Also found in: Thesaurus, Acronyms, Encyclopedia, Wikipedia.
Related to absorptance: transmittance


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

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(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]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(æbˈsɔrp təns, -ˈzɔrp-)

the ratio of the amount of radiation absorbed by a surface to the amount of radiation incident upon it.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
where [tau] is the transmittance of the calorimeter window (unity when no window is used) and a is the absorptance of the cavity.
Although the transmission in the first gap remains zero, the reflectance is not equal to unity because of strong absorptance there.
Throughout the visible range, reflectance is closely associated ([r.sup.2] [is less than] 0.97) with leaf chlorophyll concentration (Gitelson and Merzlyak, 1994; Horler et al., 1983; Knipling, 1970); therefore, lower values indicate higher absorptance of light which is utilized in physiological processes and manifested as higher turf quality.
Textured surfaces are known to scatter the light passing through thin-film solar cells, thereby increasing the optical pathlength in the cells and hence the overall absorptance. Advanced optical modeling predicts that light trapping methods, such as texturing the superstrate of thin-film solar cells, can maintain high photocurrents in very thin a-Si:H solar cells [3].
Calculating the area ratios or absorptance weighted area ratios is easy and fast.
Reflectance in the visible range (400-700 nm) is thus relatively low due to increased chlorophyll absorptance at this range.
from a curve of the absorptance of (1 - [[rho].sup.*]) blackened surface to solar incident angle, which can be applied to Lake.
Raman scattering study was performed on a Jobin Yvon LabRAM HR spectrometer using 514.5 nm irradiation from an argon ion laser at 20 mW Spectral transmittance and absorptance measurements were taken on the samples with a commercial thin film metrology system (Scientific Computing International, FilmTek Par 3000 SE).
(1989), using a pulse amplitude-modulated chlorophyll fluorometer (Schreiber et al., 1986), (ii) measurement of the PPFD at the leaf surface, and (iii) an accurate estimate of leaf absorptance of the incident PPFD.
(86[degrees]F) [C.sup.-1] (0.0331 [degrees][F.sup.-1]) 2 Lighting Load 10,319 W 0.000034 [W.sup.-1] (35209 btu/hr) (0.00001 btu/ [hr.sup.-1]) 3 Equipment Load 90,489 W 0.0000016 [W.sup.-1] (308761 btu/hr) (0.00000047 btu/ [hr.sup.-1]) 4 DOAS supply 13[degrees]C 0.0402[degrees] Temp (55.4[degrees]F) [C.sup.-1] (0.0225 [degrees][F.sup.-1]) 5 DOAS supply 4382 [m.sup.3]/hr 0.000093 [m.sup.3]/ Air Flow (2578 cfm) [hr.sup.-1] (0.000159 [cfm.sup.-1]) 6 Roof-- 5.2833 [m.sup.2]- 0.007941 [m.sup.2]- Insulation K/W (30 [ft.sup.2]- K/[W.sup.-1] (0.0014 hr-F/btu) [ft.sup.2]-hr-F/ [btu.sup.-1]) 7 Roof--color 0.3 0.2052 (Solar Absorptance) 8 Room Temp 23.9[degrees]C 0.15474[degrees] (75[degrees]F) [C.sup.-1] (0.085 [degrees][F.sup.-1]) 9 Occupancy 79 0.0018 S.No.
Figure 3 illustrates the absorptance (A) and EQE of a-[Si.sub.1-x][Ge.sub.x]:H single-junction cells as a function of the p/i grading width.
Another method of assessing plant water status depends on absorptance of light by water at certain near-infrared wavelengths.