photometer
noun
pho·tom·e·ter
fō-ˈtä-mə-tər 
: an instrument for measuring luminous intensity, luminous flux, illumination, or brightness
Examples of photometer in a Sentence
Recent Examples on the Web
Past attempts with professional-grade hardware include a 1981 experiment that linked an electronic device called a photometer (think of it as a very fancy light meter) with a one-meter infrared telescope in Chile to successfully make daytime observations.
—
Phil Plait, Scientific American, 26 July 2024
Since then, ground controllers have carefully calibrated the observatory's two instruments—a 600-megapixel visible light camera and a 64-megapixel near-infrared spectrograph and photometer.
—Dan Goodin, Ars Technica, 8 Nov. 2023
The network, known as AERONET, contains more than 500 sun photometer instruments that measure global aerosol optical depth.
—Julia Musto, Fox News, 29 June 2023
The kit also includes a Bluetooth ColorQ photometer that gives you a digital readout of your test results.
—Nor'adila Hepburn, Better Homes & Gardens, 1 June 2023
People would come and discuss how to build a really precise photometer.
—Andrew Grant, Discover Magazine, 27 Nov. 2012
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Phil Plait, Scientific American, 26 July 2024
Since then, ground controllers have carefully calibrated the observatory's two instruments—a 600-megapixel visible light camera and a 64-megapixel near-infrared spectrograph and photometer.
—Dan Goodin, Ars Technica, 8 Nov. 2023
The network, known as AERONET, contains more than 500 sun photometer instruments that measure global aerosol optical depth.
—Julia Musto, Fox News, 29 June 2023
The kit also includes a Bluetooth ColorQ photometer that gives you a digital readout of your test results.
—Nor'adila Hepburn, Better Homes & Gardens, 1 June 2023
People would come and discuss how to build a really precise photometer.
—Andrew Grant, Discover Magazine, 27 Nov. 2012
Cite this Entry
“Photometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/photometer. Accessed 31 Oct. 2025.
Copy CitationMedical Definition
photometer
1 of 2 noun
pho·tom·e·ter
fō-ˈtäm-ət-ər
: an instrument for measuring the intensity of light, luminous flux, illumination or brightness by comparison of two unequal lights from different sources usually by reducing the illumination of one (as by varying the distance of the source or using a polarizing device) until the two lights appear equal with the amount of adjustment serving as the basis of comparison and the equality of illumination being judged by various means
photometer
2 of 2 transitive verb
: to examine with a photometer
Love words? Need even more definitions?
Merriam-Webster unabridged
Share