Heating question

I have been using a rack system with flex watt running up the back. I taped a outdoor thermometer probe to the back wall between the the tub and wall to read the temps. I kept the temps at around 93 (ball pythons are kept in the rack) figuring it would lose a few degrees from the wall to the tub. The snakes have done fine for 8 months with periodic refusing to eat which I assume was normal for ball pythons in december-february. I did notice that the bottom rack was getting cold and the ball python there wasn't eating and felt cool when I pick him up. I took a zoo med uth and wrapped it in tin foil and placed it at the front of the bottom tub.
Today i got my temp gun PE1 and when I took readings on the back wall at about 1 inch away it read 81 degrees which is a far cry from the 93 I was getting previously. I also read the outdoor probe that I had put on the bottom of the tub over the uth which read 91.8. When I used the temp gun it was reading 98 degrees. I then put the newspaper back and let it sit for awhile and took another reading and got 81 degrees. My question is what is the accurate reading and what is the best way to check reading on the tubs? Am I checking the temps right with the temp gun and are they reliable? I don't want to cook them and at this point they have seemed to do well with the outdoor temp probe but I also don't want to end up with RI problems and have been lucky they haven't had any or digestive problems up to this point. Any help on how to read the temps accurately and possibly how to warm up the bottom rack tub would be much appreciated.
Mark Westberg

Hey Mark,

First thing to keep in mind is that temp guns measure surface temps, the indoor/outdoor thermometers are reading the ambient temp around the probe itself. That is why you will get different readings.

My racks have about a 2 degree variance between the top tubs and the bottom ones. I have 5/10 slot racks that hold either 10- 6qt. sterilites or 5- 32qt. sterilites, or a combnation of both.

On the plastic wall of the tubs that are up against the flexwatt, (using a temp gun) I will get readings of 95 to 97 degrees. Yet the surface temps of the aspen substrate is 90 to 94 along the back of the tub and between 80 and 83 measuring the substrate in the front of the tub. When using my digital indoor/outdoor the temps usually read between 1 and 2 degrees cooler measuring the substrate temps along the back wall than the temp gun does along the back wall, but are usually with in one degree of the temp gun's measurements at the front of the tub.

So, you really need to concern yourself more with the temps inside your tub than the temps of the walls. Kinda like a light bulb, one the surface it is too hot to touch, yet an inch away the temps have cooled considerably.

So where should I aim when using the temp gun? Should I just point and click at the back of the cage or should I be a couple inches when taking the measurement? Thanks for your help.

The further away the temp gun is, the bigger the area it is measuring. The closer the temp gun is, the smaller the area it is measuring.

I personally take my measurements from about 2 inches above the area (substrate) I want to check. I also check about 2 or 3 areas in the warm part of my tubs/enclosures and 2 or 3 of the cool areas. That way I am getting a better idea of the temps all over the enclosure.

I have come to beleive that the acuwrongs are not worth a dime.. I have trashed several of them after about a week.. They say one thing and then the raytek will say something different... Just my thought...

the best way to use a temp gun in this type of application is to hold the button down, so that it gives you continuous feedback as you scan the target area.

there is a definite difference between air temps and surface temps, but using a temp gun and a digital thermo (they are complimentary to each other) you should be able to learn the differences and how they apply to your setup.

no use measuring the heat tape (or lightbulb) itself, but rather measure the area that the animal has access to, in this case, the substrate temps in the rear of the cage.

we use heat tape underneath our tubs, and it creates a hot spot that is perhaps 5 inches wide, hottest at the center of the strip. using the temp gun, start well before the heated zone, a couple of inches above the substrate, hold the button down, and slowly scan over the rear of the cage. you will see the temps rise as you get closer to the heat, and it will be easy to spot the hottest point.

holding the button down gives you constant feedback, and you can then see not only the hottest/coolest point, and adjust accordingly, but you can see how fast the temps taper off, how big the heated area is (big enough for whole body basking?) and how effectively the heat is penetrating through a few inches of substrate.

we have thermos connected to the heat tape, but they are typically set in the very high 90's. that is because the probe for the thermo may not be located right over the hottest point. so you take a mid 90's setting, let it come to speed, and then use your temp gun to see ACTUAL temps, and adjust the thermostat (or rheostat) accordingly. the setting of the thermo is RELATIVE to the cage temp, but not necessarily exact. another terrific aspect of having a temp gun : )

i hope this addresses some of your questions, if not, you are always welcome to call me directly by phone : )

Thank you so much for the explanation. The rack has heat tape running up the back. When I read the temps with the gun on the top slot it ranged from 87-93 across the back. The second slot ranged from 85-91. The therm with prob that is taped between the tub and back of rack is up at 100. I know that when I open the tubs I lose some of the heat but took the temps as fast as I could and as accurate as I could. This seems to indicate to me that I should keep the therm at the most 100 since I am dealing with ball pythons. I really do appreciate your feedback Robyn and am impressed with the concern you have shown for my questions. Very classy. I will probably be giving you a call just to verify that I am understanding everything correctly.
Mark Westberg