Best Thermometer?

[Woodstock]

I am trying to calibrate my temp probes on my controllers but I do not know the 'true' temp of my tanks . I have 1 glass mercury thermometer and another mercury with a plastic 'frame' (made in Taiwan).... They read 3 deg difference!!!


What is the best accurate & affordable (not a lab grade $100+) thermometer?

 

[Charlie97L]

I calibrated mine with a medical thermometer, one of the electric ones that beeps... I borrowed it from my friend who is a resident, he calibrated it with some tool he had at the hospital... so that doesn't help you very much. I put it in one of those plastic sleeves while in the tank water. It takes MY temperature correctly, so why wouldn't it take the tank's?

As far as commercial... you might want to check like, anything used for medical purposes, doggie thermometers, etc. Anything electric there's always a chance of not being calibrated correctly... you should be able to check the calibration on a merc thermometer in a number of ways.

tape it on the wall next to your thermostat. if they read the same, your themometer is good. or let a bowl of water get to room temp... and check it against your thermostat again.

in our trade, i'd say any of those probe thermometers sold by the company that makes the PH/CA/ALK/NI probes will be right, but those are $$$.

 

[Woodstock]

I think I may try this one....

Premium Aquatics - Coralife Thermometer

Anyone ever use this type?

 

[Charlie97L]

nooooo

that's even labelled varying +/- 1.5 degrees. i have two, and they read 1.5 apart in the same water.

 

[Woodstock]

Thank you for the heads up

 

[Kensn]

If the thermometers go low enough, test them in a glass of icewater and see which one reads 32 degrees. You may be able to calibrate the controller like this also.

 

[K.G.]

icewater is not necessarily 32 degrees F, so if you're looking to calibrate better than a couple degrees thats not a good way to do it. i'd check it against a digital medical type thermometer, they're tolerance should be much more accurate.

 

[Woodstock]

Thanks guys~

*sigh* Does anyone have a digital medical type thermometer I could rent for 5 min?

 

[tikimon]

I'd go with the old fashioned glass therm. Or, you can always dip a finger and take a guess. Now that's the real old fashioned way.

 

[Woodstock]

If the thermometers go low enough, test them in a glass of icewater and see which one reads 32 degrees. You may be able to calibrate the controller like this also.

I think I will try the ICE method on my controllers tonight. I found a website that has the instructions. It is within +/- 0.1 F... that is close enough for me! Thanks Ken

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Ice Point Method ​

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►Fill an insulated cup with crushed ice and water.

►The cup must have enough crushed ice to provide an environment of 32°F, so you may need to pack more ice into the cup during the process.

► When the mixture of the water has stabilized in about four or five minutes, insert the thermometer to be calibrated to the appropriate immersion depth.

►Be sure to hold the stem of the instrument away from the bottom and sides of the container (preferably one inch) to avoid error.
► If your thermometer is not accurate within +/- 2°F of 32°F., adjust the thermometer accordingly. The ice point method permits calibration to within 0.1°F.
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[Charlie97L]

great information! i wonder if i can calibrate my stupid coralife therms?

 

[mps9506]

I've always used the ice method with my "meat" thermometers to make sure the roasts get hot enough.
by the way, just use the finger method to test the temp. And the taste to measure salinity

 

[Witfull]

I think I may try this one....

Premium Aquatics - Coralife Thermometer

Anyone ever use this type?

I have that one in my tank, and i also have a digital on my chiller. thay are appoximately within a degree of eachother. and i have a floating therm in my freshie tank. i put that in the reef and it was right there with the other 2.

by the way, just use the finger method to test the temp. And the taste to measure salinity

MIKE!!!! dont give away all the good tips,,,i was going to write a book "The Lazy Reefers Guide to Bending the Rules"~