1、Designation:E230203a(Reapproved 2009)Standard Test Method forMeasurement of the Luminance Coefficient Under DiffuseIllumination of Pavement Marking Materials Using a PortableReflectometer1This standard is issued under the fixed designation E2302;the number immediately following the designation indic
2、ates 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 covers measurement of the luminan
3、cecoefficient under diffuse illumination of horizontal pavementmarkings,such as traffic stripes and surface symbols,andpavement surfaces,in a particular viewing direction using aportable reflectometer.NOTE1The luminance coefficient under diffuse illumination is ameasure of the reflection of horizont
4、al pavement markings and pavementsurfaces in a particular viewing direction in daylight or under roadlighting.Diffuse illumination approximates daylight illumination from theovercast sky,and road lighting as an average of locations on the pavementsurface.1.2 The co-viewing angle of the reflectometer
5、 affects thereadings.As specified by the European Committee for Stan-dardization(CEN),the co-viewing angle shall be 2.29.1.3 This test method is intended to be used for fieldmeasurement of pavement markings and pavement surfaces butmay be used to measure the performance of materials onsample panels
6、before placing the marking material in the field.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 regul
7、atory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E284 Terminology of AppearanceE809 Practice for Measuring Photometric Characteristics ofRetroreflectors2.2 Other Standard:CEN EN 1436 Road Marking MaterialsRoad MarkingPerformance for Road Users33.Terminology3.1 The terminology
8、 used in this test method generallyagrees with that used in Terminology E284.3.2 Definitions:3.2.1 luminance coeffcient under diffuse illumination;Qd,nthe ratio of luminance,L,in a particular viewing direction,of a projected surface to the illuminance of diffuseillumination,E,at the surface on the p
9、lane of the surface,expressed in candelas per square metre per lux(cdm-2lx-1).3.2.1.1 DiscussionQd has a range from zero up to amaximum of 1/=approximately 0.318 cdm-2lx-1.Forconvenience,the units used commonly are millicandelas persquare metre per lux(mcdm-2lx-1)providing a range fromzero up to 100
10、0/=approximately 318 mcdm-2lx-1.3.2.2 co-viewing angle,a,nthe angle between the plane ofthe pavement marking surface and the observation axis.3.2.3 portable reflectometer,na hand-held instrument thatcan be used in the field or laboratory for measurement ofluminance coefficient under diffuse illumina
11、tion.3.2.4 instrument standard,nworking standard used tostandardize the portable reflectometer.4.Summary of Test Method4.1 This test method involves the use of commercial por-table reflectometers for determining the luminance coefficientunder diffuse illumination in a particular viewing direction of
12、horizontal coatings materials used in pavement markings.4.2 The co-viewing angle is fixed at 2.29.4.3 The reflectometers use an external panel or other instru-ment standard of known luminance coefficient under diffuseillumination,Qd.1This test method is under the jurisdiction of ASTM Committee E12 o
13、n Colorand Appearance and is the direct responsibility of Subcommittee E12.10 onRetroreflection.Current edition approved Aug.1,2009.Published September 2009.Originallyapproved in 2003.Last previous edition approved in 2003 as E2302 03a.DOI:10.1520/E2302-03AR09.2For referenced ASTM standards,visit th
14、e 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 European Committee for Standardization(CEN),36 rue deStassart,B-1050,Brussels,Belgium,htt
15、p:/www.cenorm.be.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.4 The portable reflectometer is placed directly over thepavement marking to be measured,ensuring that the measure-ment area of the reflectometer fits within the width of t
16、hestripe,and the reading displayed by the reflectometer isrecorded.4.5 Readings shall be taken for the direction of traffic.Readings shall be taken for each direction of traffic separatelyfor centerlines.5.Significance and Use5.1 The quality of the stripe for visibility in daylight orunder road lighting is determined by the luminance coefficientunder diffuse illumination,Qd,and depends on the materialsused,age,and wear pattern.These conditions shall be observedand noted by the user.5.2 Under the