1、Designation:E17996(Reapproved2003) Designation: E179 12Standard Guide forSelection of Geometric Conditions for Measurement ofReflection and Transmission Properties of Materials1This standard is issued under the fixed designation E179; the number immediately following the designation indicates the ye
2、ar oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis is a guide describing the selecting of geometric
3、conditions of measurement of appearanceattributes such as color, gloss, reflectance, opacity, and transmittance. It includes a selection ofnumerical scales for appearance attributes other than color.In describing appearance, wavelength (or spectral) variability is primarily responsible for color,whi
4、le geometric (or directional) selectivity is primarily responsible for gloss, luster, translucency, andlike attributes. However, geometric conditions not only affect geometric variables such as gloss andtransparency, but also affect color, diffuse reflectance, and transmittance. Likewise spectral co
5、nditionscan affect the measurement of geometric attributes of appearance. Therefore both the spectral andgeometric conditions of measurement must be identified in specifying an appearance attribute of aspecimen.This guide describes the selection of geometric conditions and as a consequence should he
6、lpimprove agreement in these measurements as well as providing useful guidance in resolvingdifferences between spectral-type measurements that are related to geometry.1. Scope1.1 This guide is intended for use in selecting terminology, measurement scales, and instrumentation for describing orevaluat
7、ing such appearance characteristics as glossiness, opacity, lightness, transparency, and haziness in terms of reflected ortransmitted light. This guide does not consider the spectral variations responsible for color, but the geometric variables describedherein can importantly affect instrumentally m
8、easured values of color. This guide is general in scope rather than specific as toinstrument or material.2. Referenced Documents2.1 ASTM Standards:2C346 Test Method for 45-deg Specular Gloss of Ceramic MaterialsC347 Test Method for Reflectance, Reflectivity, and Coefficient of Scatter of White Porce
9、lain Enamels3C523 Test Method for Light Reflectance of Acoustical Materials by the Integrating Sphere ReflectometerC584 Test Method for Specular Gloss of Glazed Ceramic Whitewares and Related ProductsD523 Test Method for Specular GlossD1003 Test Method for Haze and Luminous Transmittance of Transpar
10、ent PlasticsD1455 Test Method for 60 Specular Gloss of Emulsion Floor PolishD1494 Test Method for Diffuse Light Transmission Factor of Reinforced Plastics PanelsD1746 Test Method for Transparency of Plastic SheetingD1834 Test Method for 20 Specular Gloss of Waxed PaperD4039 Test Method for Reflectio
11、n Haze of High-Gloss SurfacesD4061 Test Method for Retroreflectance of Horizontal Coatings1This guide is under the jurisdiction of ASTM Committee E12 on Color and Appearance and is the direct responsibility of Subcommittee E12.03 on Geometry.Current edition approved Jan. 10, 2003. Published March 20
12、03. Originally approved in 1961. Last previous edition approved in 1996 as E17996. DOI:10.1520/E0179-96R03.Current edition approved July 1, 2012. Published September 2012. Originally approved in 1961. Last previous edition approved in 2003 as E179 96 (2003) which waswithdrawn April 2012 and reinstat
13、ed in July 2012.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Withdrawn. The last approved version of th
14、is historical standard is referenced on www.astm.org.1This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes ac
15、curately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United S
16、tates.E97 Test Method of Test for Directional Reflectance Factor, 45-deg, 0-deg,45-Deg 0-Deg, of Opaque Specimens by Broad-BandFilter ReflectometryE167 Practice for Goniophotometry of Objects and MaterialsE284 Terminology of AppearanceE429 Test Method for Measurement and Calculation of Reflecting Ch
17、aracteristics of Metallic Surfaces Using Integrating SphereInstrumentsE430 Test Methods for Measurement of Gloss of High-Gloss Surfaces by Abridged GoniophotometryE808 Practice for Describing RetroreflectionE809 Practice for Measuring Photometric Characteristics of RetroreflectorsE810 Test Method fo
18、r Coefficient of Retroreflection of Retroreflective Sheeting Utilizing the Coplanar GeometryE811 Practice for Measuring Colorimetric Characteristics of Retroreflectors Under Nighttime ConditionsE991 Practice for Color Measurement of Fluorescent Specimens Using the One-Monochromator MethodE1164 Pract
