psychrometer Meteorol.
(-ˈɒmɪtə(r))
[f. Gr. ψῡχρό-ς cold + -meter; lit. a measurer of cold, a low-temperature thermometer. Badly employed in current use.]
orig. A thermometer; now, An instrument for measuring the relative humidity of the air; a wet-and-dry-bulb thermometer; a kind of hygrometer.
| 1727–41 Chambers Cycl., Psychrometer, an instrument for measuring the degree of coldness of the air; more usually called thermometer. 1838 Encycl. Brit. (ed. 7) XVII. 533/2 Two thermometers are now mounted on the same scale, and the indications of the wet and dry bulbs seen at the same time. This instrument has been termed a psychrometer. 1876 Davis Polaris Exp. ix. 219 In it were placed the standard thermometer, the wet and dry bulb psychrometers. |
Hence psychroˈmetric, psychroˈmetrical adjs., of or pertaining to the psychrometer or to psychrometry; hygrometrical; psyˈchrometry, the ascertainment of the degree of humidity of the atmosphere by means of a psychrometer.
| 1864 Webster, Psychrometrical instruments... Psychrometrical observations. Psychrometry. 1880 Nature 4 Mar. 426/2 The values deduced..agree with the observed only with a psychrometric difference of 4°. |