Am I able to use smoker as designed?

[johnny42]

OK. I smoked 8 boneless, skinless chicken thighs tonight. I foiled the drip pan and the water pan and did not add water. I set the smoker to 225. I had a new untested thermometer in the smoker monitoring the temperature. I put the thighs in a bit before 7:00. I took them out just after 11:00. One of them was still under 165 degrees and I finished it off in the toaster oven. The MES said the temperature was 225 or so, but my untested thermometer read about 20-25 degrees cooler. The thighs stayed at 155 for well over an hour and a half. I put chips in the smoker twice. I kept cranking up the smoker a few degrees every now and then. Even though the smoker showed 225, the untested thermometer showed in the high 180's for the first few hours. My untested thermometer read 225 for maybe the last hour or so. The smoker read about 245.
If my smoker is going to show temperatures 20-25 higher than what they really are, I need to know that. I'll test my untested thermometer tomorrow in boiling water.
Couple questions:
Is there a better way to test my thermometer than just boiling water? I have a ThermPro TP17.
Is it worth adding chips after the first 2 hours?
Is there a best way to attach/mount my thermometer than just laying it on an unused rack? Should it be in the bottom, middle or top of the smoker? Left side, right side?
Finally, did it take over 4 hours because the temperature was so low for the first 2-3 hours? One chart I saw showed something like 1.5 hours!
I was in a hurry to get smoking so I didn't have time to test the thermometer.

Thanks for all the comments. I won't bug you guys after this..... but I might.....if I need to.

 

[chef jimmyj]

Boiling water gives a Known Standard that can easily be obtained. With the exception of Altitude variation water Always Boils at the same temp, 212°F at Sea level.
You want to know the smoker temp, at the meat. If the smoker racks are full, many measure at the middle rack for an average and swap top and bottom once or so.
Yes, the Chicken took 4 hours because the temp was low. We cook Chicken to 165, most prefer Thighs at 175-180. If your Smoker is at 180, even Thighs will take a lot of time to get there. Considering the Chicken Thighs, I've been seeing, are nearly 1 pound each, no wonder even after 4 hours one was not up to temp...JJ