19、ice for Obtaining Spectrometric Data for Object-Color EvaluationE1331 Test Method for Reflectance Factor and Color by Spectrophotometry Using Hemispherical GeometryE1348 Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical GeometryE1349 Test Method for Reflectance Factor
20、and Color by Spectrophotometry Using Bidirectional (45:0 or 0:45) GeometryE1767 Practice for Specifying the Geometries of Observation and Measurement to Characterize the Appearance of MaterialsE2194 Practice for Multiangle Color Measurement of Metal Flake Pigmented MaterialsE2539 Practice for Multia
21、ngle Color Measurement of Interference PigmentsF768 Method for Specular Reflectance and Transmittance Measurements of Optically Flat-Coated and Non-Coated Specimens02.2 CIE Publications:4CIE Publication No. 15.2 Colorimetry, second edition 1986CIE Publication No. 17.4 International Lighting Vocabula
22、ry, fourth edition, 1987CIE Publication No. 38 Radiometric and Photometric Characteristics of Materials and Their Measurement, 19773. Terminology3.1 Definitions:3.1.1 flux (radiant), Fflux (radiant), F, nthe time rate of flow of radiant energy; radiant power (Terminology E284).3.1.2 incident flux, F
23、ii, nflux incident on the specimen at a specified illumination angle and aperture angle.3.1.3 reflected flux, Fr, nflux reflected from the specimen at a specified viewing angle and aperatureaperture angle.3.1.4 reference reflected flux, Fr.rr.r, nflux reflected from a reference standard of reflectan
24、ce, illuminated and viewed in thesame manner as the specimen under consideration.3.1.5 transmitted flux, Ftt, nflux transmitted through the specimen at a specified viewing angle and field angle.3.1.6 reflectance, rreflectance, r, nratio of the reflected flux to the incident flux defined as r = Fr/ F
25、i.3.1.7 reflectance factor, Rreflectance factor, R, nratio of the reflected flux to the reference reflected flux defined as R=Fr/Fr.r.3.1.8 transmittance, ttransmittance, t, nratio of the transmitted flux to the incident flux defined as t = Ft/ Fi.3.1.8.1 DiscussionA companion term, transmittance fa
26、ctor, is not normally used in the measurement of appearance attributes.3.1.9 For other definitions see Terminology E284 and CIE Publication Nos. 17.4 and 38 and 38.4. Summary of Guide4.1 When light impinges upon a material, several phenomena can occur. Part of the light may be reflected, part may be
27、transmitted, and part may be absorbed. This guide deals with the reflected and transmitted light and the selection of geometricconditions for its measurement.4.2 An idealization of the light reflected and transmitted by a material is shown in Fig. 1. Fig. 2 illustrates luminancedistributions more li
28、ke those actually encountered in practice.5. Types of Measurement Scales5.1 Type of ScaleThe terms defined in 3.1.6-3.1.8 to may be further identified by a preceding adjective, such as specular,regular, diffuse, total, or directional, thereby identifying the basis for the measurement scale. The sign
29、ificance of each of theseadjectives is as follows:5.1.1 regularindicates that only light that has been reflected or transmitted without scattering or diffusion is included formeasurement. When a specimen scatters or diffuses the incident light on reflection or transmission, the values obtained will
30、dependon the angular size of the illuminator and receiver used in the measurement.5.1.2 specularindicates that only the light that is mirror-reflected is included for measurement. The CIE prefers the modifierregular instead of specular although specular reflectance is recognized. Specular has also s
31、ometimes been used to refer to regular4Information on how to obtain CIE documents should be requested from the U.S. National Committee, CIE, c/o Radiometric Physics Division, National Institute ofStandards and Technology, Bldg. 220, Room B-306, Gaithersburg, MD 20899.E179 122transmittance. This is a
32、 misnomer because specular refers to a mirror.5.1.3 diffuseindicates that only the light reflected or transmitted in directions other than the specular or regular direction isincluded in the measurement.NOTE 1The differences between the concepts of regular and diffuse components of reflection and tr
33、ansmission are shown in Table 1.FIG. 1 Idealizations of Reflection and Transmission Phenomena,Showing ComponentsFIG. 2 Representations of Actual Reflection and TransmissionPhenomena with Mixtures of ComponentsTABLE 1 Differences Between Concepts of Regular (Specular)and Diffuse Components of Reflect
34、ion and TransmissionMeasurementGeometricDistribution ofLightStructuralElementsResponsibleResultingAppearanceCharacteristicWhenComponentDominatesReflectance:Specularcomponentreflected only indirection of mirrorreflectionsmoothness of surfaceor skin of specimenglossiness orshininessDiffusecomponentdis
