Are meat thermometer temperature probes standardized?

July 19, 2021 8:12 AM

I have a fancy Bluetooth meat thermometer, and I need some new temperature probes for it. It's been discontinued, though, and I can't buy new probes from the manufacturer. Will any probe with the right sized jack do?

All of the replacement probes for various brands look pretty generic; they all appear to be a probe attached to either a 2.5mm or a 3.5mm stereo jack (my thermometer uses 2.5mm.) Are these pretty much a standardized part, or are they actually all different from each other and just look the same? If I buy probes of another brand with the right size jack, can I expect them to work and give accurate readings?

posted by jordemort to Food & Drink (5 answers total)

Electrically, the probes will probably just be standard thermocouples.

Thermocouples come in several types, named by letters (e.g. Type J, Type K, etc). Each type has a particular response which depends on the metals used to construct it. The thermometer will only read the correct temperatures if it's used with the correct letter-type of thermocouple.

So you have two things you need to get right: the connector to fit your device, and the thermocouple type. But as long as you get those right, it should function fine - although there could also be food safety issues if the outer material of the probe is not appropriate for kitchen use.

I don't know enough about specific thermocouple types to advise beyond that.
posted by automatronic at 8:22 AM on July 19, 2021 [1 favorite]

Just from my experience, the probes I've seen with audio-jack connectors have been thermistor rather than thermocouple. The thermistor specs (resistance, temperature coefficient) need to match what's expected. No idea how much variation you find in consumer products.

If you have a thermocouple, it's very likely type K in cooking application. Normal connector is a two-prong.
posted by away for regrooving at 10:45 AM on July 19, 2021

Anecdotal of course, but I have a Taylor (from Target) with the long cord that you can put in the oven. The cord connected to the probe broke, and while I was waiting for Taylor to send me a new one, I got an Expert Grill Deluxe with the same long cord probe, and they are both interchangeable. I like the Taylor better because the beeper when it reaches the set temperature is louder.
posted by The_Vegetables at 11:37 AM on July 19, 2021 [1 favorite]

It’s possible they have something off the shelf, but more information is needed. Do you have the old thermocouples? Are they marked with anything? What’s the make of the thermometer unit? Do you have a spec sheet for the original unit? Will the company tell you what the specifications of the thermocouple are?

So, while there’s probably something off the shelf that might work, there also might not. For the sake of askme completeness the folks over at Omega will make custom thermocouples for you. They’re more geared towards industrial applications, but I’ve had some pro-sumer level products where I’ve needed very specific thermocouples built. They did a good, quick (read; not cheap) job. McMaster Carr also has a wide, quality selection…but again, more details are needed.
posted by furnace.heart at 12:56 PM on July 19, 2021

Response by poster: I saw something fancier than what I had on sale for $50 and snapped it up. It happened to come with probes with the same size jack. I plugged them into my old thermometer and it read them as 50 degrees over. So it seems that they are not standardized, even if they use the same connector. I think my chances are very low of getting thermocouple/thermoresistor specifications out of both (A) the company that no longer sells and is presumably disinterested in my thermometer and (B) another company that makes replacement parts for their own products and would rather just sell me one of their thermometers. I think that means my old one is headed for electronics recycling once its last pair of probes bites the dust.
posted by jordemort at 6:45 PM on July 19, 2021 [2 favorites]