Which thermo/hygro reading do I trust?

[Mike.P]

So I just got the Zoo Med Hygrotherm setup and running... I'll be getting a Herpstat 4 eventually, but for now I decided to use this. I have my UTH and Repti Fogger hooked up to it. I set the temp to 90, and let it get there. Then checked the glass right over the UTH with the tempgun, and it was only showing 83. After some experimentation, I set it to 100, and the tempgun is showing 92.5 in that spot.

Same deal with humidity... Set it to 55, but while the Hygro Therm was still only reading 45, my digital hygrometer was showing 63. After playing with that, now I have it set to 40, and the hygrometer is showing 55-57.

So who's right? lol

[mpkeelee]

I'm not familiar with the hygrotherm, but unplug the fogger and set it for the appropriate temp. Balls do not require high temp that a fogger emits so that is unnecessary. And plugging in two very different electrical items can throw off the output. With the hygrotherm controlling temps of belly heat until your herpstat arrives hopefully it will maintain appropriate temps.

[Mike.P]

Thank you! I think you may have misunderstood though... The fogger emits mist for humidity, not heat. The hygrotherm is made to control a heat source, and a humidity source. It's sensor measures both. It has two outlets, one for the UTH, one for the fogger, and controls each separately.

[mpkeelee]

Which is why I said I am not familiar with the hygrotherm. Either way. A fogger is not needed for ball pythons. All u really need is the hot spot to be where it is and a water dish. Acurites are so popular cuz u can place them inside to get a clear reading of hot spot and cool side with humidity. Keep the fogger unplugged and wait for ur herpstat. I only use the fogger for nebulization and sometimes bad sheds

[kitedemon]

I'll try to answer the original question. None. I would not trust any cheap thermometer and or hygrometer. The best least expensive thermometer I have encountered is the herpstat at 100$ for a +/-0.5ºF is actually quite a fair price. (unless you can deal with liquid crystal ones)

OK so lets move to realities. Few are willing to spend 100 + for a thermometer. Accurate hygrometers are so sensitive to dirt and dust that you wouldn't use one even if you have one. IR guns are about the same specs as all the rest +/-2º where in the 4 degree range is variable they also reflect off shiny objects so they must be used intelligently.

The best answer I have is buy a few of the same model and lay them out and compare them against each other. (5 is better than 3 but 3 will work) Typically two or three will read close to the same they are likely more accurate than the others. Almost all the sub 100 mark are the same specs +/-2º so by using a majority rules you can eliminate ones that are reading wrongly. I usually buy the cheapest (2-6$) I can and ten or more and mark the good ones and give away the bad ones.


Hygrometers are easily checked with a salt test (google salt test humidor) and choose one. It is easy and will get you to within 2% accuracy good enough. Personally I like ones that can be calibrated the little tags saying -16% and +32% bug me. I have a digital one but the calibration dial is easy to move and on the front. Sometimes my snakes take a turn calibrating it. I have abandoned it and gone with a cheap analogue calibratable model they hold accuracy for about 10 months or so. I check them every 6 because I am a spaz most would be ok with every 12.

Using a fogger is one solution to humidity, I have never done so my self but I see no reason why not. The only issue I have with it is it needs to be cleaned frequently (like every time you add water to it) ultrasonic ones are bad for bacteria so keeping on top of it is a good idea.