Temperature Verification?

[myram]

What is the best way to verify the accuracy of a temperature probe?

How do you believe that a reading is accurate from one device to another?

I just took a probe from my Reef Angel and put it under my tongue, seeing that a normal person is around 98.6 degrees. The temp only got up to about 96 degrees and stopped climbing.
I took another probe and got the same results.

I have thermometers in the sump and display that read different from each other and from the RA.
I have an infrared temp gun that I can use as well to get readings.

But what do you really trust?

There are only a few things that are a "standard".........water boils at 212, water freezes at 32, and the human body is 98.6.

A difference of 2-3 degrees is huge in a reef tank, if you think you are at 78 but you are really at 75.........that could cause issues.

[Indymann99]

I would not worry if all are within a 2 deg range... I have been scuba diving for 30 yrs and the temps on reefs vary more than you think.

[Misled]

Originally Posted by myram

the human body is 98.6.

That's not always true. I run a little warm. Normally about 99.2.

On the tank water, just prevent any swings of 3 degrees or so. Change is more of a problem. As long as things are acclimated to temp they are in, they'll be fine.

[myram]

Well I know I'm not at 96 degrees............LOL

[disc1]

Body temp isn't a good standard. Boiling or ice water at equilibrium will get you closest. Though if you want to be down to the tenths of a degree you'll need to take things like barometric pressure into account. And you need to be using pure RODI. Anything dissolved in the water lowers the freezing point and raises the boiling point.

[myram]

Temperature is the hardest thing to verify. How do we know what we are using to test against is accurate too?

Guess I just need to put it in the back of my mind and not worry about it.

[disc1]

How accurately do you really need to know the temperature of your tank? What's really the worst that could happen if you're a degree or even two off? There are places in science where a tenth of a degree matters, but I don't think keeping a fish tank is one of them.

[tallball158]

As others have stated, I am personally more concerned with a temperature swing, than verifying the exact temperature. If you are within a degree or two on the calibration, I wouldn't sweat it.

[myram]

It just struck me that I have 4 thermometers in my system and none of them read the same.....even the ones that are right next to each other.

I know consistency is the key, but it's in the back of my mind.

[tallball158]

Lol yeah I guess if I had 4 different thermometers, it would bother me too!

[disc1]

How far apart are the readings on these 4 thermometers?

[myram]

I have a thermometer in my display and a probe from the reef angel in the display, right next to each other in the overflow.
I have a thermometer in my sump and a probe from the reef angel in the sump, right next to each other in the return part with the heaters.

They are all within 1-2 degrees of each other..........but never the same.

[outssider]

I got this to calibrate my jbj controller with temperature prob.

http://www.amazon.com/Hanna-Instrume...k+temp+1+hanna

I checked it against an oral medical thermometer and it read very close.(mercury)

[bnumair]

u can check the accuracy of temp prob by taking a cup of crushed ice, fill the cup with maximum ice you can then put just enough water to submerge ice in it. after 2 min read the temp. it should be 32F.

[phillrodrigo]

Originally Posted by bnumair

u can check the accuracy of temp prob by taking a cup of crushed ice, fill the cup with maximum ice you can then put just enough water to submerge ice in it. after 2 min read the temp. it should be 32F.

That's how we do it in the restaurant. It's how the Fda tells you to do it or even serve safe. If it's good enough to keep us from getting sick should be good for our fish

[bnumair]

Originally Posted by phillrodrigo

That's how we do it in the restaurant. It's how the Fda tells you to do it or even serve safe. If it's good enough to keep us from getting sick should be good for our fish

i am a serve safe certified,in fact i qualify for instructing the class (never did). Been doing this method for 20+ yrs

[Breadman03]

Originally Posted by Misled

That's not always true. I run a little warm. Normally about 99.2.



On the tank water, just prevent any swings of 3 degrees or so. Change is more of a problem. As long as things are acclimated to temp they are in, they'll be fine.

And I'm about 97.7-97.8. I feel like a doormat when I hit 99.8, but that wasn't high enough when I was in school. My wife sits about 99.

[disc1]

In the picture you posted I see 80.2 and 79.7. That's half a degree between two thermometers. Half of a degree. I don't know what you expect, but if half a degree variance doesn't satisfy you then your expectations aren't realistic. Either that or You need to spend a lot more money on your thermometers.

Try this, round both of those numbers off to the nearest degree. What happens then?

[myram]

Those are the 2 probes on the Reef Angel, I also have 2 thermometers mounted right next to those probes that are normally 1-2 degrees off.

[steamer51]

I have a certified lab grade glass mercury thermometer I periodically use to check the others. It tells me that one is consistently two degrees too high and the other is two degrees low. I don't think you can buy a cheap thermometer that is accurate but they seem to be consistently the same amount off over long periods of time.

[AcroporAddict]

I have an infrared digital thermometer I use for this purpose. It is the type mechanics use to locate hot spots on car engines. You can get them very reasonably at any local hoby shop that sells nitro RC Cars or planes, etc, about $28. Here is just one example of many available:

http://www.horizonhobby.com/products/DYN2529

But that being said, I have found that those cheapo $2.99 suction cup types to be quite accurate over the years. They always match up or are within within 1/2 degree or so with my IR Thermometer.