Humboldt State University ® Department of Chemistry

Robert A. Paselk Scientific Instrument Museum

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Laboratory Thermometers


Any chemical laboratory will have a variety of mercury thermometers for monitoring and controlling temperatures. I have selected a two high grade precision laboratory thermometers from the HSU Chemistry Department's collection because of their interest or special qualities: one was N.B.S. Certified, the other came in a wood case (and thus I suspect it is actually from the1940's or 1950'). The thermometers are listed below:
Until precision (constant)-bore tubing became available around 1970, thermometrs had to be made individually. The early references by Minor and Duff below describe thermometer making and calibration prior to constant bore tubing. The modern standardization of thermometers began in the 1880's with the constant-volume hydrogen scale acepted as the standard over the liquid water range in 1887. In 1927 it was replaced by the International Scale using a platinum resistance thermometer for common laboratory temperature ranges. This scale was replaced, after a couple of revisions, in 1990 by ITS-90, a series of four overlapping scales. The normal range of laboratory tempreatures still being based on a platinum resistance thermometer.
Some early descriptions of the thermometer, its calibration and use, are provided below:


Burnett, John in Bud, Robert and Deborah Jean Warner, eds. Instruments of Science: An Historical Encyclopedia. Garland Publishing, Inc. New York (1998) pp 615-8.
Middleton, W. E. Knowles. A History of the Thermometer and Its Uses In Meteorology. Johns Hopkins Press (1966)

From the Analytical/Physical Chemistry Lab - Exhibit Catalog

 HSTC icon
HSTC (1921-34)
HSC 54-73 icon
HSC (1954-1973)
HSC 35-53 icon
HSC (1935-1953)

HSC 1956-72 Instrument Collection

© R. Paselk
Last modified 13 August 2010