What form of thermometer do you prefer to use for adjusting heating temps. I"m getting different reading from different types of thermometers and was looking for some input on which to trust. I have two Zila thermostats inside the viv (one on cold side, one on hot side). When I use the ambient reading on my ir gun (Zoo Med rt-1) I'm getting different readings compared to the digital thermostats as much as 15 degrees on the warm side. Which really doesn't make any sense because the higher reading is coming from the digital thermometer and the lead is in the shade on the warm side.