transmittance

noun

trans·​mit·​tance tran(t)s-ˈmi-tᵊn(t)s How to pronounce transmittance (audio)
tranz-
1
2
: the fraction of radiant energy that having entered a layer of absorbing matter reaches its farther boundary

Examples of transmittance in a Sentence

Recent Examples on the Web
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To do so, a roof overhang on the south side provides shade when the sun is high in the summer, and shutters and blinds on both sides of each window regulate the transmittance of heat and provide privacy. IEEE Spectrum, 30 July 2010 Windshield tinting Under Senate Bill 46, vehicle owners are allowed to tint their windshields if the tinting allows 70% light transmittance. Hannah Pinski, The Courier-Journal, 12 July 2024 As the thickness gets closer to a centimeter, light transmittance drops: Berglund’s group reported that 3.7-millimeter-thick wood—roughly two pennies thick—transmitted only 40 percent of light. Jude Coleman, Smithsonian Magazine, 19 Dec. 2023 Made of several layers of materials and fabric, they are designed to provide thermal resistance (known as R-value) and prevent thermal transmittance conductivity (known as U-value). Heidi Wachter, Treehugger, 14 July 2023 The prototype four-pixel device can switch its light transmittance with less than 5 volts in just 625 microseconds—which would translate to more than 1,000 frames per second. IEEE Spectrum, 10 Mar. 2023 The windows are actually translucent panels coated with Nanogel, which yields high levels of thermal insulation and light transmittance. Discover Magazine, 12 Oct. 2015 Thus, in sunlit nesting environments, less pigmentation will increase the detrimental effect of transmittance, but more pigmentation will increase the detrimental effect of absorbance. Seriously Science, Discover Magazine, 1 June 2018 As of right now, the University of Maryland researchers say that their wood achieves a 90 percent transmittance rate for light. Nathaniel Scharping, Discover Magazine, 16 May 2016

Word History

First Known Use

circa 1855, in the meaning defined at sense 1

Time Traveler
The first known use of transmittance was circa 1855

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Cite this Entry

“Transmittance.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/transmittance. Accessed 30 May. 2025.

Medical Definition

transmittance

noun
trans·​mit·​tance -ˈmit-ᵊn(t)s How to pronounce transmittance (audio)
1
2
: the fraction of radiant energy that having entered a layer of absorbing matter reaches its farther boundary
Last Updated: - Updated example sentences
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