Temperature Variation

Just ran an experiment with my new Inkbird 6 probe wireless thermometer. Put each probe on a different shelf of my Oklahoma Joe Bandera and then dropped a full chimney of lit charcoal in the fire box. Wanting to see how much difference there was in the temperature in the cooking chamber, top to bottom. Interesting results. As the temperature was rising the top level (about 2 inches from the top exhaust) was running 30 to 40 degrees above the bottom probe, which was sitting just above the empty water pan (left it in empty as a heat diffuser). Didn't expect that much difference in such a small confined area. As the temps began to level out the differences also narrowed, but the top was always at least 20 degrees hotter than the bottom. And the change was not as evenly distributed as I would have expected. The bottom three probes were usually 5 to 10 degrees apart, top to bottom. Meanwhile the top two were substantially higher, usually 15 or more degrees above the hottest of the bottom three. Also discovered that the thermometer in the door was pretty accurate, usually within 5 to 8 degrees of the digital thermometer at the same level. If this experiment is "normal" I can assume that the temps above the included thermometer will run 10 to 15 degrees above it, while the area below the in door thermometer will run 8 to 10 degrees below.*

Also one of the 6 channels on the unit malfunctioned. It read 210 degrees on the back porch! The other 5 read 47 to 50 degrees! I am returning it to Amazon for a refund and will either purchase another one (maybe just got a bad unit?) or perhaps their 4 probe, rechargeable, unit. Since channel 2 did not work there was a larger distance between 1 and 3 than between any of the other operational probes. That accounted for some of the large difference between the top 2 probes and the bottom 3. But the difference was still larger than I would have expected.*

While I always cook to a specific internal meat temperature, knowing this about my cooker will help me plan how much and how often to add fuel and how to plan a cook better. Still love the Bandera.

Answers

I have a 40" extension on the little smoke stack that came on the bandera. I have a discussion of the mods I made to it elsewhere in this forum.

https://www.bbq-brethren.com/forum/showthread.php?t=257001

Also I did test three of the probes in the number 2 channel port and all read the same 210 degree error.

The batteries were brand new Duracell

Plan to run the test again tomorrow or Monday with the water pan filled to see how if that makes any difference in the degree of variation (I know it will affect the overall temperatures).

OK here are the results of the new test of Temperature Variations of Bandera with Full Water Pan. My wife noted that the temps "settled down" after about the first hour and that she had noticed that on all the shows of "Man, Fire, Food" as well as Aaron Franklin's videos that they built their fire and THEN went and prepped the meat, giving the cooker time to warm up and settle in. Probe 1 and 2 were above the thermometer in the door and probes 3 and 4 were below it (thus the order). Not sure why the web interpreted the spaces in the spreadsheet as asterix(sp).

Time* * * * *Probe 1* *Probe 2* * Door* * Probe 3* * * Probe 4
3:45 PM* * *109* * * * *108* * * * * * * * * * *102* * * * * *181
3:56 PM* * *117* * * * *107* * * * * * * * * * *106* * * * * *205
4:00 PM* * *178* * * * *171* * * * *150* * * *163* * * * * *286
4;15 PM* * *237* * * * *214* * * * *190* * * *311* * * * * *316
4:30 PM* * *241* * * * *223* * * * *200* * * *313* * * * * *302 Added a hickory log
4:55 PM* * *239* * * * *239* * * * *218* * * *237* * * * * *235 Added charcoal
5:15 PM* * *270* * * * *266* * * * *262* * * *255* * * * * *253
5:30 PM* * *264* * * * *270* * * * *262* * * *255* * * * * *253
5:45 PM* * *255* * * * *261* * * * *240* * * *250* * * * * *250
6:00 PM* * *198* * * * *199* * * * *198* * * *199* * * * * *203
6:15 PM* * *180* * * * *181* * * * *180* * * *183* * * * * *183
6:30 AM* * *163* * * * *163* * * * * * * * * * *165* * * * * *167 Stirred the charcoal
6:55 PM* * *167* * * * *171* * * * * * * * * * *172* * * * * * 167