Radiometer 839718 219162820 2008-06-13T21:22:35Z VolkovBot 3035831 robot Adding: [[uk:Радіометр]] A '''radiometer''' is a device used to measure the [[radiometry|radiant flux]] or power in [[electromagnetic radiation]]. Although the term is perhaps most generally applied to a device which measures [[infrared radiation]], it can also be applied to detectors operating any wavelength in the [[electromagnetic spectrum]]; a spectrum-measuring radiometer is also called a '''spectroradiometer'''. Whenever describing a radiometer, the most important characteristics are: * spectral range (what wavelengths) * spectral sensitivity (what sensitivity versus wavelength) * field of view (180 degrees or limited to a certain narrow field) * directional response (typically cosine response or uni-directional response) Radiometers can use all kinds of detectors; some are " thermal" that is absorbing energy and converting that to a signal, some sense photons ([[photodiode]]) having a constant response per quantum (light particle). In a common application, the radiation detector within a radiometer is a [[bolometer]] which absorbs the radiation falling on it and, as a result, rises in temperature. This rise can then be measured by a thermometer of some type. This temperature rise can be related to the power in the incident radiation. An early detector of infrared and visible radiation (light) was the [[Crookes radiometer]]. A more sensitive device, employing a different principle, is the [[Nichols radiometer]]. A [[Microwave radiometer]] operates in the [[Microwave]] region of the electromagnetic spectrum. The term '''radiometer''' is occasionally used as shorthand for a [[Crookes_radiometer|Crookes radiometer]], a device in which a rotor with dark and light vanes in a partial vacuum spins when exposed to light. ==See also== * [[Pyranometer]] (instrument) * [[Photometry (optics)]] Main article - explains technical terms and units {{physics-stub}} [[Category:Electromagnetic radiation meters]] [[Category:Radiometry]] ==External links== *[http://www.radiometernewspin.com/ Use of Radiometer as an Alternative Energy Source] [[cs:Radiometr]] [[de:Radiometer]] [[fr:Radiomètre]] [[it:Radiometro]] [[ja:放射計]] [[pl:Radiometr]] [[pt:Radiômetro]] [[ru:Радиометр]] [[fi:Radiometri]] [[sv:Radiometer]] [[uk:Радіометр]]