Different temperature readings

[morpheon]

Hello everyone,

Here is my concern;

I have three different thermometers, and all of them give me different readings. Now, my question is: which one should i believe? Or, am i doing something wrong with any of them? Is there any way i could sort it out?

I joined a few pictures of the different thermometers, so you can give me some feedbacks.

The first device is a gun (you can point from far away), working with a battery. I bought it on the MegaRay website. I use it with the default mode, ie 95E, without using the min or max function.

The second device is something i bought on Ebay. It uses 3 AAA batteries and reads both temperature and humidity. It can be used with the sensor exposed and the sensor covered by its protector. On the second picture, the sensor is exposed, and on the third picture you can see it with the protector on in it's box.

The third device is something my parents-in-law borrowed me, because i wanted to find out which one is the right tool. Sadly, it wasn't that easy! It doesn't use any battery nor electricity and i have no idea how it can measure temperature and humidity.

Here is a picture from the top of my chameleon's enclosure. You can see in the top right corner some lamp. It's a 70w placed to create a located heat spot. This is where i took most of my readings. Don't be worried, i have a MegaRay placed in the middle of the enclosure, that i just moved to take this picture. So yes, it has heat AND UVBs. Don't forget that i live in the basement of a city north of Quebec, Canada. This means that i still have snow in my backyard and the temperatures are far different than where you live!

So, here are the results from my 3 devices:
1) Readings ranged from 80 to 95, from 2 feet away.

2) Readings WITH the protector were 74,5 to 74,6 and stable, while i waited about 20 seconds. Reading without the protector after 20 seconds was at at 75,5, while after 3 minutes it was at 80.0, and after 5 minutes at 82.1. After 10 minutes, it was up to 84,2 and even though it wasn't completely stable, i saw it going up and down by 0,1 a few times in 1 mins.

3) The third one, after a good 10 minutes, was up to 88-92.

As for the humidity levels, the number 2 and 3 devices are pretty much equal all the time, +-5 at worse.

What do you guys think? What do you suggest? Is there anything i did wrong? ()

 

[morpheon]

Here's the enclosure i talked about!

 

[sandrachameleon]

Temp gun is going to measure the temp of a surface. Digital and analogue metres will read the air temp. Both are useful.

Go to the store, buy three decent temp/humdiity guages. Put all three in the same place. Hopefully at least two of them will read the same as one of your other air temp metres. Return one or two of the new ones, keep one as a back-up.

 

[morpheon]

Will this ever stop?? I mean, i already have three thermometers and it's not fine already?

 

[xanthoman]

personally i would trust the digital one on the left, heres why; guns and other non-contact measuring devices are a marvel and useful tools but, bear in mind that most guns or other non-contact devices work by reflecting a u/v, ir, ultrasound or lazer, off of a solid surface, and air of course has no solid surface to reflect off of, so when you point a gun, you are not measuring the air temp, you are measuring the surface temp of what ever it is pointed at, not the ambient temperature of the air, which could be significantly different. of course no device is accurate unless it is properly calibrated and in good working order, but household quality (as opposed to lab quality) analog guages (with the physical dial) have a long term history for being notoriously inaccurate even when new, so especially if they are older and have been moved around a lot. digital stuff is less likely to go significantly out of calibration. so i would suspect that your gun works fine, for measuring the temp of what it is pointed at. that your digital guage is probably fairly accurate for measuring ambient air temp (assuming it has not been abused and has good batts), and that your dual analog guages on the right are probably more suited to a coat room than a chameleon cage. also its important to note that temps can be suprizingly different just inches away from each other, so it is important to use the exact same location when comparing temp devices. i am not that big on zilla products but zilla makes a pretty good digital thermometer hygrometer with dual probes on 56" leads for $20, it also has an alarm clock and hi-lo memory of both temp&humidity. http://www.zilla-rules.com/products/specialty-equipment/terrarium-hygrometer-thermometer.htm i think its a fairly safe assumption that if you buy a new digital thermometer/hygometer its reasonably well calibrated, but of course, like rpcv says the only way to test with100% certainty, would be to compare it against a certified lab/test quality therm jmo

 

[RPCV]

Do you have (or can you borrow) a mercury thermometer? An Hg thermometer is a primary standard that can be used to check accuracy/calibration of other devices.

If not then take Xantho's advice. The digital is most likely to be correct simply because the other is analog and the gun measures surface temps. not ambient air temps.

 

[sandrachameleon]

Will this ever stop?? I mean, i already have three thermometers and it's not fine already?

You have three completely different types though. If you want to verify the accuracy of one, you need something comparable. Like I said, the temp gun is measuring the surface temp. The others are measuring the air temp - but one is digital and the other analogue. I have at least two, usually three digitals in each cage - one near the basking area, one mid cage, and one lower cage. This way I know what is happening in every cage, at any given time. And they measure highs and lows over time, so I can check to see what the highest and lowest temp was while I was away ( at work or asleep, for example). I dont see this as overkill. Temp guages are CHEAP. Keeing the right environment - priceless.

