I have a liquid-in-glass thermometer that will record the min/max temp that it experiences (a six's thermometer). But it only goes to -40F. I need a similar glass thermometer to use to record the minimum temp in a place that could go to -80F. I've found a few alcohol thermometers that will read that low, but none of them will store the minimum temperature (by way of the small index that floats in the column).
I read that canadian weather observers have ones that will record a minimum down to -94F, but I've yet been unable to find any such instrument.
2007-12-21 05:58:09 · 4 answers · asked by treant985 2 in Science & Mathematics ➔ Physics
This thermometer will serve as a back-up for an electronic weather station that will be inaccessible for many months out of the year. I wouldn't want to miss the min. temp recorded because of an equipment failure that couldn't be fixed because I couldn't get to the station.
2007-12-21 06:10:31 · update #1
Min/max is a common feature of indoor/outdoor thermometers based on the mechanical differential expansion of a bimetallic strip. They use a floating mechanical stop to measure max/min. You can probably find one to go that low by scouring the market for weather instruments. Also, as already suggested, consider redundant electronic systems.
2007-12-21 08:16:39 · answer #1 · answered by Frank N 7 · 0⤊ 0⤋
You present an interesting question. At first, I was thinking a thermocouple would do. But, at very low temperatures they are subject to issues with the voltage getting very low. Now, Wikipedia says that NTC thermistors are good down to 10 kelvin - http://en.wikipedia.org/wiki/Thermistor
That is WAY below what you need to measure, so they should do. But, I figure you probably want a commercial product - the thermistor would be more for a project you would design and build. After some digging, it appears that you won't find a glass thermometer for the job. A type K or T thermocouple would do well, though. The type T is more accurate, but K is cheaper. Omega sells them and appropriate readouts that will track lows and highs - http://www.omega.com
Hope this helps!
2007-12-21 06:56:26 · answer #2 · answered by wackyvorlon 3 · 0⤊ 0⤋
Given the price of electronic thermometers these days, why not just use more than one ?
2007-12-21 06:39:45 · answer #3 · answered by Steve T 2 · 0⤊ 0⤋
Use an electronic thermometer. The glass ones are so 18th century.
2007-12-21 06:04:23 · answer #4 · answered by Anonymous · 0⤊ 1⤋