35、tributed in alldirectionspigment granules andcavities withinspecimen, surfaceroughnesslightness(expressed onblack-gray-whitescale)Transmittance:Regularcomponenta continuation of theincident beamclear homogeneousmedium with plane,parallel facesclearness ortransparencyDiffusecomponentdistributed in al
36、ldirectionsscattering andrefracting particles of anonopaque specimen,surface roughnesstranslucency,turbidity, orhazinessE179 1235.1.4 totalindicates that the light reflected or transmitted in all directions is included for measurement.5.1.5 directionalindicates that the light reflected or transmitte
37、d 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 differmoderately from the centroid direction or axis of the beam.6. Geometric Directions of Incidence and Viewing
38、6.1 Geometric directions may be identified by preceding the adjective with the angular directions, by including a detailedgeometric description, or by placing after the symbols a subscript that represents the measurement condition.NOTE 2This guide is concerned with bidirectional or hemispherical mea
39、surement systems. For gonophotometric methods, see Practice E167. Formethods of specifying the geometry of measurements, see Practice E1767.6.2 illumination and viewing anglesthe angles of illumination and viewing are identified as follows (see Fig. 3):6.2.1 illumination angle, uithe angle between t
40、he incident-beam axis and the normal (perpendicular) to the surface of thespecimen (the specimen normal).6.2.2 viewing angle for reflection, urangle between the surface normal and the axis of the receiver.6.2.3 viewing angle for transmission, utangle between the axis of the transmitted beam and the
41、axis of the receiver.6.3 aperture anglesthe angles subtended at a point on the specimen by the maximum dimension of the apparent illuminatorand receiver. They are a necessary part of the geometric specification because the finite size of every practical illuminator limitscollimation.6.4 azimuthal an
42、gle, hthe angle between the plane containing the illuminator axis and the specimen normal and the planecontaining the receiver axis and the specimen normal. Unless an azimuthal angle is specified, the illuminator axis, the specimennormal, and the receiver axis are taken to be in the same plane.6.5 r
43、otation angle, the angle indicating the orientation of the test specimen when it is rotated in its own plane. Theorientation of the specimen is considered to be part of the specimen description in this guide (see 10.2.712.2.7).6.6 Complete geometric specifications are necessary for measuring such ge
44、ometrically dependent factors as gloss, transparency,and haze. For ideally specular or ideally regular or diffuse reflection or transmission, specification of only the directions ofillumination and view is usually adequate.7. Measured Quantities7.1 The following quantities, defined and described in
45、more detail in the Illuminating and Viewing Conditions section ofPractice E1164 and in CIE Publication No. 15.2, are those most commonly measured by spectrophotometry and tristimulus (filter)colorimetry for the assessment of color and related appearance attributes.FIG. 3 Designations of Flux, F, and
46、 Angles u, h, for Reflectance and Transmittance MeasurementE179 1247.1.1 45/normal (45/0) and normal/45 (0/45) reflectance factorfor the 45/0 condition, the specimen is illuminated by oneor more beams at an angle of 45 from the specimen normal to the specimen surface. The angle between the direction
47、 of viewingand the specimen normal should not exceed 10. For the 0/45 condition, these requirements are interchanged. Suitable restrictionson the angles of illumination and viewing and on the aperture angles should be observed.7.1.2 total/normal (t/0) or diffuse/normal (d/0) and normal/total (0/t) o
48、r normal/diffuse (0/d) reflectance factorfor the t/0 ord/0 conditions, the specimen is illuminated diffusely, for example by an integrating sphere. The angle between the normal to thespecimen surface and the direction of viewing should not exceed 10. If all specularly reflected light is included in
49、themeasurements, the condition is t/0; if all specularly reflected light is excluded, the condition is d/0. For the 0/t or 0/d conditions,the requirements for illumination and viewing are interchanged. Suitable restrictions on the aperture angles and the nature of theintegrating sphere must be observed.7.1.3 regular transmittance of fully transparent specimensthe specimen is illuminated with an illumination angle notexceeding 5. The requirements for illumination and viewing may be interchanged. Suitable restrictions on the aperture anglesshou
