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I am looking for a chemical to use in a freezer down to -10F. I want to leave this liquid in the freezer all the time and stick a thermometer in this liquid to get a quick measurement of the temperature. The liquid can be viscous, but not solid. It should be non-toxic. Do you have any ideas?
Sure, good old ethanol (ethyl alcohol) should do fine. Of course it's
toxic if you drink too much of it, or if you slug down the pure stuff,
but I think that's not the sort of toxicity you were worried about.
If you have trouble finding pure lab ethanol, just start with cheap
vodka. Let the freezer get it as cold as it's going to get. Throw out
the water ice that will form. What's left is a solution concentrated
enough to stay liquid in your freezer.
(published on 10/22/2007)
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