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Integrating Sphere
An integrating sphere (also known as an Ulbricht sphere) is an optical component consisting of a hollow spherical cavity with its interior covered with a diffuse reflection, diffuse white reflective coating, with small holes for entrance and exit ports. Its relevant property is a uniform scattering or diffusing effect. Light rays incident on any point on the inner surface are, by multiple scattering reflections, distributed equally to all other points. The effects of the original direction of light are minimized. An integrating sphere may be thought of as a diffuser (optics), diffuser which preserves power but destroys spatial information. It is typically used with some light source and a detector for optical power measurement. A similar device is the focusing or Coblentz sphere, which differs in that it has a mirror-like (specular) inner surface rather than a diffuse inner surface. In 1892, W. E. Sumpner published an expression for the throughput of a spherical enclosure with di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminance Chamber
Luminance is a Photometry (optics), photometric measure of the luminous intensity per units of measurement, unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle. The procedure for conversion from spectral radiance to luminance is standardized by the International Commission on Illumination, CIE and International Organization for Standardization, ISO. Brightness is the terminology, term for the ''subjective'' impression of the ''objective'' luminance measurement standard (see for the importance of this contrast). The SI base unit, SI unit for luminance is candela per square metre (cd/m2). A non-SI term for the same unit is the nit (unit), nit. The unit in the Centimetre–gram–second system of units, Centimetre–gram–second system of units (CGS) (which predated the SI system) is the stilb (luminance), stilb, which is equal to o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leonard Hanssen
Leonard Hanssen is an American physicist at the National Institute of Standards and Technology (NIST). He is the project leader for infrared spectrophotometry in the Sensor Science Division of the Physical Measurement Laboratory. Hanssen is responsible for the realizing and maintaining NIST's scales for spectral reflectance, transmittance, and emittance of materials at infrared wavelengths. He is an expert in infrared spectrophotometry and integrating sphere design and applications. Education Hanssen earned B.S. degrees in physics and mathematics at Seattle University. He completed an M.S. in physics and a Ph.D. in experimental physics at Cornell University. His 1985 dissertation was titled ''IR surface electromagnetic-wave measurement of hydrogen adsorption and surface reconstruction on W(100)''. Career Following the completion of his Ph.D., Hanssen worked at TRW Defense and Space Systems, Sachs Freeman Associates, and the Naval Research Laboratory. In 1990, Hanssen move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometry
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Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electromagnetic radiation * A photometric study, sometimes also referred to as a lighting "layout" or "point by point" See also * Photogrammetry * Radiometry Radiometry is a set of techniques for measurement, measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power (physics), power in space, as opposed to phot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Journal Of Physics
The ''American Journal of Physics'' is a monthly, peer-reviewed scientific journal published by the American Association of Physics Teachers and the American Institute of Physics. The editor-in-chief is Beth Parks of Colgate University."Current Frequency: Monthly, 2002; and Former Frequency varies, 1940-2001" Confirmation of Editor, ISSN, CODEN, and other relevant information. Aims and scope The focus of this journal is undergraduate and graduate level physics. The intended audience is college and university physics teachers and students. Coverage includes current research in physics, instructional laboratory equipment, laboratory demonstrations, teaching methodologies, lists of resources, and book reviews. In addition, historical, philosophical and cultural aspects of physics are also covered. According to the 2021 Journal Citation Reports from Clarivate, this journal has a 2020 impact factor of 1.022. History The former title of this journal was ''American Physics Teach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambert's Cosine Law
In optics, Lambert's cosine law says that the observed radiant intensity or luminous intensity from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle ''θ'' between the observer's line of sight and the surface normal; .RCA Electro-Optics Handbook, p.18 ffModern Optical Engineering, Warren J. Smith, McGraw-Hill, p. 228, 256 The law is also known as the cosine emission law or Lambert's emission law. It is named after Johann Heinrich Lambert, from his '' Photometria'', published in 1760. A surface which obeys Lambert's law is said to be ''Lambertian'', and exhibits Lambertian reflectance. Such a surface has a constant radiance/luminance, regardless of the angle from which it is observed; a single human eye perceives such a surface as having a constant brightness, regardless of the angle from which the eye observes the surface. It has the same radiance because, although the emitted power from a given area ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TU Dresden
