ra·​di·​om·​e·​ter ˌrā-dē-ˈä-mə-tər How to pronounce radiometer (audio)
: an instrument for detecting and usually for measuring the intensity of radiant energy
radiometry noun

Illustration of radiometer

Illustration of radiometer

Example Sentences

Recent Examples on the Web The scanners employ a millimeter wave radiometer which uses radio frequency waves to image visitors. Joseph Calamia, Discover Magazine, 5 Aug. 2010 That includes tools such as a microwave radiometer to quantify the amount of liquid in the atmosphere as well as a LIDAR ceilometer to record the size of clouds. San Diego Union-Tribune, 13 Feb. 2023 The rover also used a magnetometer to test the strength of the asteroid’s magnetic field, and recorded its surface temperature with a high-powered radiometer, which will help determine how well Ryugu holds onto heat. Amber Jorgenson, Discover Magazine, 5 Oct. 2018 Orbiting Jupiter since July 2016, the craft is using its infrared spectrometer and microwave radiometer to search for signs of water and its abundances. Amber Jorgenson, Discover Magazine, 31 Aug. 2018 For example, the spacecraft's microwave radiometer will look into Europa’s crust, obtaining data on its icy composition and temperature. Eric Berger, Ars Technica, 29 Sep. 2022 With the radiometer, the Juno team can create heat maps of Jupiter’s atmospheric layers and look for circular features at different altitudes in the atmosphere, which indicate the presence of a vortex. Katrina Miller, Scientific American, 28 Oct. 2021 This finding emerged from another of Juno’s instruments: a microwave radiometer. Ramin Skibba, Wired, 28 Oct. 2021 To study the Great Red Spot, the Juno probe was reoriented from its normal sideways attitude, so that the microwave radiometer on board could better reveal details of its vertical structure. NBC News, 28 Oct. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radiometer.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History

First Known Use

1875, in the meaning defined above

Time Traveler
The first known use of radiometer was in 1875

Dictionary Entries Near radiometer

Cite this Entry

“Radiometer.” Dictionary, Merriam-Webster, Accessed 22 Mar. 2023.

Kids Definition


ra·​di·​om·​e·​ter ˌrād-ē-ˈäm-ət-ər How to pronounce radiometer (audio)
: an instrument for measuring the strength of radiant energy
radiometry noun

Medical Definition


ra·​di·​om·​e·​ter ˌrād-ē-ˈäm-ət-ər How to pronounce radiometer (audio)
: an instrument for measuring the intensity of radiant energy
also : an instrument for measuring electromagnetic radiation or sound waves

More from Merriam-Webster on radiometer

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