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.

---

actinometer British  

/ ˌæktɪnəʊˈmɛtrɪk, ˌæktɪˈnɒmɪtə /

noun

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

---

actinometer Scientific  

/ ăk′tə-nŏm′ĭ-tər /

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

---

Other Word Forms

• actinometric
  adjective
• actinometrical
  adjective
• actinometry
  noun

Etymology

Origin of actinometer

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

Example Sentences

You may sometimes find that the actinometer indicates a very different exposure from what the eye would lead you to expect.

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

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 selenium actinometer has been described in the Comptes Rendus in a communication from M. Morize, of Rio de Janeiro.

From Scientific American Supplement, No. 484, April 11, 1885 by Various

The actinometer of M. Violle is, in principle, a sphere of copper, blackened externally, and having inside a thermometric apparatus which registers some distance away.

From Sounding the Ocean of Air by Rotch, A. Lawrence

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

From Photogravure by Blaney, Henry R.