Calibrating a TEMP probe with ice water

Jyetman · 11/14/2017, 07:55 PM

I have a apex classic and need to calibrate the PM2 temp probe. Can I use a cup of ice water thats partially frozen?

bertoni · 11/14/2017, 08:43 PM

That should be fine if you let the probe sit for long enough. I probably would do a bit of stirring now and then, too.

Jyetman · 11/14/2017, 09:07 PM

Quote:

Originally Posted by bertoni

That should be fine if you let the probe sit for long enough. I probably would do a bit of stirring now and then, too.

Its going to take forever at 15 minutes it dropped from 81 to 57 I gave up and trying a different way. I have a wired weather station and when I put its probe in the ice water it dropped from 81 to 32.4 in 5 minutes. I can assume its off by .4 correct? So when I put the weather station probe in my tank it reads 82 F so its really 81.6 F I think I calculate that right.

bertoni · 11/14/2017, 10:08 PM

That's probably close enough. The error might be a linear function or have some other form, but assuming a constant error of 0.4 degrees probably is going to work well enough. So the Apex probe was that slow in responding? Interesting. I don't know anything about temperature probes, though.

homer1475 · 11/15/2017, 03:54 AM

I think there may be something wrong with your probe. I calibrate mine using the same method(it's how we learned to calibrate cooking thermometers in school) and it reads almost instantly.

New apex or classic?

five.five-six · 11/15/2017, 04:12 AM

I just use one of these.

https://www.certifiedmtp.com/astm-17...hoCQeEQAvD_BwE

bertoni · 11/15/2017, 01:48 PM

I have a similar glass thermometer.

five.five-six · 11/15/2017, 10:44 PM

I wonder where you got it

11/14/2017, 07:55 PM	#1
Jyetman Registered Member Join Date: Nov 2012 Location: Phoenix, AZ Posts: 1,712	Calibrating a TEMP probe with ice water I have a apex classic and need to calibrate the PM2 temp probe. Can I use a cup of ice water thats partially frozen?

11/14/2017, 08:43 PM	#2
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	That should be fine if you let the probe sit for long enough. I probably would do a bit of stirring now and then, too. __________________ Jonathan Bertoni

11/14/2017, 10:08 PM	#4
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	That's probably close enough. The error might be a linear function or have some other form, but assuming a constant error of 0.4 degrees probably is going to work well enough. So the Apex probe was that slow in responding? Interesting. I don't know anything about temperature probes, though. __________________ Jonathan Bertoni

11/15/2017, 03:54 AM	#5
homer1475 Registered Member Join Date: Mar 2015 Location: Upstate NY Posts: 5,313	I think there may be something wrong with your probe. I calibrate mine using the same method(it's how we learned to calibrate cooking thermometers in school) and it reads almost instantly. New apex or classic? __________________ 80G SCA Build: http://reefcentral.com/forums/showthread.php?t=2560256 Originally posted by der_wille_zur_macht: "He's just taking his lunch to work"

11/15/2017, 04:12 AM	#6
five.five-six Registered Member Join Date: Mar 2007 Location: Corona Posts: 7,827 Blog Entries: 6	I just use one of these. https://www.certifiedmtp.com/astm-17...hoCQeEQAvD_BwE __________________ Originally posted by yellowslayer13: "I hate that hole" Current Tank Info: SCMAS Member 225 peninsula euroreef RS180 Apex 400W X 3 20k radiums / Spectra mixed SPS

11/15/2017, 01:48 PM	#7
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	I have a similar glass thermometer. __________________ Jonathan Bertoni

11/15/2017, 10:44 PM	#8
five.five-six Registered Member Join Date: Mar 2007 Location: Corona Posts: 7,827 Blog Entries: 6	I wonder where you got it __________________ Originally posted by yellowslayer13: "I hate that hole" Current Tank Info: SCMAS Member 225 peninsula euroreef RS180 Apex 400W X 3 20k radiums / Spectra mixed SPS