| 释义 |
radiometryenUK
ra·di·om·e·ter R0015900 (rā′dē-ŏm′ĭ-tər)n.1. A device that measures the intensity of radiant energy, consisting of a partially evacuated glass bulb containing lightweight vertical vanes, each blackened on one side, suspended radially about a central vertical axis to permit their revolution about the axis as a result of incident radiation. Also called light mill.2. An instrument that detects electromagnetic radiation.
ra′di·o·met′ric (-ō-mĕt′rĭk) adj.ra′di·om′e·try n.radiometrythe measurement of radiant energy by means of a radiometer, an instrument composed of vanes which rotate at speeds proportionate to the intensity of the energy source. — radiometric, adj.See also: Physics
the measurement of radiant energy by means of a radiometer. — radiometric, adj.See also: Sun
the measurement of radiant energy by means of a radiometer. — radiometric, adj.See also: MeasurementTranslationsradiométrieradiometriaрадиометрия
radiometryenUK
Radiometry A branch of science that deals with the measurement or detection of radiant electromagnetic energy. Radiometry is divided according to regions of the spectrum in which the same experimental techniques can be used. Thus, vacuum ultraviolet radiometry, intermediate-infrared radiometry, far-infrared radiometry, and microwave radiometry are considered separate fields, and all of these are to be distinguished from radiometry in the visible spectral region. Curiously, radiometry in the visible is called radiometry, optical radiation measurement science, or photometry, but it is not called visible radiometry. See Electromagnetic radiation, Infrared radiation, Light, Ultraviolet radiation Any radiation detector (such as a thermometer) that responds to an increase in temperature caused by the absorption of radiant energy is known as a thermal detector. Similarly, any detector (such as a photochemical reaction) that responds to the excitation of a bound electron is called a photon or quantum detector. Liquid-in-glass thermometers are sluggish and relatively insensitive. The key to developing thermal detectors with better performance than liquid-in-glass thermometers has been to secure a large and rapid rise in temperature associated with a high sensitivity to temperature changes. Thermal detectors have been based upon a number of different principles. Radiation thermocouples produce a voltage, bolometers undergo a change in resistance, pyroelectric detectors undergo a change in spontaneous electric polarization, and the gas in pneumatic detectors (Golay cells) and photoacoustic detectors expands in response to incident radiation. The periodic expansion and contraction of the gas in response to high-frequency modulated radiation is detected by a sensitive microphone in the case of the photoacoustic detector. The Golay cell, on the other hand, uses a sensitive photomultiplier and a reference beam of light to detect distortion of a flexible membrane mirror caused by the expansion and contraction of the gas. See Bolometer, Pyroelectricity, Thermocouple The main problem with thermal detectors is that they respond not only to electromagnetic radiation but to any source of heat. This makes their design, construction, and use rather difficult, because they must be made sensitive to the radiation of interest while remaining insensitive to all other sources of heat, such as conduction, convection, and background radiation, that are of no interest in the particular measurement. Photon detectors respond only to photons of electromagnetic radiation that have energies greater than some minimum value determined by the quantum-mechanical properties of the detector material. Since heat radiation from the environment at room temperature consists of infrared photons, photon detectors for use in the visible can be built so that they do not respond to any source of heat except the radiation of interest. Following the introduction of planar silicon technology for microelectronics, the same technology was quickly exploited to make planar photodiodes based on the internal photoelectric effect in silicon. In these devices, the separation of a photogenerated electron-hole pair by the built-in field surrounding the p+n junction induces the flow of one electron in an external short circuit (such as the inputs to an operational amplifier) across the electrodes. The number of electrons flowing in an external short circuit per absorbed photon is called the quantum efficiency. The use of these diodes has grown to the point where they are the most widely used detector for the visible and nearby spectral regions. Their