Yeah, I found that one out the hard way. It was a little dark where the console was positioned, so I turned on the light and just left it on for convenience. I kept noticing after that, that it seemed too high. It was still new, so I suspected the calibration. I used my Fluke 87 to measure the temperature at the same location over a period of time and found it to be consistently 3? F lower on the Fluke. I then entered the bias into the console to match the Fluke and went on about my business. It wasn't long before circumstance had me turning off the light for some reason, and soon thereafter the temperature was showing 3? too low.
One might think that Davis could do a better job in the design, but in reality this is old school technology. If it was up to date with current technology, the console would be no bigger than its display, or even better, an iPhone.