In trying to determine the proper basking temp for my beardie I thought of an interesting question. Would a heat rock that holds a 110-115 temp be fine if there was a bright white light shining on it that doesn't give off any heat? ( I wouldn't do this, just hypothetical)
Should he basically be sitting on a 110 degree heat pad regardless of the temp shining on his back?
IF the temp of the basking rock needs to be 110-115, it would almost seem necessary for people to only use a temp gun for the basking area because of the many things that would affect a probe type thermometer. In my case, the light absorption due to the probe being black. My basking rock takes a lot of overhead heat to get it into the 110 range, somewhere around 120 degrees of heat from light. Same reason why wearing lighter colors keeps you cooler than black in the summer. In other cases where it is a stick type probe, the contrast of the heat coming from off the basking rock and the ambient temperature from being in direct sunlight would be contrasting, which is why thermometers come with instructions that say to not place in direct sunlight.
I realize this. Thats why it was hypothetical. Trying to determine exactly how basking temps work since different surfaces/materials require more or less heat to obtain that magic temp for babies. For my surface temp of his basking rock to reach 106, the temperature of the light shining on his back is around 120-125. Thats where the question came from. If you could buy a heat rock tuned into a specific heat (let's say 106 which for all intensive purposes would be the surface temp of the basking area as I understand it) and throw a bright white incandescent bulb over top that provides no heat, would it provide what everyone strives for in a basking spot?
One of the issues with heat rocks though is that they do nothing to raise the ambient temperature. Sure, the rock itself will be 115*F, but everything else in your viv will still be room temp. What ends up happening with heat rocks is that the reptiles end up clinging to them, since it is their only small spot of warmth, and since they are constantly on the heat rock it is easier for them to get burned when they short out.
That's why its better to use a basking light or a UTH on a thermostat to form a heat gradient... Your beardie/gecko/snake/ect will be much happier in a viv that is half warm and half cool, vs. a viv that is all cool with one very small hot spot.