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 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

The University of Bern has provided a powerful photometer for the telescope.

From BBC

He just needed a photometer 1000 times more sensitive than any available.

From Science Magazine

Earth appears so bright because Kepler's light-sensing photometer is exquisitely sensitive.

From Scientific American

For each sample, I use a refractometer, which measures moisture content, a pH meter for acidity, a honey color photometer, and other instruments that measure acidity and viscosity.

From New York Times