1、Designation: E1710 11E1710 18Standard Test Method forMeasurement of Retroreflective Pavement Marking Materialswith CEN-Prescribed Geometry Using a PortableRetroreflectometer1This standard is issued under the fixed designation E1710; the number immediately following the designation indicates the year
2、 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 retroreflecti
3、ve properties of horizontal pavement marking materials containingretroreflecting beads, such as traffic stripes and surface symbols, using a portable retroreflectometer that can be placed on the roaddelineation to measure the retroreflection at a prescribed geometry.NOTE 1The restriction to bead bas
4、ed materials is for the purpose of ensuring a sufficiently gradual optical response function (from points of the sourceaperture to points of the receiver aperture) to allow generous sized instrument source and receiver apertures.1.2 The entrance and observation angles of the retroreflectometer affec
5、t the readings. As specified by the European Committeefor Standardization (CEN), the entrance and observation angles shall be 88.76 and 1.05, respectively.1.3 This test method is intended to be used for field measurement of pavement markings but may be used to measure theperformance of materials on
6、sample panels before placing the marking material in the field.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental pract
7、ices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Rec
8、ommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D4061 Test Method for Retroreflectance of Horizontal CoatingsD6359 Specification for Minimum Retroreflectance of Newly Applied Pavement Marking Using Portable Han
9、d-OperatedInstruments (Withdrawn 2006)3E177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE284 Terminology of AppearanceE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE809 Practice for Measuring Photometric Characteristics of R
10、etroreflectors2.2 Other Standard:CEN EN 1436 Road Marking MaterialsRoad Marking Performance for Road Users43. Terminology3.1 The terminology used in this test method generally agrees with that used in Terminology E284.3.2 DefinitionsThe delimiting phrase “in retroreflection” applies to each of the f
11、ollowing definitions when used outside thecontext of this or other retroreflection test methods:1 This test method is under the jurisdiction ofASTM Committee E12 on Color andAppearance and is the direct responsibility of Subcommittee E12.10 on Retroreflection.Current edition approved June 1, 2011Jan
12、. 1, 2018. Published June 1, 2011February 2018. Originally approved in 1995. Last previous edition approved in 20052011 asE1710 05.E1710 11. DOI: 10.1520/E171011.10.1520/E171018.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. F
13、or Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.4 Available from European Committee for Standardization (CEN), 36 rue de Stassart, B-1050, Brusse
14、ls, Belgium, http:/www.cenorm.be.This 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 accurately, ASTM recomm
15、ends 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 States13.2.1 coeffcien
16、t of retroreflected luminance, RL, nthe ratio of the luminance, L, of a projected surface to the normalilluminance, E, at the surface on a plane normal to the incident light, expressed in candelas per square metre per lux (cdm2lx1).3.2.1.1 DiscussionBecause of the low luminance of pavement markings,
17、 the units used commonly are millicandelas per square metre per lux(mcdm2lx1).3.2.2 co-entrance angle, C, nthe complement of the entrance angle (90 ).3.2.3 co-viewing angle, C, nthe complement of the viewing angle (90 ).3.2.4 entrance angle, , nthe angle between the illumination axis and the retrore
18、flector axis.3.2.5 observation angle, , nthe angle between the illumination axis and the observation axis.3.2.6 portable retroreflectometer, na hand-held instrument that can be used in the field or laboratory for measurement ofretroreflectance.3.2.6.1 DiscussionIn this test method, “portable retrore
