The
UTH temp depends on the substrate. YOu said it's on newspaper, so I wouldn't have the
UTH more than 90F. If there was an inch or so of mulch/aspen/etc than you can bump it higher.
Reptile Basics makes an outstanding temp gun for about $50. I've had mine for almost 2 years and it still has the batteries it came with and I've used it quite alot!
Nehushtan -
IMO the goal of a
UTH is to provide belly heat and minimal affect to ambient air temp. From my experience the pad has to be pretty hot (or the volume of the container very low, think shoebox) to have a great affect on the ambient air temp. Additionally the
UTH will
usually raise the temp in the cage about 5-10 degrees or so above the room temp.
But really it also depends on how you have the
UTH setup. If you have lots of open space under it, then you'll loose a lot of the heat. If you have a stack of cages and all the
UTHs are lined up on one side then it creates a better system and you have heat from teh top and bottom.