How to calibrate thermometer probe?

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I just bought a high precision floating hydrometer and was amazed by the accuracy. Feels great to dial in my SG using a scientific-level device vs just trusting my refractometer.

For temp I'm using a reef-pi probe, laser gun and the digital readout on my heater. They're all different!!!

I've read about calibrating using ice water but I just don't have a great feeling about that.

Is there a thermometer you'd recommend for reference? Ideally something tall, granular and delicate. BRS has a calibration thermometer but it's expensive and appears digital. I'm hoping for something cheaper and basic glass. You know, the kind you drop once and go "gee wiz did I like that thing".

Cheers and happy reef-keeping.
 
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I had the similar problem and purchased the Hanna device from BRS that you mentioned.

www.bulkreefsupply.com

HI98509 Checktemp 1 Digital Thermometer

Knowing the temperature of your reef tank is very important, and with the Hanna Checktemp HI98509 Digital Thermometer, you can accurately know your aquariums temperature within 0.5°F. Each Checktemp comes with a 3.3' silicone cable that has a stainless steel probe at the end that gives rapid...
www.bulkreefsupply.com www.bulkreefsupply.com

It's $40 but gives me the peace of mind I was looking for.
 
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ReefBot Lab, Automated Water Tester
TexanCanuck said:
I had the similar problem and purchased the Hanna device from BRS that you mentioned.

www.bulkreefsupply.com

HI98509 Checktemp 1 Digital Thermometer

Knowing the temperature of your reef tank is very important, and with the Hanna Checktemp HI98509 Digital Thermometer, you can accurately know your aquariums temperature within 0.5°F. Each Checktemp comes with a 3.3' silicone cable that has a stainless steel probe at the end that gives rapid...
www.bulkreefsupply.com www.bulkreefsupply.com

It's $40 but gives me the peace of mind I was looking for.
Click to expand...
40 isn't terrible. Still leaning toward something analog/scientific but this just might be my option. Thanks for the recommendation.
 
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When you say "scientific", keep in mind this particular device is a lab-grade, NIST-certified device for calibration purposes. (in case that helps)
 
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Tidal Gardens
www.fishersci.com

H-B Instrument SP Scienceware Durac Plus ASTM-Like Total Immersion Laboratory Thermometers 117C | Buy Online | H-B Instrument™ | Fisher Scientific

H-B Instrument SP Scienceware Durac Plus ASTM-Like Total Immersion Laboratory Thermometers from H-B Instrument™. Safer than their mercury counterparts Shop H-B Instrument™ SP Scienceware™ Durac™ Plus™ ASTM-Like Total Immersion Laboratory Thermometers at Fishersci.com. Available in 117C
www.fishersci.com www.fishersci.com

My scientist buddy turned me on to this one. $700!!!
 
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Just reviving this thread b/c I was also wondering if there's some sort of consensus re: best "reference" / calibration thermometer? I'm getting meaningful (?) difference in temps from my Helios heater and my GHL temp probe but perhaps those differences are just due to placement? But I also had differences when I was using my inkbird and my cheapo Amazon heater as well. Given the interaction between temp and salinity, it seems like getting the right temp reading is pretty important.

Certainly appreciate that "chasing numbers" isn't as meaningful as stability, but just wondering if there's a generally accepted method for calibration.

Thanks in advance.
 
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Its a russian doll dilemma, buy another device and start thinking how to calibrate that other device. Not a bad strategy if you have loads of cash..
 
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Top Shelf Aquatics
Check out the Hanna HI98509 I posted earlier ... it's reasonably priced from BRS and super easy to use.

I use it once a month just to give me a "second opinion" that my Apex temp probe is still accurate.
 
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..or if you are a practical person mix ice with cold water, let it stay for an hour and check that your probe reading is 0 degrees celsius..
 
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AS
TexanCanuck said:
Check out the Hanna HI98509 I posted earlier ... it's reasonably priced from BRS and super easy to use.

I use it once a month just to give me a "second opinion" that my Apex temp probe is still accurate.
Click to expand...
Thanks. i have that in my cart and just wanted to see if there was anything else considered ”reference-worthy” before checking out.
 
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Tidal Gardens
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Just take 2 or 3 different thermometers and get the average. It's not going to be perfect but no need in stressing over something that isn't going to make a huge difference.
 
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www.dinkinsaquaticgardens.com
keithw283 said:
Just take 2 or 3 different thermometers and get the average. It's not going to be perfect but no need in stressing over something that isn't going to make a huge difference.
Click to expand...
agree that stressing isn't the point of this hobby - just trying to get as accurate as "reasonable". My current thought is to just try to ice method and see what it shows. At the very least, I'm now curious to try it out. Seems like an elegant, accurate, simple, and CHEAP way of finding out where things stand...
 
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JoeinLA said:
agree that stressing isn't the point of this hobby - just trying to get as accurate as "reasonable". My current thought is to just try to ice method and see what it shows. At the very least, I'm now curious to try it out. Seems like an elegant, accurate, simple, and CHEAP way of finding out where things stand...
Click to expand...
I have 2 jbj thermometers and a mercury one that all read within a degree of each other so I just took the average when calibrating my apex probe. I check the apex probe weekly just to see if anything has changed and it's still the average of those 3 within a few hundredths of a degree every time
 
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JoeinLA said:
dayum. yeah, i think the ice or mercury thermometer approach might be more in line with my financial capacity... :)
Click to expand...

Well, it's very difficult to buy a Hg thermometer these days. NIST won't even calibrate them anymore. Alternatives (alcohol?) are nearly as good these days.

I did read an article that said that after a few years a glass thermometer won't drift anymore so a 2nd and final calibration is all that's needed. It got my hopes up but apparently that article is controversial so...

I did spend $140 or so on a Traceable dual probe thermometer that came with a calibration certificate. After two weeks the probes were reading more than the specified margin of error apart. After a few months, one probe failed and was reading 99F in a bucket of newly prepared water. The 2nd probe still gives believable numbers but I still don't trust it that much.

The probes are thermistors so I might splurge (again) but for a thermometer with an RTD probe. And check it in an ice bath...

keithw283 said:
Just take 2 or 3 different thermometers and get the average. It's not going to be perfect but no need in stressing over something that isn't going to make a huge difference.
Click to expand...

I think a single point ice bath calibration would be better than taking the average.
 
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Top Shelf Aquatics
I also agree that as long as we're in the ballpark we should be good, but this question did get me thinking of how to do this cheaply. Doing an ice bath would be a good start but it would take at least two data points to calibrate the span/gain of the probe. So an ice bath reading for the 32℉ (offset) reading and then a second reading in boiling freshwater (212℉ at sea level, compensated for altitude as needed for the gain). Then repeat back and forth, adjusting when nessecary until the reading constantly repeat without adjusting.
But that lead me to another question. What is the safe temperature range for the device that is being calibrated?
For the Inkbird ITC-308, the website says "Temperature Control Range : -50~99 °C / -58~210 °F", not quite to 212℉.
For the Inkbird ITC-308-WIFI, the website says "Temperature measurement range:-40℃~100℃/-40℉~212℉", which has enough range to do this.
I could not find a safe range for the Neptune Apex Temperature Probe written anywhere. Does anyone know what it is?
(EDIT: "Your Question: What is the min/max temperature range of this probe?
Answer: 14 - 122° F". So this method should not be used on Apex probes,)
So I guess it could be possible to calibrate the Inkbird ITC-308-WIFI by this manner and then calibrate the Apex to the Inkbird.
Then again, after going back and reading this.....NAH, I'll just stick with my average readings! ;Hilarious ;)
 
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