Heat tape and thermostat question

So, I'm hoping to get a thermostat that comes with a 6 outlet strip, but, I'm baffled by it. How does it work to keep the temperatures correct when using 6 different outlets? If you have six shelves with heat tape on each shelf, all plugged in, what if the temperature is different on the bottom shelf as compared to the top shelf? I'm assuming that the thermostat only has one probe, so, umm, how do you make sure ALL of the shelves are at the correct temperature? If you get temp/humidity probes for each shelf, would you need to purchase a new thermostat if the temps are different for the different shelves or how would you correct this? Thanks in advance again!

on my rack i puth the stat probe in the middle of the heat source then i set the temps there at about 91-92 now the temps on the rows just above and just below will be around 89-90 and so on that is about all you can do

Awesome, thanks! I was worried about spending a few hundred for multiple thermostats.

yea, i did the smae thing...just hook the probe up in a descent location, and all of the strips of heat-tape will hit close to the target temps

The Ranco ETC-111000 allows you to hook up four temperature probes in combination series/parallel to do temperature averaging, but I have never done this with mine, and am not sure if it would give the desired effect. It's something to look into though.