Physical Properties
Mercury cannot be used below the temperature at which it becomes solid, -38.83 °C (-37.89 °F). If the thermometer contains nitrogen, the gas may flow down into the column when the mercury solidifies and be trapped there when the temperature rises, making the thermometer unusable until returned to the factory for reconditioning. To avoid this, some weather services require that all mercury-in-glass thermometers be brought indoors when the temperature falls to -37 °C (-34.6 °F). To measure lower meteorological temperatures, a thermometer containing a mercury-thallium alloy which does not solidify until the temperature drops to -61.1 °C (-78 °F) may be used.
Read more about this topic: Mercury-in-glass Thermometer
Famous quotes containing the words physical and/or properties:
“The entire construct of the “medical model” of “mental illness”Mwhat is it but an analogy? Between physical medicine and psychiatry: the mind is said to be subject to disease in the same manner as the body. But whereas in physical medicine there are verifiable physiological proofs—in damaged or affected tissue, bacteria, inflammation, cellular irregularity—in mental illness alleged socially unacceptable behavior is taken as a symptom, even as proof, of pathology.”
—Kate Millett (b. 1934)
“A drop of water has the properties of the sea, but cannot exhibit a storm. There is beauty of a concert, as well as of a flute; strength of a host, as well as of a hero.”
—Ralph Waldo Emerson (1803–1882)