 

[xanthoman]

she is right , you could not use even a certified mercury therm to test a noncontact device like a temp gun, one would still be measuring the air, the other would be measuring the surface temp. in order to test a non contact surface measuring device, you would have to use a similar device that was certified to a certain measuring standard. jmo

 

[xanthoman]

make it stop, an honest opinion

Will this ever stop?? I mean, i already have three thermometers and it's not fine already?

not to be rude but what would one expect.- if you get a fairly rare, highly specialized, ultra exotic animal its a pretty safe assumption that you that you are going to need at least some fairly specialized equipment. yes it will end (thermometer wise), when you go out and spend $20-40 per cage to get setup with 1-2 new, reptile oriented digital thermometer/ hygrometer(s). if you are going to spend $50-300 on a lizard and eventually $100s more on related stuff, then why would you try to avoid spending another $20-40 on one of the most important pieces of gear. if it was me , i wouldnt of even messed with it, i would have thrown all 3 in the garbage and gone out and bought a new reliable digital thermometer/ hygrometer for $20. i have 7 similar digital, therms (not all have hygrometer on them)
but all measure within one degree of each other when placed in the exact same location. even if you are already well setup, there will always be ongoing equip expenses, for example uvb needs to be changed every year (min) for those who bought t-12 lineal reptisuns in the last year, reptisuns have now gone to t-8 so to upgrade/update your bulbs, you need to also get new fixtures or at least do a ballast change (assuming they werent already using t-8), so you are right it never completely ends, thats just part of cham keeping. jmo

 

[morpheon]

Do you really think i didn't care with my temperature? I spent 100$ of both the temp gun and the other digital device. And if i wasn't cautious, i wouldn't have compared the two devices, don't you think so? And then gotten a third one. It's not like i used an old exo terra gauge that doesn't read anything either!

So far, you guys have suggested one new device. Is it the only one that everyone uses?

 

[fluxlizard]

This is why I watch the lizard instead of the thermometer.

He knows when he feels comfortable.

Thermometers just get you in the ballpark.

Nature doesn't do locations where it is 85.1 high 64.3 night every day of the year anyway.

 

[pantherlover]

nice post! i owned my first cham long before i got on this forum but ive learned so many helpful tricks since ive been on here. with my first cham i was dead set on getting the temps exact. what i did was more harm than good. id constantly have my hands in there, moving around branches, thermometers, the light up a couple inches/down a couple inches...its absolutely right that youve gotta get it in the ball park & let the cham do its thing. ive heard people keeping theyre panther chams basking spot, for example, anywhere from 85 up to 100. i personally dont let the temps get that high because i dont trust them to move if its getting too hot but i know of more experienced keepers who sware by it. my point is that 85 to 100 is a big difference & panthers for example have thrived for keepers who use temps on opposite end of the spectrum. so id say dont worry too much if your in the ballpark because the stress will be more damaging than a few degrees up or down. harry from chroma chameleons gave me some great advice when he said go for the lowest basking temp that produces the best stool. if its nice & pasty, your probably right on & even bring the temp down a bit to see if you can get the same result. if the poop is chunky & you can see bug parts, bump it up a bit untill you can see the chams food is well digested. once you got it close & the cham is looking & acting healthy, sit back & enjoy your pet. just do a check late in the day when the bulb has had time to heat up & make sure it hasnt gone outta whack. im not a pro, this is just what ive conjured up from more experienced cham owners over time. hope some of this helps.

justin

 

[jpm995]

Definately forget about the gun. The other 2 devices are getting similar readings. IF its calibrated right [their may be a test setup for this] the digital should be more accurate, but the mechnical one [i have the same one] is close enough and is more reliable [no batteries or circuit failures to worry about]. It will reacter slower to temp changes. Keep in mind your chams don't require 88.4 degree temps, they adapt to a wide range of temps. Close is good enough.

 

[morpheon]

I have ordered your suggestion Xantho.

Some of you may dislike the temp gun, but couldn't it be useful to measure my chameleon's temperature? If so, what should be the ideal temperature range? If not, why not?

 

[sandrachameleon]

I love my temp gun. I think they are very useful. The readings you'll get off the surface of your chameleon will vary, depends on whether it is basking or not etc. Worry more about having relatively constant air temps, with a gradiant from the top and bottom of the cage. Your digital is likely doing just fine, but it certainly doesnt hurt to have two digitals.

 

[xanthoman]

temp guns are use very useful as long as you remember they are for surface temp not air temp, and if you are pointing them at something like a basking branch you may also be getting readings from whats in back of the branch. if find them mostly useful for measuring things like bulb,/ heat emitter/dome temps etc. my cheap harbor freight one broke so i no longer use it anymore. yes they can be used to measure cham temps, but bear in mind that chams are cold blooded creatures, and do not have stable body temps like warm bloded creatures. a chams temp can vary widely, largely according to its enviroment, but also according to its, age, size, metabolism, etc. so it is difficult for anyone to say exactly what your chams temp should be at any given time, but i would say that its likely to be similar to its enviromental temps, maybe even slightly higher when basking, they are a great tool for making sure your cham isnt over heating while basking. i think if anyone were to give you specific temps, there would be at least a dozen posts claiming they should be different. after a month of using one you will have a better idea of what your cham temps would be than any of us could tell you. its important to remember that their temp is also affected by recent activity, so if you werent in the room with it prior to taking temps, it could have just left a basking spot or colder corner of the cage minutes before you walked in, so that could lead to misleading temps. i think if a chams temps were fairly predictable over a period of months and then suddenly seemed to be in a different range even though nothing had changed in its enviroment, then that might be a cause for concern, but i would not use body temp as a primary indicator of health. personally, if i were looking to spend money on more temp equip, i would just go out and get a another digital temp/hyg guage. many digital thermometer hygrometers remember the highest and lowest temps/humidity recently recorded, even while you are not there, so i find that more useful. jmo