Are these temp readings possible?

[kc261]

My Acu-rite is giving me temp readings that are up to 20 degrees different for 2 places that are about 20 inches apart, and with mostly open air between them. Neither the probe nor the main device is under a hide, or behind anything else that might make it a sheltered spot where I might expect such a significantly different temperature.

My tank is a 20 gallon glass tank with a screen top. A piece of styrofoam like stuff is setting on the screen and covers most of it to insulate and trap the humidity. We are using a UTH for heat. It is connected to a rheostat to enable us to fine tune the temps. We have the $12 digital Acu-rite that gives temp, humidity, and another temp from the probe. When I checked the gauge a few minutes ago, it read 90.9 warm side, and only 70.9 on the cool side! Humidity is 44%.

I know 70.9 is too cold. That isn't my question. I'm wondering if I need to figure out a way to add a little heat to the cold side preferably without totally changing my set-up and buying more stuff, or is it more likely that I have a faulty Acu-rite?

We did notice when we first installed the battery that even when we put the probe right beside the main unit, the probe consistently read about 2 degrees cooler than the main unit. We weren't terribly worried about it since I have heard that the digital gauges are accurate within 2 degrees. But now that we are getting such a big difference within the open area of a fairly small enclosure, I'm wondering if the whole thing is messed up.

Any thoughts?

[Argentra]

It's entirely possible. My 20gal is well set up with the screen foil insulated and the temps were great during summer. Now that its cooling down, my warm side still stays between 88(at night) and 92 with the t-stat, but my cool side dropped to 74 at one point.

My suggestion: get a second UTH for the cool side, especially if you live somewhere that can get really cold, like me, on a t-stat preferably. I found that rheostats are fine for the warm end, but they can't get down far enough for the cool side even on the lowest of the low settings. The second UTH, well controlled, should keep your temps stable throughout the winter...and if you add foam insulation to the three sides of the glass (as I'm about to do), you should be good to go.

[Krazy99CL]

Pictures are a little bit better to assist you and answering your question. Im thinking you have the accurite to close to the vent opening....

Right now all we could do is assume this and that.

[kc261]

Thanks for the replies. Unfortunately, I don't have a way to put up any pics right now.

For the moment I'll go with the assumption the readings are accurate. I need to figure out a way to verify it without buying another thermometer.

The open part of the screen top IS on the cool side of the tank. I was thinking if I put it on the warm side, the heat would just go straight up & out. Should I reverse it? Maybe less heat would get to the cool side, but once it got there it would be trapped making it stabilize at a warmer temp?

I already expected to need to get a t-stat by the time winter gets here. It does get cold here, but not as cold as Denver! I just thought I was done with the spending for right now. Oh well. I guess I'll be heading out later to get a t-stat and another UTH. I assume a smaller size UTH is ok for the cool side? Or does it need to be even coverage, just kept cooler by the t-stat?

I do already have a very thin make-shift insulation on 3 sides of the tank. My plan is to get that foam poster board stuff and decorate it to make an attractive backdrop for the more permanent solution. I hoped with the mostly mild fall weather getting it done in a week or 2 would be soon enough, but maybe I should get some thicker cardboard so the temporary insulation will be more effective. Maybe I should also get something that could be put on the front of the tank at night to minimize night time drops in temp?

In the very short run, I've got a lamp I can turn on and aim where ever necessary for a few minutes at a time to raise the temp. It makes the temp jump up pretty fast, so I don't even step away, just watch the gauge. But once I've done this it drops off a lot slower.

Thanks again! I welcome any more suggestions or comments.

[JLC]

To verify without buying a new thermometer (although it never hurts to have a spare)....try switching sides with it. Put the unit on the warm side and the probe on the cool side...and see what kinds of readings you get.


If the room you have the tank in is around 70 degrees, then it IS likely to actually be that cool in there. UTH's are great for creating a basking spot, but they won't warm the entire enclosure...especially if it's a big, glass tank.

Try getting another dimmer switch for the lamp so you can leave it on all the time as well. (But you'll need to get a red or blue bulb so it doesn't bother the snake...or a ceramic heat emitter...which screws in like a bulb but doesn't put out any light, just heat.) Sounds like you definitely need some supplemental heat to get the overall ambient temps of the tank up closer to 80.

EDIT: One more thought about a second UTH for the "cool" side....I wouldn't. Again, it will just create a small warm spot, without actually adding any additional heat to the tank. You need something to radiate warmth and warm the whole tank up to around 80.

[icygirl]

I wouldn't assume it's accurate. I JUST bought an Acu-rite thermometer/humidity gauge yesterday (digital one with probe), and it was reading normal temps this morning... I come home and it says the temperature is 43.9F on warm side, 39.7F on the cool side. I think I would know if it was that cold in the room! Talk about Acu-wrong.

[jotay]

I wouldn't assume it's accurate. I JUST bought an Acu-rite thermometer/humidity gauge yesterday (digital one with probe), and it was reading normal temps this morning... I come home and it says the temperature is 43.9F on warm side, 39.7F on the cool side. I think I would know if it was that cold in the room! Talk about Acu-wrong.

Just a thought did it some how get switched over to celseus ( sp ) ?

[icygirl]

Just a thought did it some how get switched over to celseus ( sp ) ?

Nope, it's still Fahrenheit.

[hoo-t]

I don't currently have an Acurite brand thermometer, mine's Radio Shack. But, you should be able to tell where the main unit gets its reading from by looking at it. Mine has a little "speaker grill" looking opening on the front. I can place the probe on that grill to get the inside and outside temps reading the same. You should be able to accomplish the same thing. If not, you could probably stick the whole thing in an ice chest (no ice!) or other insulated container, wait a while, and the inside and outside temps should be pretty close.

Steve

[Stewart_Reptiles]

The temp difference is possible.


To maintain temps between 80 and 84 on the cool side you have several options

1# Buy an additional heat mat as well as an additional thermostat set to achieve 80-84 or
2# Have your BP in a room where the ambient temp is maintained in the low 80's with the help of a oil filled heater.