Here's how I'd do this. Take one thermo, usin tongs hold the probe in a pan a boilin water so that it touch's nothin but water, take yer readin. Should be in the neighborhood a 212 degree's give er take accordin ta yer altitude.
Now, take that same thermo out ta yer rig, place the probe some where bought in the middle of yer box. Put water in yer pan an have the chip box over yer burner (Ya don't need chips er chunks in it). Now, start a smoke just like ya always do. That probe is gonna give ya the air temp in the middle a yer box. That's whats doin the cookin. Now in an empty box, it shouldn't take real long ta get ta temp. I'd use 250 degree's just cause it is where most a the smokin is done.
Now, ifin yer not gettin ta temp in an empty box fairly quick, yall got the burner down to low, er there be a problem someplace with the heatin side a thins. I can crank up the burner on the GOSM an be ta temp in bout 15 minutes. Then adjust the knob ta hold between 225 an 250.
Got ta thinkin bout this some, we are interested in the air temp here, gettin it ta 250, our food never reach's that temp, more in the 170 - 200 degree range. So at this point leave the food out of the equasion, just worry bout air temp. When yer satisfied with that, make up a fatty an smoke it. I generally take them ta bout 162 degree's, so have a second tested probe fer the fatty, It should take from 2 ta 3 hours ta get a 2 plus pound fatty ta 162 in a 250 smoker. That time is just an estimate based on the records of the fatties I've done.
Hope it heps.
