Not All Thermometers Are Created Equal

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Consistent and accurate water temperature is important for the well-being of our livestock - whether it be fish, corals, inverts or bacteria. Do you really know what temperature your water is? Are you trusting your brand new temperature probe, or a cheap thermometer you picked up at the store? How do you know which is accurate?

NIST Traceability

NIST (The National Institute of Standards and Technology) is the overseeing body that maintains the U.S. standards for temperature.


Photo of NIST traceable thermometer by R2R member @ReefConcept.

How it works:

1. The thermometer manufacturer sends a thermometer (platinum) to NIST for calibration and it is then returned to the manufacturer.
2. The manufacturer calibrates a digital thermometer with their NIST calibrated platinum thermometer.
3. The digital thermometer is now NIST traceable and ready for sale/distribution.

Caveat: You have to trust your source as there is no official certification process the purchaser can use to verify the claims made by the seller.

NIST traceable thermometers are commonly used by laboratories and in the food industry. Although some of the fancy models cost several hundreds of dollars, you can find basic thermometers for around $50.


Now, here are a few questions you may be asking yourself:

Are controller probes or other thermometers commonly used in the hobby NIST traceable?

Generally, no. NIST traceable thermometers are a big deal, so any NIST traceable thermometer would clearly be marketed as such. The temperature probes I've seen offered in our industry have never been sold as NIST traceable either. Because temperature probes can (most of the time) be adjusted by a controller, it wouldn't make much sense for manufacturers to calibrate each one to a NIST traceable thermometer. However, it is smart to purchase a NIST traceable thermometer to do such calibration at home.

How would I know if mine is?

It would have been marketed/sold as such. Most NIST traceable thermometers are sold with paperwork stating what equipment was used for the calibration process.

Do NIST traceable thermometers need to be re-calibrated?

Absolutely. As with other devices we use - TDS meters, temperature probes, PH probes, etc, NIST traceable thermometers also need to be calibrated on a regular basis. I personally calibrate my equipment at least once a year.

How can I calibrate my NIST traceable thermometer?

It's easy, check out this video!

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About author
I have been involved in the saltwater industry since 1996. I have previously worked with importers of fish and coral directly, including obtaining some of the very first (and only) true "Lemon Drop" Bubble Tip anemones several years ago. I have been working with all types of anemones since I first started in the hobby, gaining one of the most extensive knowledge bases for a hobbyist in the process, and have run several very successful propagation systems.

In 2004 I got serious about water purification and began researching the topic, as there was a lot of misinformation out there (still is!) Im lucky enough to live by Spectrapure, the gods of water purification. I have also been involved in woodworking and plastic fabrication since 2004, in this industry.

My business Octo Aquatics™, has brought to life several firsts in our hobby - such as the clear screen aquarium lid (Octo Lid™), as well as other products that utilize high powered magnets cased inside my specialized Octo Pods™. My products are hand assembled right here in Arizona!

I am also an ex-professional photographer and have toured the U.S. and other countries with bands, and my work has been published world-wide.

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