I took the advice from this forum and added another therm. I have one therm. that has a 2 1/2 inch stem at cooking level and added a therm. with a 12 inch stem at cooking level. I was shocked at the 2 readings. The 12 inch stem reads 75 degrees higher than the 21/2 inch therm. Both therm. are working properly. My fire basket is 11 inches in diameter, What therm should I go by? Should I make my basket bigger?