gradient w/ heat pad?

what are the air temps when using a UTH? what are the ground surface temps? is there a gradient of ground surface temps? also do all heat pads have to have air circulation under the tank?

Heat pads don't give you any ambient temps at all, and the floor temps all depend on the kind of heat pad.

Just shoot for temps of 90 on the warm side (no higher than 95) and 80-85 on the cool side. A night time drop is not required, but if it does just don't go below 75 (72 at the most). Measure the surface/ground temps above the UTH (where your snake would be) and make sure there is something between the tank bottom and the substrate - don't want your BP resting directly above the UTH for fear of burn. Attach a thermostat to your UTH to better monitor temps. Buy a digital thermometer with probes - not the stick on kinds.

The temps it gets to will depend on your room temp, kind of UTH, setting of the UTH, cage setup, etc. There's no way for someone to tell you what your temps will be. You just have to set it all up and see what you get. Just be sure to set it all up and get things correct and stable BEFORE adding your BP to avoid stress and illness.

I think that you are supposed to have some amount of air circulation under the UTH - don't want it to burn the stand (or whatever it's resting on).