I turned the freezer up to 7. I’m sure yours goes to 11, but I am not so lucky. After being turned up to 7, the resulting mean temperature is still too high at 18.8°F. And with that, we bid adieu to our refrigerator. It is around 20 years old—no way to be sure, and it has had a good life. I suppose the EPA would frown on a Viking funeral?
As a final check, I tested the thermometer by running it from a stirred ice bath up to a rolling boil. The ice bath temperature, averaged over about 1 minute, is about 33.1°F. A 1°F error does not present any problems.
Calibration in an ice bath is quite easy, but calibration at boiling is not. The pressure estimated from the RIMU predicts a temperature below the measurement, while the local airport’s barometric pressure predicts one above. In any case, the error is a few percent or less.