you want to measure the air temp in the egg cups, not surface temp, and besides, when you open the egg cups to measure temps, you are letting a lot of heat out. I recommend you get one of the zoomed digital thermometers with external probe and put the probe in the egg cups. That way you can monitor the temps more accurately and without opening the incubator. I think the thermostat is probably more accurate than the temp gun for this application. Just a bit of a disclaimer, I haven’t bred bps so I’m not sure exactly what temps they need and all that, but I have successfully bred leopard geckos, and this is a problem I had myself when I was first calibrating my incubator. Good luck!