19、flectometer” refers to a hand-held instrument that can be placed over roadway delineation tomeasure the coefficient of retroreflected luminance with a prescribed geometry.3.2.7 presentation angle, , nthe angle between the observation half-plane and the half-plane that originates on theillumination a
20、xis and that contains the retroreflector axis.3.2.8 instrument standard, nworking standard used to standardize the portable retroreflectometer.3.2.9 retroreflection, na reflection in which the reflected rays are returned preferentially in directions close to the opposite ofthe direction of the incid
21、ent rays, this property being maintained over wide variations of the direction of the incident rays.3.2.10 viewing angle, nthe angle between the retroreflector axis and the observation axis.3.2.10.1 DiscussionThe retroreflector axis for pavement markings is normal to the marking.4. Summary of Test M
22、ethod4.1 This test method involves the use of commercial portable retroreflectometers for determining the coefficient of retroreflectedluminance of horizontal coating materials used in pavement markings.4.2 The entrance angle is fixed at 88.76 (co-entrance angle 1.24).4.3 The observation angle is fi
23、xed at 1.05.4.4 The presentation angle shall be 0.4.5 The portable retroreflectometers use either a built-in reference white for standardization or use an external panel of knowncoefficient of retroreflected luminance, or both.4.6 The retroreflectometer is placed directly over the pavement marking t
24、o be measured, ensuring that the measurement areaof the retroreflectometer fits within the width of the stripe, and the reading displayed by the retroreflectometer is recorded.4.7 The retroreflectometer is then moved to other positions on the pavement marking, and the readings are recorded andaverag
25、ed.4.8 Readings shall be taken and averaged in each direction of traffic for a centerline.5. Significance and Use5.1 The quality of the stripe is determined by the coefficient of retroreflected luminance, RL, and depends on the materials used,age, and wear pattern. These conditions shall be observed
26、 and noted by the user.5.2 Under the same conditions of illumination and viewing, larger values of RL correspond to higher levels of visualperformance.5.3 Retroreflectivity of pavement (road) markings degrade with traffic wear and require periodic measurement to ensure thatsufficient line visibility
27、 is provided to drivers.5.4 For a given viewing distance, measurements of RL made with a retroreflectometer having a geometry corresponding to thatviewing distance are a good indicator of the visual ranking of material measured.E1710 1825.5 As specified by CEN, the measurement geometry of the instru
28、ment is based on a viewing distance of 30 m, a headlightmounting height of 0.65 m directly over the stripe, and an eye height of 1.2 m directly over the stripe.5.6 It shall be the responsibility of the user to employ an instrument having the specified observation and entrance angles.6. Apparatus6.1
29、Portable Retroreflectometer:6.1.1 The retroreflectometer shall be portable, with the capability of being placed on various horizontal pavement markings indifferent locations.6.1.2 The retroreflectometer shall be constructed so that placement on the highway pavement markings will preclude any strayli
30、ght from entering the measurement area of the instrument and affecting the reading.6.1.3 For the convenience of the user, a marking shall be placed on the instrument to permit it to be aligned with the directionof traffic.6.2 Light Source Requirements:6.2.1 The projection optics shall be such that t
31、he distribution of the illuminance over the measurement area will be within 10 %of the average illuminance.6.2.2 The aperture angle of the light source as determined from the center of the measurement area shall not be larger than arectangle subtending 10 min of arc (0.17) by 20 min of arc (0.33).6.
