Sciencemadness Discussion Board

Thermometer adapter interference

m1tanker78 - 17-11-2012 at 19:32

How do you all get around taking temperature readings when the desired temperature range is hidden by the thermometer adapter during distillation?? Forgive me if this is a dumb question. I have two mercury therms with different max temps but neither are visible in the ~35-40C range when properly placed in the still head (with adapter).

While I'm on the subject of therms.. The markings on one of my therms rubbed off. It seems that the markings are etched into the glass. Can I rub some very fine carbon powder into the etchings or is there a better or more permanent way to fix this?

Thanks,

Tank

Funkerman23 - 18-11-2012 at 00:04

I just rub some graphite into mine. Haven't found a permanent colorant but so far there has been no need. as for the interference it depends. the rubber boot adapters are what they are but I have gotten away with simply shifting the thermometer when taking a reading. I will say Laboy therm adapters tend to wipe off the ink on the thermometer but adapters vary so your experiences may be different than mine.

[Edited on 18-11-2012 by Funkerman23]

DJF90 - 18-11-2012 at 00:13

You may have better luck using a lower range thermometer. You don't specify what you have, but a -10 to 110*C range should allow the 40*C region to be visible. Generally you should use the thermometer best suited to the temperatures you're expecting. Another consideration is thermometer length, 150 and 300mm lengths tend to be the most commonly available, and you'll obviously have better luck with the latter.