A Word on Humidity Gauges for my fellow Newbs

[Balboa]

It could be common knowledge not to trust humidity gauges and I just never caught on, but I never see it talked about in Care Sheets and the like, and considering how crucial Humidity can be to our torts I decided to post on the subject.

DON'T TRUST THAT $14 HYGROMETER/HUMDITY GAUGE FROM *INSERT BIG CORP PETS STORE HERE*

I'd guess most consumers are like me and expect that brand new gauge to be at least ballpark accurite when we open the package and stick it on the side of the enclosure. Well, not even ball park is good enough for torts, and it turns out you're probably lucky to even be in the ballpark. That's alot of faith to put in a very cheaply made item.

I knew the one that came to us with Rocky while only about 3 months old, was off. It was reading low, I just wasn't sure how much.

When I started setting up Rocky's new home, I bought a couple $2.50 real cheapies from HD for spot checking and an "expensive" $10 Digital one (notice thats cheaper than the $14 package from the big marts)

Here's what I saw when I laid them all out together



Not my idea of Ballpark. That darn Petco one probably explains Rocky's Shellrot when we got him. His Former Owner was probably drenching the enclosure to try and satisfy that thing. On the otherside, one of those cheapies that reads high could leave someone to believe they're doing great for their Tort, when in fact they're dehydrating.

I'm going to assume that the digital is the most accurate of the lot, but in reality I should pick up a couple different brands of those to compare.

Now I never really thought about it until I tried, but you can adjust these cheap mechanical gauges very easily. In the case of the Petco one the face pops off and the gauge will then fall out the front.



You can then carefully twist that lil brass L that holds the springy dealie until the pointer points where it should. They seem to stick a bit at first, takes some careful pressure to get them to pop without damaging the unit. I try not to touch the coil, not sure how much contamination or bending may impair it. The cheapies didn't even have a back on them, the coil is right out there to get wet, damaged, whatever, have to be careful with those when sticking them around the enclosure.



All fixed up.

Now, I don't know, but I suspect these mechanical units also have some range accuracy issues, and will be only really accurate around the point they're calibrated to, so might be a good idea to sync units at your desired humidity. As far as a perfect way to truly calibrate these things I have no idea. Dunk them in water for %100? I dunno.

Hope this helps some of you.

 

[PeanutbuttER]

Great post!

My favorite cheapo gauge is one that I've seen is one that petco and petsmart usually sell. It just says "desert", "moderate", and "tropical" but gives no numbers to go along with it. Junk.

I seem to remember reading elsewhere on the internet that you can calibrate hygrometers by placing them in a sealed plastic bag with a drenched paper towel (possibly with a salt solution, I don't remember) to simulate 100% humidity. I didn't know how to actually calibrate/adjust it though so that was a very helpful picture. Makes me even more suspicous of my hygrometer...

 

[TicoTheTort]

I just picked these up from my local Wal-Mart. There were only around $6 and seem to be working pretty well. I have put them under different heat/humidity tests and they both seem to put out the same numbers. The pictures are after they have been sitting in my kitchen for around 48 hours.

For the money I would say these are a pretty good buy.

 

[Tom]

Great post Balboa. Here's the one I like the best. Bought it at Lowes for around $25. It has a remote probe that you can put any where, indoors or out. I have about ten of these and they are are pretty accurate. I've had lots of them over the years and these are the best I've found.

http://tortoiseforum.org/Thread-Wireless-Remote-Thermometer

For some reason none of them read any lower that 16%, but they all go up to 99%. I have one that the humidity is all of kilter, but that's because my Tegu, Cleo, picked it up and chucked it in her water bowl. I guess since she couldn't swallow it whole, she thought she'd put it in the water bowl to soften it up. I can all ways tell this remote probe from the nine others because of the teeth marks. Haha.

 

[Balboa]

My favorite cheapo gauge is one that I've seen is one that petco and petsmart usually sell. It just says "desert", "moderate", and "tropical" but gives no numbers to go along with it. Junk.

LMAO you know what, I like that, as that's as accurate as it is, at least there are no incorrect numbers to mislead you LOL
Nice Idea with the paper towel in a bag, perfect.

Good Find Tico!

