Measurement of gear tooth temperature while gears are running and after stopping

[SMKRe]

I would like to know the gear tooth temperature while the gears are running. I could not measure the temperature while gears are rotating.
I have measured gear tooth temperature after stopping the gears and cutting the lubricant oil (within 10 minutes ).
After stopping gearbox, the oil on gear tooth is wiped off and the temperature measured. I have observed the temperature rise of gears ( for some time after wiping off tooth) and then reduced again.
Is it acceptable to consider the temperature measured after gears stopping as the real time (gears running) temperature?

Kindly clarify this and suggest some methods to measure the gear tooth temperature accurately while gears are rotating.

 

[lucky-guesser]

How accurate do you need to be?

If the gearbox is greased then this wouldn't work but if there is a fair amount of oil movement, the oil should be close in temp to the gears. There are a number of tools you can add to a gearbox to measure oil temp, which may be representative of the gears themselves.

 

[TED7]

Take some measurements with an infra red based non-contact system (or thermal imaging, whatever) while rotating - record them.
Take some more measurements with a contact based system stationary - record those too.
Graph the two methods against each other.

You might find that the non-contact system is "close enough", or you might find that it has a fixed offset from the stationary temperature.

If it's the latter case, you just need to do some math each time to convert the non-contact temperature to the true temperature.