| 释义 |
pyrheliometer|pɜːhiːlɪˈɒmɪtə(r)|
[f. Gr. πῦρ fire + ἥλιος sun + -meter.]
An instrument for measuring the amount of heat given off by the sun, by allowing the rays to fall perpendicularly for a given time upon water or mercury in a blackened closed shallow cylindrical vessel, and observing the consequent rise of temperature in the liquid.
1863Tyndall Heat xiii. 391 The radiation from the pyrheliometer is often intercepted, when no cloud is seen. 1871B. Stewart Heat §398 Instruments for measuring the intensity of the sun's radiant heat have been devised by Herschel and Pouillet. The instrument of the latter he calls a pyrheliometer. 1883Science I. 254/1 The new method of deducing the solar constant from pyrheliometer observations at the earth's surface.
Hence pyrhelioˈmetric a., of, pertaining to, or conducted by a pyrheliometer, as pyrheliometric experiments.
1890in Cent. Dict. |