Can I use a IR temp gun to tune air fuel

There are far too many variables to tune the fire just using a IR gun.

Here's a thread on O2 sensors...
https://www.hearth.com/talk/threads/wide-band-o2-sensor-for-control-of-combustion.11836/
There's even more reasons this wouldn't work other than what was covered in this thread.

If you had a Harman you could get a DDM and plug in to check things out. Bixby has computer plug for almost thirty readings. Hard to use just temp to tune a stove and what spot to read from? Harman and Bixby use exhaust stream readings but also know the fan and auger speeds and rates.

Maybe a bachrach test kit. Used on oil and gas furnaces. You can def get an idea of the smoke content in the flu. As well as draft and temp.

Doug Doty said:

I was not wanting to point the IR gun at the fire itself, I have just been using it on a point on top of the stove that is repeatable. It worked for the different settings and I could detect a change in pellet brands. I am just trying to determine if the highest tuned temperature reading for a given feed rate and fan setting is the most efficient way to run the stove and if it is indicative of a proper tune.

Click to expand...

The IR gun will provide a general idea of how much heat a stove is putting out at a given setting. I have done this using several reference points on the stove. The problem I find is that the flame goes up and down because pellets are not all the same size and do not feed evenly. Even with the same stove settings some brands will have small short pellets that feed faster (more heat) than longer pellets (less heat); longs mixed with shorts also causes ups and downs. Flame is a pretty good indicator as is ash buildup which can be caused by either pellet or stove deficiencies.

I agree with HD41j'ai made test with different brands of pellet stove and at the same adjustment for each test and I saw difference up to 3 hours with a bag of 40 lbs. I had no more than 1 degree of difference in the room with a bag to another and the outside temperature was the same.

you certainly could have fun with one

I used my IR gun to test different pellet brands and had good luck doing so. I took readings in 3 different places at 10 minute intervals over 60 minutes then averaged the readings. I found some pellet brands made a 40 degree (f) difference in the stove surface temp. I never thought about tuning the heat output using the same method but I will definitely give it a try.