ASTM_E_2539_-_14.pdf

Designation:E253914Standard Test Method forMultiangle Color Measurement of Interference Pigments1This standard is issued under the fixed designation E2539;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.INTRODUCTIONObjects that exhibit a change in color with different angles of illumination and view are said to be“gonioapparent.”The tristimulus colorimetric values of gonioapparent objects are derived using thespectral reflectance factors obtained from spectrometric measurements or colorimetric measurementsat various angles of illumination and detection.The tristimulus colorimetric values are computed usingthe spectral reflectance factors of the object,the CIE Standard Observer,and the spectral powerdistribution of the illuminant,as described in Practice E308.This Test Method,E2539,specifies thecolor measurement of interference pigments at various illumination and detection angles.1.Scope1.1 This test method covers the instrumental requirementsand required parameters needed to make instrumental colormeasurements of thin film interference pigments.This testmethod is designed to encompass interference pigments used inarchitectural applications,automobiles,coatings,cosmetics,inks,packaging,paints,plastics,printing,security,and otherapplications.1.2 Characterization of the optical behavior of materialscolored with interference pigments requires measurement atmultiple angles of illumination and detection.1.3 Data taken utilizing this test method are quantitative andare appropriate for quality control of interference pigmentcolor.1.4 The measurement results are usually expressed as re-flectance factors,tristimulus color values,or as CIE L*a*b*color coordinates and color difference.1.5 The totality of data taken may not be necessary forevaluating mixtures also containing non-interference pigments.The committee is investigating and evaluating the appropriate-ness of this test method for those materials.It is the responsi-bility of the users to determine the applicability of this testmethod for their specific applications.1.6 Interference pigments are typically evaluated for colorand color appearance in a medium,such as paint or ink.Thegonioapparent effect depends strongly on the physical andchemical properties of the medium.Some of the propertiesaffecting color and color appearance include vehicle viscosity,thickness,transparency,and volume solids.As a general rule,for quality control purposes,interference pigments are bestevaluated in a masstone product form.In some cases thisproduct form may be the final product form,or more typicallya qualified simulation of the intended product form(such as apaint drawdown)that in terms of color and appearancecorrelates to final product application.1.7 This standard does not address the requirements forcharacterizing materials containing metal flake pigments.Mea-surements of the optical characteristics of materials containingmetal flake pigments are described in Test Method E2194.1.8 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.9 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:2E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE805 Practice for Identification of Instrumental Methods of1This test method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.12 onGonioapparent Color.Current edition approved Nov.1,2014.Published November 2014.Originallyapproved in 2008.Last previous edition approved in 2012 as E2539 12.DOI:10.1520/E2539-14.2For 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 Color or Color-Difference Measurement of MaterialsE1164 Practice for Obtaining Spectrometric Data for Object-Color EvaluationE1345 Practice for Reducing the Effect of Variability ofColor Measurement by Use of Multiple MeasurementsE1708 Practice for Electronic Interchange of Color andAppearance DataE1767 Practice for Specifying the Geometries of Observa-tion and Measurement to Characterize the Appearance ofMaterialsE2194 Test Method for Multiangle Color Measurement ofMetal Flake Pigmented MaterialsE2480 Practi