Problem with Thermometer probes in high humidity?

Slannesh · 01-18-05, 06:58 AM

Hey all,

Just wondering if anyone else has had similar issues as i've had.

Recently I set up a cooler style incubator with water heated by a submersible fishtank heater. The heater is a good one (Tronic 200W) which is the same model I use on my 33gal fishtank and it works flawlessly. But recently i've noticed the temps that my digital termometer were showing were WAY out of whack.

It's the little oval white type with grey buttons that everyone seems to use Springfield Precise temp is the brandname. The probe comes covered in a little plastic nub with a bit of double sided foam holding it in. It was full of water so I removed the plastic bit leaving just the probe and about 3mm of exposed legs. I thought that would help and it seemed to for a while but this morning I checked the temps and it said it was at 110 degrees F. So, freaking out I grabbed my temp gun and checked the temps in each of the egg containers. 80-81 degrees just like they're supposed to be. So what i'm wondering is would the exposed legs of the probe be giving me whacked out readings because of the high humidity? The same thermometer seems to work perfectly fine in dry environments of all temps (I confirmed by using multiple thermometers and my temp gun to be sure)

If that's the case does anyone know a brand name of digtal thermometer that I could buy that keeps track of min/max temps that can handle the humidity in my incubator that I can get in Alberta?

Also, has anyone else had similar issues with that or any other brand of digi thermometer before? I'm now finding myself not entirely trusting about half of my thermometers all of a sudden.

Thanks!

BoidKeeper · 01-18-05, 09:50 AM

I had the same problem with some of mine too. I just can't remember the company name right now. I'm pretty sure they came from Wal-Mart though. I'll check when I get home. Like you I noticed that they just started getting way out of wack.
Cheers,
Trevor

Stockwell · 01-18-05, 11:57 AM

You can't have exposed legs... These units all use thermistors which are variable resistors. If water is present it across the sensor, it creates an additional circuit path(short) and you'll get incorrect readings.
I have never had a problem with the Radio Shack indoor outdoor type. You might try one of those.
The remote probes are water resistant but not necessarily waterproof for submersion.
If you were to put a covering of silicon seal all over it, that would surely keep all moisture out.. You might try that, but I've been using probe type sensors for decades in wet vermiculite and moss, and not once have I had a failure due to probe leakage.
Try another brand.

mykee · 01-18-05, 02:56 PM

I use the same ones in my incubators and I have them taped to the ceiling of the egg boxes so they hang in midair. Having used 4 last year, they all read perfectly for me. Mind you I never submerged any of them, but they all worked perfectly for months in 100% humidity.

Slannesh · 01-18-05, 05:31 PM

Ok that explains it then

I never submerged the probe but I did stick it in the moist Vermiculite to get an accurate substrate reading.

Do you think covering the legs with hot glue or silicone would fix that?

Jeff_Favelle · 01-18-05, 08:01 PM

I use the same indoor/outdoor ones from Springfield (Taylor) and I use them under water in my incubators. Never had a faulty one.

MouseKilla · 01-24-05, 02:55 AM

I have a $20 Radio Shack one too, works perfectly and the batteries never seem to die.

JDouglas · 01-27-05, 01:10 AM

I had three last yeat that crapped out on me just like yours. I had the probe in a sealed container with 100% humidity. They weren't even in water. They worked great at first but after time the humidity would get into it somehow and throw it off. I freaked out to because I was incubating carpet eggs. If I hadn't had a temp gun I would have gone crazy or worse yet turned down the incubator.

Slannesh · 01-27-05, 04:35 AM

had to be the water... I'm using the same one now to keep tabs on hot spot temps in my rack and it works fine.

Live and learn I guess. I think i'll use this incubator for this season but definitely invest in building a dry one with a thermostat and heattape like Uncle Roy's slick looking deal...

JDouglas · 02-05-05, 06:37 PM

You mean like this...

The thermometers I used that went wacky also work now that they have dried. I pulled the sticky foam off of one and put a thin layer of hot glue where the foam was. Now it is water proof and I have tested and it is still very accurate.

Slannesh · 02-05-05, 07:26 PM

Yup pretty much like that

Will · 02-13-05, 08:18 PM

Had that problem last year, and vented about it in this thread.
I still have a few Springfields in use, but for the most part I stick to the Raytek now...

Slannesh · 02-13-05, 10:46 PM

The only complaint I have about them is in high humidity environments... aside from that they seem to work ok... at least they're for the most part in agreement with my temp gun

If you read the fine print on them i'm sure it says they're accurate to within +/- 1 or 2 degrees which would account for the slight differences in temp that was mentioned in that other thread. Even my temp gun says it's accurate to within +/- 2 degrees F or 2%, whichever is greater. Bottom line, unless you're spending big money on lab quality equipment the best you can hope for is a close estimation on the temp or humidity.