photometer

American  

[foh-tom-i-ter] / foʊˈtɒm ɪ tər /

noun

Optics.

1. an instrument that measures luminous intensity or brightness, luminous flux, light distribution, color, etc., usually by comparing the light emitted by two sources, one source having certain specified standard characteristics.

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photometer British  

/ fəʊˈtɒmɪtə /

noun

1. an instrument used in photometry, usually one that compares the illumination produced by a particular light source with that produced by a standard source See also spectrophotometer

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Etymology

Origin of photometer

From the New Latin word photometrum, dating back to 1770–80. See photo-, -meter

Example Sentences

Euclid launched in July to probe the fine details of this sprawling structure with a state-of-the-art 600-megapixel visible-light camera and a wide-field near-infrared spectrometer and photometer.

From Scientific American • Nov. 8, 2023

Euclid also has a near-infrared spectrometer and photometer for measuring each galaxy’s redshift, or the wavelength-stretching effect that occurs in light arriving from the faraway cosmos.

From New York Times • Jul. 1, 2023

Using an instrument called a photometer, which measures brightness very accurately, researchers can detect those dips and—from their duration and frequency—can deduce the size of the exoplanet and its orbit.

From Science Magazine • Jan. 14, 2015

The machines, like the electronic nose or the laser-wielding robot that measures atmospheric ozone 10 kilometers up known as the sun photometer, constantly monitor air quality from 17 different sites.

From Scientific American • Jan. 8, 2013

By a good light the exposure on the shade does not exceed twenty minutes with a pretty intense transparency, and should be regulated with a photometer.

From Photographic Reproduction Processes by Duchochois, Peter C.