FP30 face temp vs STT

[Tater1985]

In light of some comments on another thread I thought that I would do some temp checking of my own on my FP30. Another user had made a comment about the STT vs. face temp on a PE Summit. He had noted that he was seeing approximately 100df difference between SST and the upper left face temp, with the STT being higher.

So I borrowed a Fluke 62 IR gun, which has adjustable emissivity setting. Based on research I was finding emissivity range of 0.94-0.97 for black paint and matte black finishes. I set the emissivity at 0.95 to take my temp readings.

Once my Condar Inferno stove top thermometer was up to about 450-460 I started taking readings. With the door cracked open and shooting right beside the Condar I was getting right around 450. What I found interesting was with the door closed and shooting in the exact same spot I was getting about 335-345. I did this multiple times with the same results. Even showed the wife to confirm I was not crazy.
With that being said, when taking that reading of 335-345 right next to the Condar with the door closed, the STT was about 395-405. I tried this several times as well and overall I felt fairly confident I was seeing about 50-70 degrees difference between my STT and the upper left face temp. I will say that I noticed the temps were about 20 degrees higher top dead center over the door. So I am wondering if this is a better place for the Condar?

Overall I would be interested in hearing thoughts on all of this. Especially if anyone can explain why the IR gun was reading 100+ degrees less than the Condar with the door closed even with the emissivity set correctly. And we have checked our oven temp with a couple thermometers and when I first got the Condar I threw it in the oven on a cookie sheet at 450 to check it and it was as close as I could ask for.



2018 Pacific Energy FP30

 

[Tater1985]

Has anyone with an FP30 used an IR gun to check STT thru their craftsman surround? I checked mine during the hot part of the burn cycle today with a pretty full load. I had both fans going to manage temps. My thermometer on the face was arpund 650, but the IR gun was showing 450 on the stove top. Curious if any other FP30 owners have any numbers to compare?

2018 Pacific Energy FP30

 

[begreen]

Has anyone with an FP30 used an IR gun to check STT thru their craftsman surround? I checked mine during the hot part of the burn cycle today with a pretty full load. I had both fans going to manage temps. My thermometer on the face was arpund 650, but the IR gun was showing 450 on the stove top. Curious if any other FP30 owners have any numbers to compare?

2018 Pacific Energy FP30

Was the blower running?

 

[Tater1985]

Was the blower running?

Yes i had the blower running.

2018 Pacific Energy FP30

 

[MAD MARK]

Yes i had the blower running.

2018 Pacific Energy FP30

Have you redone with blower off.

Also with IR gun shield the "laser" from bouncing with hand or paper. Make sure it's not getting a reading bouncing off.

 

[begreen]

Yes i had the blower running.

2018 Pacific Energy FP30

The blower will cool down the stove top. For a more accurate reading, measure with the blower off for 5-10 minutes.

 

[Tater1985]

Thanks again @MAD MARK and @begreen for the suggestion to check STT with the blower off. Yesterday afternoon I turned the blower off and let it warm up for about 10 minutes. Keep in mind that this was still heating up as I was waiting. With my magnetic thermometer straight above the door handle (top left)I was getting about the same 350ish readings from the stove top with IR gun as what the magnetic was reading. As it climbed to 400 the IR gun was showing closer to 425 on the STT. As it got up to 450 the IR gun was showing about 480 on the STT.

So I remembered that just the IR gun was showing higher temps above the middle of the door than it was on either side. So I moved my magnetic to top dead center over the door, now it jumped up to about 525 and the IR gun was giving me about 495 on the STT. So I worked it back towards the left in increments until the two temps were as close as I felt they were going to get. I would up with my magnetic thermos reading 500 and anything from 495-505 on the IR gun for STT.

For the load that was burning at the time, and MY stove, I wound up with the magnetic thermometer about 4-5 inches to the right of straight up from the handle (see pic). I will check this a few more times over the next week to see if there is any trend (hi or low from the IR STT reading) and make minor adjustment if necessary. This exercise gives me far greater confidence in trusting that magnetic thermometer.



2018 Pacific Energy FP30

 

[begreen]

Good deal. The blower cools down the stove top by quite a bit. 100-150ºF on our stove top.

 

[jatoxico]

My (admittedly old) Rutland is delayed in recording temp. Worse is I have seen it jump or flick to a new reading rather than climb or descend in a perfectly steady smooth way. Sometimes I'll give it a tap just to make sure it's not sticking. I figure I'm within 25-50 deg with it.

 

[saydinli]

Thanks again @MAD MARK and @begreen for the suggestion to check STT with the blower off. Yesterday afternoon I turned the blower off and let it warm up for about 10 minutes. Keep in mind that this was still heating up as I was waiting. With my magnetic thermometer straight above the door handle (top left)I was getting about the same 350ish readings from the stove top with IR gun as what the magnetic was reading. As it climbed to 400 the IR gun was showing closer to 425 on the STT. As it got up to 450 the IR gun was showing about 480 on the STT.

So I remembered that just the IR gun was showing higher temps above the middle of the door than it was on either side. So I moved my magnetic to top dead center over the door, now it jumped up to about 525 and the IR gun was giving me about 495 on the STT. So I worked it back towards the left in increments until the two temps were as close as I felt they were going to get. I would up with my magnetic thermos reading 500 and anything from 495-505 on the IR gun for STT.

For the load that was burning at the time, and MY stove, I wound up with the magnetic thermometer about 4-5 inches to the right of straight up from the handle (see pic). I will check this a few more times over the next week to see if there is any trend (hi or low from the IR STT reading) and make minor adjustment if necessary. This exercise gives me far greater confidence in trusting that magnetic thermometer.

View attachment 238297

2018 Pacific Energy FP30

Won't be long before you don't look at the thermometer anymore. You'll just know by how its burning

 

[Tater1985]

Won't be long before you don't look at the thermometer anymore. You'll just know by how its burning

I agree, but that probably wo t be until i feel like i have more control on the bottom end. I have been loading N-S the last few days and really like it. But when she climbs she does it quickly. That is even cutti g the air all the way back pretty early, well before secondaries. It happens because it starts from the bottom and is pretty well controlled until the secindaries kick in and then the top of the wood starts burning too.

2018 Pacific Energy FP30