a. [f. ACTINO- + μετρικός measuring.] Of or pertaining to the measurement of the intensity of the sun’s heat.
1849. Sir J. Herschel, Admiralty Man. Sci. Eng., 295. The ultimate reduction of the actinometric observations.
1881. Eng. Mech., 27 May, 280/1. Some actinometric measurements were made last autumn at different heights in the Alps, by M. Puiseux … The activity of this [vegetation] at Montsouris was proved to be in direct proportion to the actinometric degree.
