I have a multimeter which has a thermocouple I can plug in to get a temperature reading. I really like the thing, but the thermocouple itself isn't all that robust. Although the meter is capable of reading temperatures up to 1850F, I doubt the thermocouple would last long at only 400-500F. My question is, is it possible to buy another thermocouple and use it in place of the provided one and still get fairly accurate temperature readings? I was thinking of maybe using a thermocouple normally used in furnaces or hot water heaters.

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tylervitale (author) 5 years ago
Thanks! I think mine is a K type because the J type has a limit of 1418 degrees fahrenheit because of the curie point of iron causing huge fluctuations in voltage. Because mine's limit is 1850F, it must be a K type...right?
Different thermocouples will create different voltages per degree, and it is likely that the meter is not designed to be adjustable, so it unlikely that you will be able to make a direct replacement. Perhaps a better solution would be to replace the insulation with something designed to take the heat.
tylervitale (author)  The Skinnerz5 years ago
I'm not as concerned about the insulation as I am the thermocouple itself. it's just a tiny bare wire junction. I'd feel much more comfortable having a much larger, thicker probe. (This will inevitably get a "that's what she said" comment)
I have a high temp probe that I purchased from Sears a few years ago (Craftsman brand name). It is meant for use with meters that accept the type K thermocouple. It has the same blade type connector and would plug right in. IThe spec sheet says that the insulation inside is good to a max temp of 1500 F.

The probe itself is like a metal spike a bout 0.2" in diameter and about 8 to 10 inches long, not including the handle. At the time it cost about $30 US.

I would suspect it is actually just a type K thermocouple inside a housing that can withstand the rated temp.

Its odds-on its designed for a type K thermocouple. Yes, you can buy new ones, from people like Omega