I really have no idea. I wondered the same thing. That might make for an interesting discussion. It is a new thermometer from Lehman's. I actually measured the stack temp at the exit end of the first elbow. So that is pretty close to the back of the stove. I checked those temps again today and saw the same thing. If this link works it is a picture of my stove,pipe, and baro.http://nepacrossroads.com/download/file ... &mode=view
Ok ,I edited this and took temps again. This is what I got.
350 side (above the firebrick)
190 below the baro on the first elbow
115 above the baro as seen in the picture.
Only thing that might be different is I have added an aluminum shelf which I covered with aluminum foil. mounted it below the stove about 2" below the actual bottom that is where the ash pan sits. I noticed that on start up and no ash in the pan that the tiles were hotter than I liked below the stove. The tiles are not on cement board-only plywood. It keeps the tiles waaay cooler now. Maybe this reflects heat back into the stove and it has to radiate more contained heat off of the sides?
I'll snap a pic after and post it. It is nearly unnoticeable unless you are laying on the floor looking at it like when I am rolling around with my dogs.
Not doing anything innappropriate