photometer

American

[foh-tom-i-ter] / foʊˈtɒm ɪ tər /

noun

Optics.

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.

photometer British

/ fəʊˈtɒmɪtə /

noun

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

"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

Etymology

Origin of photometer

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

One thing she’s noticed: how an outfit looks in a photo matters.

From Los Angeles Times • Aug. 1, 2025

In a time of dwindling classical sales and releases, she was able to choose the selections and even the cover photo, matters subject to a collaboration on Sony recordings.

From Seattle Times • Dec. 30, 2022

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023