Just purchased a laser temp reader. How do i get the basking temp by pointing laser at the surface temp of the branch? . Branch is 6 in below top of screen and above that is a 8 in dome with a 60 w bulb cage is 2x2x4. I have a 4 m old panther. I also have a smaller dome with a 40w bulb next to that one.i am gettingreadings from 80 to 85 surface temp. Thaks