Absolute reflectance value--Reflectance value relative to the perfectly reflecting and perfectly diffusing surface as 100.00
Absorption--Process by which light or other electromagnetic radiation is converted into heat or other radiation when incident on or passing through material.
Accuracy--Conformity of a measured result to an accepted reference value or scale.
Achromatic color--A neutral color, such a white, gray, or black, that has no hue. This color may also be termed nonchromatic.
Angle of incidence--Angle between the axis of an impinging light beam and a perpendicular to the specimen surface.
Angle of view--Angle between the axis of observation and perpendicular to the specimen surface.
Artificial illuminants--A synthetic light source that has spectral distribution as close as possible to that of the natural illuminant being duplicated. In most cases the natural illuminant is daylight.
Attribute--A distinguishing characteristic of a sensation, perception, or mode of appearance. A distinction exists between chromatic and geometric appearance attributes.
Beer's law--The transmittance of a stable solution is an exponential function of the product of concentration and length of path in the solution.
Blackbody--A body that absorbs all the radiation falling on it and reflects none.
Blackbody radiator--A thermal radiator of uniform temperature whose radiant existence in all parts of the spectrum is the maximum obtainable from any thermal radiator at the same temperature.
Brightness--An optics and appearance attribute of visual sensation by which an observer is aware of the differences in luminance or lightness and saturation.
Chromatic--That which is perceived as having a hue (not white, gray, or black).
Chromatic attributes--Hue and chroma (saturation).
Chromaticity--The part of the color specification that does not involve luminance. Chromaticity is two-dimensional and is specified by pairs of …