[ ak-tuh-nom-i-ter ]
/ ˌæk təˈnɒm ɪ tər /


a device for measuring intensity of radiation, especially that of the sun.
Compare actinograph.

Origin of actinometer

First recorded in 1825–35; actino- + -meter

OTHER WORDS FROM actinometer

ac·tin·o·met·ric [ak-tin-oh-me-trik, ak-tuh-noh-] /ækˌtɪn oʊˈmɛ trɪk, ˌæk tə noʊ-/, ac·tin·o·met·ri·cal, adjectiveac·ti·nom·e·try, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Examples from the Web for actinometer

British Dictionary definitions for actinometer

/ (ˌæktɪˈnɒmɪtə) /


an instrument for measuring the intensity of radiation, esp of the sun's rays

Derived forms of actinometer

actinometric (ˌæktɪnəʊˈmɛtrɪk) or actinometrical, adjectiveactinometry, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for actinometer

[ ăk′tə-nŏmĭ-tər ]

Any of several instruments used to measure radiation, such as a pyrheliometer.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.