Thermal spectrum
Spectrum Spec"trum, n.; pl. {Spectra}. [L. See {Specter}.] 1. An apparition; a specter. [Obs.] [1913 Webster]

2. (Opt.) (a) The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed or studied either as spread out on a screen, by direct vision, by photography, or otherwise. See Illust. of {Light}, and {Spectroscope}. (b) A luminous appearance, or an image seen after the eye has been exposed to an intense light or a strongly illuminated object. When the object is colored, the image appears of the complementary color, as a green image seen after viewing a red wafer lying on white paper. Called also {ocular spectrum}. [1913 Webster]

{Absorption spectrum}, the spectrum of light which has passed through a medium capable of absorbing a portion of the rays. It is characterized by dark spaces, bands, or lines.

{Chemical spectrum}, a spectrum of rays considered solely with reference to their chemical effects, as in photography. These, in the usual photogrophic methods, have their maximum influence at and beyond the violet rays, but are not limited to this region.

{Chromatic spectrum}, the visible colored rays of the solar spectrum, exhibiting the seven principal colors in their order, and covering the central and larger portion of the space of the whole spectrum.

{Continous spectrum}, a spectrum not broken by bands or lines, but having the colors shaded into each other continously, as that from an incandescent solid or liquid, or a gas under high pressure.

{Diffraction spectrum}, a spectrum produced by diffraction, as by a grating.

{Gaseous spectrum}, the spectrum of an incandesoent gas or vapor, under moderate, or especially under very low, pressure. It is characterized by bright bands or lines.

{Normal spectrum}, a representation of a spectrum arranged upon conventional plan adopted as standard, especially a spectrum in which the colors are spaced proportionally to their wave lengths, as when formed by a diffraction grating.

{Ocular spectrum}. See {Spectrum}, 2 (b), above.

{Prismatic spectrum}, a spectrum produced by means of a prism.

{Solar spectrum}, the spectrum of solar light, especially as thrown upon a screen in a darkened room. It is characterized by numerous dark lines called Fraunhofer lines.

{Spectrum analysis}, chemical analysis effected by comparison of the different relative positions and qualities of the fixed lines of spectra produced by flames in which different substances are burned or evaporated, each substance having its own characteristic system of lines.

{Thermal spectrum}, a spectrum of rays considered solely with reference to their heating effect, especially of those rays which produce no luminous phenomena. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Thermal spectrum — Thermal Ther mal, a. [L. thermae hot springs, fr. Gr. ?, pl. of ? heat, fr. ? hot, warm, ? to warm, make hot; perhaps akin to L. formus warm, and E. forceps.] 1. Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. [1913… …   The Collaborative International Dictionary of English

  • thermal spectrum — šiluminės spinduliuotės spektras statusas T sritis fizika atitikmenys: angl. heat retardation spectrum; thermal spectrum vok. Wärmespektrum, n; Wärmestrahlungsspektrum, n rus. спектр теплового излучения, m; теплоспектр, m pranc. spectre de… …   Fizikos terminų žodynas

  • Thermal — Ther mal, a. [L. thermae hot springs, fr. Gr. ?, pl. of ? heat, fr. ? hot, warm, ? to warm, make hot; perhaps akin to L. formus warm, and E. forceps.] 1. Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. [1913 Webster]… …   The Collaborative International Dictionary of English

  • Thermal conductivity — Thermal Ther mal, a. [L. thermae hot springs, fr. Gr. ?, pl. of ? heat, fr. ? hot, warm, ? to warm, make hot; perhaps akin to L. formus warm, and E. forceps.] 1. Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. [1913… …   The Collaborative International Dictionary of English

  • Thermal unit — Thermal Ther mal, a. [L. thermae hot springs, fr. Gr. ?, pl. of ? heat, fr. ? hot, warm, ? to warm, make hot; perhaps akin to L. formus warm, and E. forceps.] 1. Of or pertaining to heat; warm; hot; as, the thermal unit; thermal waters. [1913… …   The Collaborative International Dictionary of English

  • Spectrum — Spec trum, n.; pl. {Spectra}. [L. See {Specter}.] 1. An apparition; a specter. [Obs.] [1913 Webster] 2. (Opt.) (a) The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and observed… …   The Collaborative International Dictionary of English

  • Spectrum analysis — Spectrum Spec trum, n.; pl. {Spectra}. [L. See {Specter}.] 1. An apparition; a specter. [Obs.] [1913 Webster] 2. (Opt.) (a) The several colored and other rays of which light is composed, separated by the refraction of a prism or other means, and… …   The Collaborative International Dictionary of English

  • Thermal radiation — is electromagnetic radiation emitted from the surface of an object which is due to the object s temperature. Infrared radiation from a common household radiator or electric heater is an example of thermal radiation, as is the light emitted by a… …   Wikipedia

  • Thermal infrared spectroscopy — (TIR spectroscopy) is the subset of infrared spectroscopy that deals with radiation emitted in the infrared part of the electromagnetic spectrum. The emitted infrared radiation, though similar to blackbody radiation, is different in that the… …   Wikipedia

  • Thermal desorption spectroscopy — (TDS), also known as temperature programmed desorption (TPD) is the method of observing desorbed molecules from a surface when the surface temperature is increased. Many researchers prefer the name TPD because it is not a spectroscopic… …   Wikipedia

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