ASTM_D_4061_-_13.pdf

Designation:D406113Standard Test Method forRetroreflectance of Horizontal Coatings1This standard is issued under the fixed designation D4061;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 retroreflective properties of horizontal surfacingmaterials,such as traffic stripe paint systems,traffic tapes,andtraffic surface symbols.1.2 Specimen preparation,size,and shape must be deter-mined and specified by the user of this test method.Likewise,the user must specify the observation and entrance angles to beused(see Fig.1).1.3 The geometric requirements of this test method arebased on materials for which the relative retroreflectancechanges less than approximately 50%over the observationangle range from 0.2 to 0.5.This is illustrated in Fig.2.1.4 This test method is a laboratory test and requires afacility that can be darkened sufficiently so that stray light doesnot affect the test results.This facility must be capable ofhousing the required 15-m test distance.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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 SystemE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE808 Practice for Describing RetroreflectionE809 Practice for Measuring Photometric Characteristics ofRetroreflectors2.2 CIE Publication:3No.54 Retroreflection Definition and Measurement3.Terminology3.1 The terms and definitions in Terminology E284 apply tothis test method.3.2 Definitions:3.2.1 coeffcient of retroreflected luminance,RL,nratio ofthe luminance,L,of a projected surface to the normalilluminance,E,at the surface on a plane normal to theincident light,expressed in candelas per square metre per lux(cdm2lx1).RL5L/E!(1)3.2.2 datum mark,nin retroreflection,an indication on theretroreflector that is used to define the orientation of theretroreflector with respect to rotation about the retroreflectoraxis.3.2.2.1 DiscussionThe datum mark must not lie on theretroreflector axis.3.2.3 entrance angle,nin retroreflection,angle betweenthe illumination axis and the retroreflector axis.3.2.3.1 DiscussionFor plane retroreflective surfaces,theentrance angle is no larger than 90.3.2.3.2 DiscussionThe entrance angle may be divided intocomponents 1and 2.This is described in Practice E808.Inthis test method only the component 1is used.Therefore,where only the entrance angle is specified the conventionused is 2=0 and 1=.3.2.4 illumination axis,nin retroreflection,a line from theeffective center of the source aperture to the retroreflectorcenter.3.2.5 normal illuminance,Ethe illuminance on a retrore-flective surface measured in the plane that passes through the1This test method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.10 onRetroreflection.Current edition approved July 1,2013.Published August 2013.Originallyapproved in 1989.Last previous edition approved in 2006 as D4061 94(2006).DOI:10.1520/D4061-13.2For 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.3Available from U.S.National Committee of the CIE(International Commissionon Illumination),C/o Thomas M.Lemons,TLA-Lighting Consultants,Inc.,7 PondSt.,Salem,MA 01970,http:/www.cie-usnc.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 retroreflector center and is perpendicular to the illuminationaxis;measured in lux(lumensm2).3.2.6 observation angle,nangle between the axes of theincident beam and the observed(reflected)beam,(inretroreflection,between the illumination axis and the obser-vation axis).3.2.6.1 DiscussionThe observation angle is always posi-tive and in the context of retroreflection is restricted to smallacute angles.3.2.7 observation axis,nin retroreflection,a line from theeffective center of the receiver aperture to the retroreflectorcenter.3.2.8 receiver,nthe portion of a photometric instrumentthat receives the viewing beam from the specimen,including acollector such as an integrating sphere,if used,often themonochromator or spectral filter