I was on a drilling rig today and used our company smoker and was going to cook for the crew. I picked up some briskets 3 of them from walmart. 2 of them were 15# and 1 10#. I was planning to smoke them for about 12 hrs at 210 to 230. That didnt happen. I set the temp at 220 with this smoker. I hadnt used this smoker before and trusted the gauge. I rubbed the brisket and put it in the chamber. I was there for about 3 hrs to make sure that the chamber temp would stay even. It did so I went to town to pick up plates and stuff i needed. I came back on the 5th hour of the smoke and decided to check the meat temp. It was at 195 I almost jumped out my shoes. I looked at the temp gauge and it said 220. Well to make a long story short. They were done in less than 6 hours. The meat was ok but had to pull. I checked the chamber with another thermometer and the camber at the grating was at 250 and the smoker gauge on top was at 210 Man I was ticked off. Bad guage i guess. If I would have come back after 8hrs that meat would have been burned. Close call today.