Sunday as I finished some Baby Backs where I was not using the meat probe I noticed the probe temperature was a lot lower than the smoker temperature. Today I did some tests. 1-- Initially, the smoker was setting outside in the TX sun. The Smoker Temp was 108 and the probe temp was 99. If ever the temperature should be equalized, it was then and I had a 9 degree difference. 2-- With the vent open and no water of meat in the smoker, I set the temperature to 225 and placed the probe on the lowest shelf. I took intermediate temperatures and the difference remained about 10 degrees. After 20 minutes the smoker temperature read 246 [overshoot] and the probe read 238. Still about the same spread. 3-- Now the smoker was hot, I placed the probe on the top shelf, [smoker still set to 225] . After 15 minutes, I checked the temperature. Smoker 245, probe 226. After 45 minutes smoker 239, probe 220. After 60 minutes, smoker was 224 and probe was 202. 4-- I then moved the probe to the center shelf. [Smoker still set on 225] After 1/2 an hour, smoker 224, probe 202. I then checked the temperature by inserting a 4 1/2" insta-read probe through the vent. Close to the vent it was 180, but full insertion with the vent closed as much as possible showed 200. Conclusion: The smoker temperature reads 10 degrees warmer than the lowest rack and the equalized whole smoker. [This is like an oven temperature setting being 10 degrees off the actual thus it is equipment related, The smoker reads 20 degrees warmer than the middle and top rack. [This is the position effect and includes the equipment error]The insta-read probe insertion confirms the meat probe general accuracy and the whole general premise. In the future I plan on taking the data into consideration when setting temperatures and relative meat positions. Has anyone else made similar observations?