Hi Stbiven;
Welcome to the forum. Searching will provide you with a lot of information.
I'm assuming you had food in the smoker when you took these readings. The most common cause of such a wide variance of temperature is where your probes are placed. If you have the probes in-between racks or too close to the meat, those probes will read lower than the actual cabinet temperature. The next time you want to compare, place one of the Thermapros near the Bradley temp sensor, and see how those two compare with each other.