIR unit for hotspot
"divining". Not too sure whether it would be useable. Uses RPY96 6 to 14

Sorry, I meant *imager* (not just a "thermometer").
I.e., look at large areas and see different temperature
ranges in pseudo-colors.

"Gee, why is this section so 'red'?"

micron pyro and LM324 (.8 micron is red light) . Monitoring an lm324 output
for a small component 8 degree C over ambient, gave about 50mV swing up and
down of a nominal not too steady quiescent long term level. So if static at
2.3V would swing up to about 2.35 and then down to about 2.25 with a time
constant of a second or so , so again inconvenient. You have to scan across
as not a static process of generation of signal. There is a piezo effect as
well with the sensor so you would have to be very gentle in movement to
monitor 1 or 2 degree C over ambient. I shrouded the TO5 sensor with a 1.5
inch long dense foam rubber tube but matt metal maybe better, any thoughts?