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Related to absorptance: transmittance


 (əb-zôrp′təns, -sôrp′-)
The ratio of absorbed to incident radiation.


(əbˈsɔːptəns; -ˈzɔːp-) or

absorption factor

(General Physics) physics a measure of the ability of an object to absorb radiation, equal to the ratio of the absorbed radiant flux to the incident flux. For a layer of material the ratio of the flux absorbed between the entry and exit surfaces of the layer to the flux leaving the entry surface is the internal absorptance. Symbol: α Compare reflectance, transmittance
[C20: absorption + -ance]


(æbˈsɔrp təns, -ˈzɔrp-)

the ratio of the amount of radiation absorbed by a surface to the amount of radiation incident upon it.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.absorptance - a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substanceabsorptance - a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber; "absorptance equals 1 minus transmittance"
coefficient - a constant number that serves as a measure of some property or characteristic
References in periodicals archive ?
In general, intact and de-trichomed leaflets had the highest reflectance and transmittance and the lowest absorptance at ca.
The absorptance spectra of the erbium-doped samples are shown in Fig.
Four correction factors were used: the LOCR window transmittance (TW), the LOCR receiver absorptance (AR), the relative aperture transmittance (TA), and the LOCR electrical calibration (kL).
2001), the correlation of absorptance of light with anthocyanin extracts and leaves from plants exposed to different levels of cold-induced photoinhibition (Pietrini & Massacci, 1998), and anthocyanin development in conjunction with the development of other mechanisms of photoprotection such as wax (Barker et al.
The collector fin efficiency factor, the emittance, and the absorptance of the absorber plate were 0.
010 Cavity Absorptance Nonequivalance Temperature Gradiants Heater Power [V.
Automated roller shades with three shade fabrics (absorptance = 18%, 23% and 27% and constant reflectance = 70%) were tested and compared to two different arrangements of the advanced system for a single shade fabric with an absorptance, [alpha] = 23%.
Since the solar absorptance and the longwave emittance of the same surface can be quite different, the shortwave and the longwave radiative fractions should be used separately to better reflect actual radiation interchanges in the room.
Both can be used for the electrical substitution equivalence measurement and their separate positions allow checking the effectiveness of the heating system for equivalence of optical and electrical power absorptance by the cavity.
ir] were the mean radiant temperature, unirradiated mean radiant temperature, the projected area factor, the absorptance of radiant heat, and the radiant heat flux density, respectively.