Temperature Probe. Where to place it?

There should be multiple readers at various spots of your grow, the exhaust should be set to come on once RH% hits the threshold you set, the exhaust should be as high in the tent as you can get it, and the probe should stay at the top of the plant canopy, RH rises so by placing it at the highest point of the plant this will ensure Rh below this point is below the set threshold. Temp probe I like to have it sit on the top layer of leaves or close to also, the leaf surface temperature dictates the rate of photosynthesis, have a fresh air intake of colder air set to come in low on the tent.