TU Dresden (for , abbreviated as TUD), also as the Dresden University of Technology, is a public research university in Dresden, Germany. It is the largest institute of higher education in the city of Dresden, the largest university in Saxony and one of the 10 largest universities in Germany with 32,389 students . The name Technische Universität Dresden has only been used since 1961; the history of the university, however, goes back nearly 200 years to 1828. This makes it one of the oldest colleges of technology in Germany, and one of the country's oldest universities, which in German today refers to institutes of higher education that cover the entire curriculum. The university is a member of TU9, a consortium of the nine leading German Institutes of Technology. The university is one of eleven German universities which succeeded in the German Universities Excellence Initiative, Excellence Initiative in 2012, thus getting the title of a "University of Excellence". The TU Dresde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Flux
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of electromagnetic radiation (including infrared, ultraviolet, and visible light), in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. Units The SI unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian. 1\ \text = 1\ \text \times 1\ \text In other systems of units, luminous flux may have units of power. Weighting The luminous flux accounts for the sensitivity of the eye by weighting the power at each wavelength with the luminosity function, which represents the eye's response to different wavelengths. The luminous flux is a weighted sum of the power at all wavelengths in the visible band. Light outside the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectralon
Spectralon is a fluoropolymer that has the highest diffuse reflectance of any known material or coating over the ultraviolet, visible, and near-infrared regions of the spectrum. It is the whitest substance available and reflects 99% of the light. It exhibits highly Lambertian behavior, and can be machined into a wide variety of shapes for the construction of optical components such as calibration targets, integrating spheres, and optical pump cavities for lasers. Characteristics Spectralon's reflectance generally exceeds 99 percent over a range from 400 to 1500 nm and 95 percent from 250 to 2500 nm; however, grades are available with added carbon to achieve various gray levels. The material consists of PTFE powder that has been compressed into solid forms and sintered for stability, with approximately 40 percent void volume to enhance scattering of light. Surface or subsurface contamination may lower the reflectance at the extreme upper and lower ends of the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTFE
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally invented the compound in 1938. Polytetrafluoroethylene is a fluorocarbon solid, as it is a high- molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low electric polarizability of fluorine. PTFE has one of the lowest coefficients of friction of any solid. Polytetrafluoroethylene is used as a non-stick coating for pans and other cookware. It is non-reactive, partly because of the strength of carbon–fluorine bonds, so it is often used in containers and pipework for reactive and corrosive chemicals. When used as a lubricant, PTFE reduces fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Sulfate
Barium sulfate (or sulphate) is the inorganic compound with the chemical formula Ba SO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs in nature as the mineral barite, which is the main commercial source of barium and materials prepared from it. Its opaque white appearance and its high density are exploited in its main applications.Holleman, A. F. and Wiberg, E. (2001) ''Inorganic Chemistry'', San Diego, CA. Academic Press, . Uses Drilling fluids About 80% of the world's barium sulfate production, mostly purified mineral, is consumed as a component of oil well drilling fluid. It increases the density of the fluid, increasing the hydrostatic pressure in the well and reducing the chance of a blowout. Radiocontrast agent Barium sulfate in suspension is often used medically as a radiocontrast agent for X-ray imaging and other diagnostic procedures. It is most often used in imaging of the GI tract during what is colloquially known as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Oxide
Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to remove moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from Magnesia), to differentiate it from '' magnesia nigra'', a black mineral containing what is now known as manganese. Related oxides While "magnesium oxide" normally refers to MgO, the compound magnesium peroxide MgO2 is also known. According to evolutionary crystal structure prediction, MgO2 is thermodynamically stable at pressures above 116 GPa (gigapascals), and a semiconducting suboxide Mg3O2 is thermodynamically stable above 500 GPa. Because of its stability, MgO is used as a mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Integrating Sphere
Commercial may refer to: * (adjective for) commerce, a system of voluntary exchange of products and services ** (adjective for) trade, the trading of something of economic value such as goods, services, information or money * a dose of advertising conveyed through media (such as radio or television) ** Radio advertisement ** Television advertisement * Two functional constituencies in elections for the Legislative Council of Hong Kong: **Commercial (First) **Commercial (Second) * ''Commercial'' (album), a 2009 album by Los Amigos Invisibles * Commercial broadcasting * Commercial style or early Chicago school, an American architectural style * Commercial Drive, Vancouver, a road in Vancouver, British Columbia, Canada * Commercial Township, New Jersey, in Cumberland County, New Jersey See also * * Comercial (other), Spanish and Portuguese word for the same thing * Commercialism Commercialism is the application of both manufacturing and consumption towards personal usag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
