Measuring Liquid Solvent Temp in Pre-Chilling Column

Hello all,

I’m curious what solutions you guys who are chilling your hydrocarbons in a seperate jacketed column pre-injection with CO2 or other methods are using to measure the temperature of the liquid solvent inside the columns? I have 3/4" triclamp connections on my top column lids so I need something that can enter the column through one of those, but I’m daunted by the seemingly endless types of thermoprobes. I just need something that can measure from 0C to -80C and can be snaked in 5-10 inches into my column with a 3/4" triclamp connection.

Much appreciated as always,

Too bad they don’t make these things for lower temperatures. Or if they do, someone please tell me!

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Ask and you shall receive!

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Good find!!! Still doesn’t get us to -80 though


I couldnt find any colder than that.

I also only searched for 2-3 minutes, the term i used that found the best results was this

“liquid crystal thermometer”

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So I think I might have figured out part of it. It seems like there aren’t any 3/4" triclamp thermowells in the market, but I’m thinking if I get a 1" or 1.5" triclamp thermowell then slide a 1.5" to 3/4" cone reducer over the well, I could then clamp that to the 3/4" triclamp fitting on my column lid. Now i just need to figure out what probe to get to slide into the well as well as what reader i should pair it with. Also should have mentioned i have 4 columns I’d really like to read using one reader with 4 inputs. Any ideas guys?

How about a type T one of these?

Funny story while we’re at it: we were looking for a combo high pressure transducer RTD unit that would read accurate vessel temperature. We found two options, one was awesome but a bit pricy (about $800/unit). The other one was like $200 but they ended up coming in months late from the UK and had hella temp latency. While we were waiting, I reached out to TESCOM because they had an option that is basically this exact omega sensor with a 20ksi pressure rating; I figured in the interest of time we’d just throw two units in to get through prototyping. I was pretty blown away by the $16000 quote we got back. And lead time was, I shit you not, “whenever they need more for the F16s”.

Pretty quickly realized I was in the wrong room lol. I guess that’s probably a new level of “this sensor REALLY can’t fail or its a problem”.


how about this 3/4 try-clamp to 1/2" FNPT adapter.

and a 1/2" NPT to 1/8" compression fitting (good luck :wink: )
paired with any 1/8" sheathed thermocouple.

or skip most of those bits and just have someone weld a thermocouple pass-through directly to your column top

does require a different sheath diameter on your probe.

I’ve also made them in 1/8" by turning down these

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