I've Eyeballed those many times Tom, now that you've endorsed them I'll be picking some up soon. I really don't trust Rocky around those squiggly little probes, looks like worms, yummy.

 

[PeanutbuttER]

Tico, those look pretty consistant. I wonder how accurate they are though. I'm a student and I am almost 100 percent certain that somewhere on campus I'd be able to get access to a research quality hygrometer (we have tons of random science stuff scattered across campus if you know where to look). I may just have to buy one of those next time I'm at Walmart and check it against something accurate. Great find if they are!

 

[GBtortoises]

I have a variety of digital and mechanical thermometers and hygrometers in use in my tortoise room and other areas of my house. In general I've found that "store brand" digital thermometers are not very accurate but the digital hygrometers seem to be. Most store brand liquid filled thermometers seem to be pretty good as long as they are calibrated with a known accurate thermometer. You have to be careful with the store brand liquid filled thermometers because they are not always correctly mounted in their housing. Any mechanical hygrometer that I have used has been inaccurate junk. For my incubators I use only lab quality liquid filled thermometers and usually place a couple of digital hygrometers within the incubators in order to have an average to work with. For my tortoise room I am not concerned about maintaining a precise temperature or humidity level as long as I know they are within the range that is required.

 

[Balboa]

A Little update and caveat;

My cheap little Digital has already died, presumedly from excessive temps and humidity beyond its design tolerance LOL

That would be the plus to the mechanical ones, no little ICs to fry. Just gotta check the calibration once in a while

From Tom's good luck with the remote units, they might be a little sturdier, I need to spring for some.

 

[Mao Senpai]

I went to lowes and they had the ones Tom was talking about and I ended up buying 3 at 18 dollars each. One for each enclosure and... one for my room since I liked the simplicity and I wanted to know the outside temps as well
All three were accurate and works great so far. They... do use quiet a few batteries (5 each) but should last a long time.

 

[ticothetort2]

PB, you will have to let me know if you do test them at school. It will be interesting to see how they stand up to research quality equipment. While they haven't been in a tort table (yet, I have recently put a deposit down on one of Tom/Cory's Gpp's!!) they have continued to put out similar numbers throughout my house as well as outside. I guess the true test will be once they are subjected to constant heat and misting. We shall see...

 

[froghaven5]

I just picked these up from my local Wal-Mart. There were only around $6 and seem to be working pretty well. I have put them under different heat/humidity tests and they both seem to put out the same numbers. The pictures are after they have been sitting in my kitchen for around 48 hours.

For the money I would say these are a pretty good buy.

I've used these ones from Walmart when we were incubating chicken/duck/guinea eggs. I thought they were good until most of our eggs didn't hatch. Calibrated 2 different ones using instructions on this site http://exoticpets.about.com/od/herpresources/ss/hygrometer.htm
and found they were both really off by alot.

 

[Balboa]

Aha, so that's how its done. After bothering to search the subject I found this page, which I like better, actually explains the science a little bit.

http://www.cigarextras.com/calibratingahygrometer.aspx

they also warn not to do this with electronic models ... ruh roh

actually I don't see why not, as long as you don't get any salt on it, but in the little electronic one I have, there's no where to calibrate it (it came apart for investiggeratin' today)

 

[PeanutbuttER]

TicotheTort-

I went to Walmart and they didn't have them! I ended up buying what looked like a similar one, which looking at it now is almost the exact one that Balboa got that has already broken X(

I'll still look into whether or not I can find some lab quality hygrometers and thermometers on campus to use to verify humidity and temps on it.

 

[ticothetort2]

FrogHaven-
Thanks for the heads up, I will have to try this method for cal out and see how mine do. I will keep you all posted on the results.

PB-
Yeah, the must sell out fast. I went back and they were sold out at mine. Good luck in the quest around school.

 

[Balboa]

Hehe, Don't freak out too bad Peanut, not too surprisingly after a couple day dry out the electronic one is working again. Luckily nothing seems to have actually fried (which is still a possible occurance) from whatever moisture short I had happen.

It just tells me that a properly calibrated (and Ideally better than $2 quality, if available) mechanical MAY be a better choice for REALLY humid applications. Airflow plays a part here as well, the intentionally tiny little vents on these things don't help much to prevent condensation in the device.