I like to hve 2 or more probes. One for the meat and 1 for inside the smoker with an alarm. I also have the ones that are built in to the smoker/grill. The more the merrier and yes you should check all thermometers in boiling water if they go that high to see if they are correct. I have had 2 exact polders give off 2 different readings. Although only 8 degrees off it does make a difference.