ASTM_E_1331_-_15.pdf

Designation:E133115Standard Test Method forReflectance Factor and Color by Spectrophotometry UsingHemispherical Geometry1This standard is issued under the fixed designation E1331;the number immediately following the designation indicates the year 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.1.Scope1.1 This test method describes the instrumental measure-ment of the reflection properties and color of object-colorspecimens by the use of a spectrophotometer or spectrocolo-rimeter with a hemispherical optical measuring system,such asan integrating sphere.1.2 The test method is suitable for use with most object-color specimens.However,it should not be used for retrore-flective specimens or for fluorescent specimens when highestaccuracy is desired.Specimens having intermediate-gloss sur-faces should preferably not be measured by use of thisgeometry.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesE179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Transmission Propertiesof MaterialsE284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE805 Practice for Identification of Instrumental Methods ofColor or Color-Difference Measurement of MaterialsE991 Practice for Color Measurement of Fluorescent Speci-mens Using the One-Monochromator MethodE1164 Practice for Obtaining Spectrometric Data for Object-Color EvaluationE1345 Practice for Reducing the Effect of Variability ofColor Measurement by Use of Multiple Measurements3.Terminology3.1 Definitions:3.1.1 The definitions in Guide E179,Terminology E284,and Practice E1164 are applicable to this test method.4.Summary of Test Method4.1 This test method provides a procedure for measuring thereflectance factors of reflecting object-color specimens byusing a spectrophotometer or spectrocolorimeter equipped witha hemispherical optical measuring system such as an integrat-ing sphere.4.2 This test method includes procedures for calibrating theinstrument and for selecting specimens suitable for precisionmeasurement.4.3 Most modern spectrophotometers have the capacity tocompute the color coordinates of the specimen immediatelyfollowing the measurement.When this is the case,the usermust select the color system,observer,and illuminant(seePractice E308,Procedure).5.Significance and Use5.1 The most direct and accessible methods for obtainingthe color coordinates of object colors are by instrumentalmeasurement using spectrophotometers or colorimeters witheither hemispherical or bidirectional optical measuring sys-tems.This test method provides procedures for such measure-ment by reflectance spectrophotometry using a hemisphericaloptical measuring system.5.2 This test method is especially suitable for measurementof the following types of specimens for the indicated uses(Guide E179 and Practice E805):5.2.1 All types of object-color specimens to obtain data foruse in computer colorant formulation.1This test method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.02 onSpectrophotometry and Colorimetry.Current edition approved July 1,2015.Published July 2015.Originally approvedin 1990.Last previous edition approved in 2009 as E1331 09.DOI:10.1520/E1331-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2.2 Object-color specimens for color assessment.5.2.2.1 For the measurement of plane-surface high-glossspecimens,the specular component should generally be ex-cluded during the measurement.5.2.2.2 For the measurement of plane-surface intermediate-gloss specimens and of textured-surface specimens,includingtextiles,where the first-surface reflection component may bedistributed over a wide range of angles,measurement may bemade with the specular component included,but the resultingcolor coordinates may not correlate best with visual judgmentsof the color.The use of bidirectional geometry,such as 45/0 or0/45,may lead to better correlations.5.2.2.3 For the measurement of plane-