Sciencemadness Discussion Board

K2 thermocouple and distillations

NEMO-Chemistry - 30-11-2017 at 20:02

Well i splashed out on thermocouple :D, is supposed to be in the UK but has a W000 tracking number, so me thinks its a china one.

looks like a 4 channel nurdrage type thingy. I decided to get it because i broke my 320C mercury thermometer!!

Thing is i have no idea how to house the sensor bit for things like distillations!! I have thermometer squash whats its for my flasks, so can i buy some glass tubes, fuse one end and insert the sensor in the that? Then just put the glass tube in the thermometer pocket thing (bloody name escapes me).

is it ok to use soda glass tubes? I am a bit anal about having my thermometer bulb bang on inline with the adapter take off for the condenser, or i would use a pre made pocket and just put the thermocouple in that.

How do people use these theromo's in flasks etc normally? I dont fancy just risking heat shrink and silicon sealer :D.

I am aware they have a +/- 1C accuracy, but i have another mercury thermometer for when i need more accuracy. I just dont want to risk loosing my last one on normla stuff i do.

XeonTheMGPony - 1-12-2017 at 03:27

you can fuse the sensor right in to the glass, use borosilicate, as waste to go to all that work to end up with some thing that will crack all the time.

Ubya - 1-12-2017 at 03:51

i also use this kind of thermocouple (yep because i broke my only mercury thermometer hahahah) you could use a pasteur pipette, melt the tip and use it in the thermometer adapter, simply put the thermocouple inside with some kind of conductive fluid (mineral oil, thermal paste, mercury, you decide). if you don't want to make this "adapter" by yourself you could buy one, i think they are called thermometer well adapter.

ddc599b586ae0abe4100849de634a3d9.jpg - 12kB

[Edited on 1-12-2017 by Ubya]

Magpie - 1-12-2017 at 10:54

I use a 12" x 1/8" ss304 TC by Omega Engineering. I use them like a regular thermometer, immersing them directly in the reaction mix, when possible.

happyfooddance - 1-12-2017 at 11:48

Pretty much what Xeon said, but: Take a 7mm O.D. boro capillary tube (or make one), shove the thermocouple as far down as it will go, and melt the tip closed. Use it in any standard thermometer adapter.

I have seen Pyrex capillary tubes for as much as $25 usd for sale, you can make your own. I bought a ten-pack made by Kimball glass from a seller on ebay for about $20 plus shipping.

NEMO-Chemistry - 1-12-2017 at 11:55

Thx, i will post a pic of it, its a cheapy but for normal things it seems ok. I didnt realize the actual metal sensor part is tiny. Apparently it handle from -200 - 2000C. Thinking about it, i could just seal one end of a borro glass tube the same diameter as a thermometer, then use a normal thermometer thing...

I am on new anti convulsents, it has played havoc with my short term memory. my spelling is bad at the best of times, but at the moment.....

Still i am told it settle downs after a month or two. on the plus side i do fell alot better with the new drugs.