32、2.2.1 Rectangle aperture dimensions are given with the first side parallel to the observation half plane.NOTE 2The maximum source aperture dimensions are in agreement with CEN EN 1436. There is experimental evidence that for this test method,using this maximum source aperture together with the maxim
33、um receiver aperture in 6.3.3 produces RL measurements within 1.5 % of those using two10-min circular apertures as specified in Test Method D4061.6.3 Receiver Requirements:6.3.1 The receiver shall have sufficient sensitivity and range to accommodate coefficient of retroreflected luminance valuesexpe
34、cted in use, typically 1 to 2000 mcdm2lx1.6.3.2 The combined spectral distribution of the light source and the spectral responsivity of the receiver shall match thecombined spectral distribution of CIE Standard Illuminant A and the V() spectral luminous efficacy function. The match shallensure corre
35、ct measurement of at least white and yellow pavement marking materials according to the following criterion:6.3.2.1 Awhite (spectrally neutral) reflection standard and two plano parallel long pass absorption filters with pass wavelengthsat respectively approximately 515 nm and 550 nm, providing colo
36、rs of yellow and amber, are used.6.3.2.2 The white reflection standard is measured. An absorption filter is inserted in front of the white reflection standard, sothat illumination and measurement takes place through the filter, and a new measurement is made. The filter shall be mounted witha small t
37、ilt to avoid signal by surface reflection, and at some distance from the standard to avoid surface reflection back to thestandard. See Fig. 1.6.3.2.3 The ratio of the RL measured with a filter to the RL measured without the filter shall be within 5 % of the IlluminantA luminous transmittance of an a
38、ir-spaced pair of two such filters.6.3.2.4 Filters of colors other than described above may be used to demonstrate the ability of a retroreflectometer to measurepavement marking materials of such colors. A long pass absorption filter with a pass wavelength at approximately 715 nmcorresponding to inf
39、rared may also be used. The RL with the infrared filter inserted is theoretically zero, but a measured RL upto 5 % of the RL of the white standard may be acceptable.6.3.3 The aperture of the receiver as determined from the center of the measurement area shall not be larger than a square circlewith a
40、 diameter subtending 20 min of arc (0.33) by 20 min of arc (0.33).NOTE 3The maximum receiver aperture dimensions are in agreement with CEN EN 1436. There is experimental evidence that for this test method,using this maximum receiver aperture together with the maximum source aperture in 6.2.2 produce
41、s RL measurements within 1.5 % of those using two10-min circular apertures as specified in Test Method D4061.6.3.4 Instruments with annular apertures are not recommended for measuring pavement markings.6.3.5 The combined stability of the output of the light source and receiver shall be such that rea
42、dings will not change more than61 % after 10 s when the retroreflectometer is in contact with the pavement marking and ready to measure.FIG. 1 White Reflection Standard and Absorption Filter for Testing Spectral MatchE1710 1836.3.6 The linearity of the retroreflectometer photometric scale over the r
43、ange of readings expected shall be within 2 %.Correction factors may be used to ensure a linear response. A method for determining linearity is found in Annex A2, Method forDetermining Photoreceptor Linearity, of Practice E809.6.4 Measurement Geometry:6.4.1 The light source and receiver may be eithe
44、r at optical infinity or at a finite distance from the measurement area, and theyshall be separated from each other by a distance corresponding to an observation angle of 1.05 6 0.02.6.4.2 The entrance angle of the retroreflectometer shall be 88.76 6 0.02 with respect to the entrance aperture plane.
45、6.4.3 The presentation angle of the retroreflectometer shall be 0 and shall be stated in the instrument specifications.6.4.4 See Fig. 2 for a diagram of the optics geometry.6.4.5 The length of the detected area shall either be fully included within the length of the illuminated area (called “arrange
46、mentA”) or the length of the illuminated area shall be fully included within the length of the detected area (called arrangement“ar-rangement B”).NOTE 4Arrangement B is advantageous to arrangement A in the sense that it leads to less variation of the measured RL value with small tilts of theretroref
47、lectometer that are unavoidable in practical field measurements.6.4.6 The smaller of the two areas, detected or illuminated area, is the measurement area and shall be at least 50 cm2. See Fig.3 for a method of testing this area.FIG. 2a Angles and apertures for non-collimating portableretroreflectome
48、terFIG. 2b Angles and apertures for collimating optics portableretroreflectometerFIG. 2c Angles and apertures for portable retroreflectometerwith collimating and beam splitter designFIG. 2 Optics Geometry Diagram for Portable Road Marking Reflectometer: a) Angles and Apertures for Non-Collimating Po
49、rtable Re-flectometer; b) Angles and Apertures for Collimating Optics Portable Reflectometer; c) Angles and Apertures for Portable Reflectome-ter with Collimating and Beam Splitter DesignE1710 184NOTE 5The plate mentioned in Fig. 3 needs in most cases to be a glass plate with a diffuse upper surface, so that the area can be studied from theunderside.6.4.7 Retroreflectometers can be characterized as “fixed-aim instruments” or “aiming instruments.” A fixed-aim instrument hasno facility for adjustment of its tilt
