This guide is intended for use in selecting terminology, measurement scales, and instrumentation for describing or evaluating such appearance characteristics as glossiness, opacity, lightness, transparency, and haziness in terms of reflected or transmitted light. This guide does not consider the spectral variations responsible for color, but the geometric variables described herein can importantly affect instrumentally measured values of color. This guide deals with the reflected and transmitted light and the selection of geometric conditions for its measurement. There are five kinds of measurement scale used in this guide. First is the regular scale which indicates that only light that has been reflected or transmitted without scattering or diffusion is included for measurement. Second is the specular scale which indicates that only the light that is mirror reflected is included for measurement. The third scale is the diffuse scale which indicates that only the light reflected or transmitted in directions other than the specular or regular direction is included in the measurement. The total scale, the fourth scale, indicates that the light reflected or transmitted in all directions is included for measurement. Last is the directional scale which indicates that the light reflected or transmitted in specified directions only is included for measurement. Directional values depend on the illumination and viewing angles and refer to light reflected or transmitted in directions that differ moderately from the centroid direction or axis of the beam. There should be only one aperture stop in any instrument. This stop determines the cross-sectional area of the incident beam on the specimen. All incident rays within the limits of the illuminator aperture angle, and all rays within the receiver aperture angle, should reach the receiver and be given equal weight by the measurement system. When vignetting occurs, the illumination, viewing, and aperture angles do not adequately describe the geometric properties of the instrument. Regularly and diffusely reflected and transmitted light are often not adequately differentiated and identified to enable their separation for measurement. Most objects and material distribute some light both regularly and diffusely; consequently the regular and diffuse components of reflection and transmission cannot be separated precisely for measurement.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 This guide is intended for use in selecting terminology, measurement scales, and instrumentation for describing or evaluating such appearance characteristics as glossiness, opacity, lightness, transparency, and haziness in terms of reflected or transmitted light. This guide does not consider the spectral variations responsible for color, but the geometric variables described herein can importantly affect instrumentally measured values of color. This guide is general in scope rather than specific as to instrument or material.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
C346 Test Method for 45-deg Specular Gloss of Ceramic Materials
C347 Test Method for Reflectivity and Coefficient of Scatter of White Porcelain Enamels
C523 Test Method for Light Reflectance of Acoustical Materials by the Integrating Sphere Reflectometer
C584 Test Method for Specular Gloss of Glazed Ceramic Whitewares and Related Products
D523 Test Method for Specular Gloss
D1003 Test Method for Haze and Luminous Transmittance of Transparent Plastics
D1455 Test Method for 60 Specular Gloss of Emulsion Floor Polish
D1494 Test Method for Diffuse Light Transmission Factor of Reinforced Plastics Panels
D1746 Test Method for Transparency of Plastic Sheeting
D1834 Test Method for 20 Specular Gloss of Waxed Paper
D4039 Test Method for Reflection Haze of High-Gloss Surfaces
D4061 Test Method for Retroreflectance of Horizontal Coatings
E97 Method of Test for Directional Reflectance Factor, 45-Deg 0-Deg, of Opaque Specimens by Broad-Band Filter Reflectometry
E167 Practice for Goniophotometry of Objects and Materials
E284 Terminology of Appearance
E429 Test Method for Measurement and Calculation of Reflecting Characteristics of Metallic Surfaces Using Integrating Sphere Instruments
E430 Test Methods for Measurement of Gloss of High-Gloss Surfaces by Abridged Goniophotometry
E808 Practice for Describing Retroreflection
E809 Practice for Measuring Photometric Characteristics of Retroreflectors
E810 Test Method for Coefficient of Retroreflection of Retroreflective Sheeting Utilizing the Coplanar Geometry
E811 Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime Conditions
E991 Practice for Color Measurement of Fluorescent Specimens Using the One-Monochromator Method
E1164 Practice for Obtaining Spectrometric Data for Object-Color Evaluation
E1331 Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical Geometry
E1348 Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry
E1349 Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45:0 or 0:45) Geometry
E1767 Practice for Specifying the Geometries of Observation and Measurement to Characterize the Appearance of Materials
E2194 Practice for Multiangle Color Measurement of Metal Flake Pigmented Materials
E2539 Practice for Multiangle Color Measurement of Interference Pigments
F768 Test Method for Specular Reflectance and Transmittance Measurements of Optically Flat-Coated and Non-Coated Specimens
CIEPublicationNo.38 Radiometric and Photometric Characteristics of Materials and Their Measurement, 1977
geometric conditions; reflection; transmission;
ICS Number Code 17.180.20 (Colours and measurement of light)
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