I read a lot of you guys know that the areas of your pit are different temps, I am wanting to check the internal temp difference from top to bottom in my vertical smoker. What or how do you guys do it?
If you need to know the specific temp difference, then use a few thermometers. If you are just trying to find the hot or cool spots, use tube biscuits or bacon. Put biscuits or bacon at the different levels and front, middle and back and let them cook. When you look later you'll see some that are done more or less than the others.
I agree with Bludawg use those oven thermometers. One my new offset the temp is almost equal across the grates, end to end. My mounted Tru-tell sits 3 inches above grate height and reads 35-40 degrees higher that grate temp measured with oven thermometer and my maverick 733. The upper rack stays 50 degrees higher.
It is important to know what your cooking temps are and where possible hot spots are. But in the real world you get spikes and heat loss when adding wood, spritzing, basting, just about every time you open the pit.
The meat is done when it's done regardless of our estimated time and temp