Cabinet Temp questions?

[TNRockyraccoon]

I've been told to place your cabinet temp probes just below the lowest rack you're cooking on. OK...Check.

Let's say I'm trying to cook at 225 on the bottom rack. So my temp probe registers 225 just below the lower rack.

What difference in temperature should I expect as we rise in the cabinet to the 2nd, 3rd and 4th rack position?

What if I'm cooking on the upper rack with the PID probe positioned just below the upper rack.....would my temps below the upper rack be higher or lower than the 225 my PID is set on?

With the PID, should I shoot for an average of 225 between the PID probe in the low position and maybe the maverick on an upper rack?

[GusRobin]

with the probe at the bottom rack, the temp on the upper racks will vary depending upon the size and shape of the meat. (Larger cuts may block some of the heat.). Eventually it will all even out.
Yes the upper racks will see lower temps but to me it is better than the lower rack seeing the higher temps if the probe is on the upper racks.