actinometer

American  

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

noun

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

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actinometer British  

/ ˌæktɪnəʊˈmɛtrɪk, ˌæktɪˈnɒmɪtə /

noun

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

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actinometer Scientific  

/ ăk′tə-nŏm′ĭ-tər /

1. Any of several instruments used to measure radiation, such as a pyrheliometer.

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Other Word Forms

• actinometric adjective
• actinometrical adjective
• actinometry noun

Etymology

Origin of actinometer

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

Example Sentences

When you get home, the first thing to do is to get hold of a paint box and paint the underside of the glass of your actinometer to match the darkened paper.

From Scientific American Supplement, No. 492, June 6, 1885 by Various

The mystery was not a new type of infernal machine as they imagined but merely a home-made actinometer!

From Sixteen Months in Four German Prisons Wesel, Sennelager, Klingelputz, Ruhleben by Mahoney, Henry Charles

Another object was, to bring down specimens of air from different altitudes, for analysis; to try the effect of the actinometer at great elevations; and to note the hygrometric condition.

From Chambers's Edinburgh Journal, No. 456 Volume 18, New Series, September 25, 1852 by Chambers, Robert

The actinometer indicated an exposure of thirty seconds where in good light one would be right.

From Scientific American Supplement, No. 492, June 6, 1885 by Various

A Johnson's actinometer is very useful to time the exposure.

From Photogravure by Blaney, Henry R.