behavior as a radiation detector in the visible is so nearly ideal that they can be used as a standard, their cost is so low that they can be used for the most mundane of applications, and their sensitivity is so high that they can be used to measure all but the weakest radiation (which requires the most sensitive photomultipliers). See Semiconductor diode Research efforts have been directed at producing photon detectors based on more exotic semiconductors, and more complicated structures to extend the sensitivity, time response, and spectral coverage. radiometry[‚rād·ē′äm·ə·trē] (physics) The detection and measurement of radiant electromagnetic energy, especially that associated with infrared radiation. MedicalSeeradiometerradiometer (redirected from radiometry)
Words related to radiometernoun meter to detect and measure radiant energy (electromagnetic or acoustic)Related Words- Crookes radiometer
- meter
- radiomicrometer
- Rayleigh disk
References in periodicals archiveIt lacked the advanced radiometry that would accurately gaugeMINI METEOROLOGISTS: How Innovations in Satellite Technology Are Reducing Weather RisksChive, "Temperature control and thermal dosimetry by microwave radiometry in hyperthermia," IEEE Transactions on Microwave Theory and Techniques, Vol.Microwave Non-invasive Temperature Monitoring Using UWB Radar for Cancer Treatment by HyperthermiaOne solution that is rapidly gaining acceptance in the industry is equipping a fleet of small satellites with state-of-the art passive microwave radiometry technology that gives scientists and forecasters unprecedented insights into climactic conditions.Advanced Climate Analytics: New Approaches for Managing RiskGrant, The Art of Radiometry, SPIE Press, Bellingham, WA, USA, 2010.Quantification of the Transparency of the Transparent Soil in Geotechnical ModelingFeasibility of noninvasive measurement of deep brain temperature in newborn infants by multifrequency microwave radiometry. IEEE Transactions on Microwave Theory and Techniques 48, 2141-2147.The effect of intermittent head cooling on aerobic performance in the heatVolume I: microwave remote sensing fundamentals and radiometry.," Microwave remote sensing: active and passive.Climatological Behavior of Precipitating Clouds in the Northeast Region of BrazilThe most important granitic rocks in the Czech Republic occur mainly as Variscan intrusions (the absolute age of these intrusions is 340-250 Ma, measured by radiometry) (Chlupac et al., 2011).Characterizing gas permeability and pore properties of Czech granitic rocksRadiometry of boreholes (in Russian), NEDRA, Moscow.Petrophysical analysis of the reservoir intervals in Kahi-01 well, Kohat Sub-Basin, PakistanRFI is a growing problem in radiometry due to increasing demand for use on the spectrum for communications.New cubesats to test earth science tech in spaceCSAR is at the heart of a space mission like no other--a standards lab in space called the Traceable Radiometry Underpinning Terrestrial--and Helio-Studies or Truths.The unarguable truthsMicrowave radiometry, implemented in radioastronomy, is a passive technique for measuring thermal radiation, emitted by an object.Waves, oscillations and optics in biomedical engineering: research in the Department of Biomedical Engineering 1994-2014Irvine, CA, June 07, 2014 --(PR.com)-- Pasternack Enterprises, Inc., an industry leading manufacturer and supplier of RF, microwave and millimeter wave products, releases a new family of high frequency, WR-15 waveguide antennas, which are perfectly designed for high-bandwidth applications including point-to-point links, GigE wireless LAN, millimeter radiometry, uncompressed HD video, FMCW radar, millimeter scintillometry, campus networks, and multi-gigabit wireless communications.
Offered in this release are four high gain WR-15 horn antennas operating between 50 GHz and 70 GHz and are available in 20 dBi, 24 dBi, 34 dBi and 42 dBi gain models.Pasternack Releases New Family of Millimeter Wave AntennasIn the future, the institute also hopes to expand its capabilities into chemical metrology, nanometrology, photometry, radiometry, acoustics, radio frequency, microwave and hardness.National institution launched to ensure accurate measurementsGround-based Microwave Radiometry and Remote Sensing: Methods and ApplicationsGround-based Microwave Radiometry and Remote Sensing: Methods and ApplicationsUnder the reorganization, NIST expanded the radiometry and optical characterization facilities.Optical passive sensor calibration for satellite remote sensing and the legacy of NOAA and NIST cooperation |