Abstract

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. Scope

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.

ASTM Standards

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

CIE Publications

Keywords

geometric conditions; reflection; transmission;

ICS Code

ICS Number Code 17.180.20 (Colours and measurement of light)

DOI: 10.1520/E0179-12

ASTM International is a member of CrossRef.

ASTM E179