actinometer
(ak′tə näm′ət ər)
noun
- Physics an instrument for measuring the intensity of the sun's rays, or the actinic effect of light rays
- Photog. exposure meter
See actinometer in American Heritage Dictionary 4
noun Any of several radiometric instruments, such as a pyrheliometer, used chiefly for meteorological measurements of terrestrial and solar radiation.
Related Forms:
- acˌti·no·metˈric (-nō-mĕtˈrĭk), acˌti·no·metˈri·cal adjective
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