1、Designation: C1864 17Standard Test Method forDetermination of Solar Reflectance of DirectionallyReflective Material Using Portable Solar Reflectometer1This standard is issued under the fixed designation C1864; the number immediately following the designation indicates the year oforiginal adoption or
2、 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 a technique for determining thesolar reflectance of a d
3、irectionally reflective material using acommercial portable solar reflectometer, including but notlimited to roofing materials with granules or surface design thatresults in angularly dependent reflectance. The purpose of themethod is to evaluate the seasonal and annual solar reflectancesof a direct
4、ionally reflective roofing product.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user
5、 of this standard to establish appro-priate safety, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in th
6、e Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C1549 Test Method for Determination of Solar ReflectanceNear Ambient Temper
7、ature Using a Portable Solar Reflec-tometer3. Terminology3.1 DefinitionsThe definitions included in Test MethodC1549 are applicable to this method.3.2 Definitions of Terms Specific to This Standard:3.2.1 directionally reflective material (DRM), nmaterialwith solar reflectance that varies with solar
8、incidence angle.3.3 Symbols:3.3.1 J,Ksolar reflectance measured by reflectometer inazimuthal orientation J, within measurement series K.3.3.2 Jsolar reflectance measured by reflectometer inazimuthal orientation J, averaged over all measurement repeti-tions.4. Summary of Test Method4.1 This method us
9、es a hemispherical solar reflectometer todetermine the solar reflectance of a DRM. The reflectometer isoperated in accordance with Test Method C1549, except thatevaluation of the surface follows the procedure described in 4.2and 4.3.4.2 The solar reflectance of a test specimen is measured 12times by
10、 rotating the measurement head of the reflectometer in30 increments about the normal to the test specimen.4.3 The set of 12 measurements is repeated three times tocalculate the solar reflectance in each orientation as the averageof the three measurements at the same orientation.5. Significance and U
11、se5.1 The solar reflectance of a DRM depends on the solarincidence angle. This method is intended to provide solarreflectance values for DRM roofing products.6. Apparatus6.1 This test method employs a portable solar reflectometerthat is operated in accordance with Test Method C1549.6.2 The test spec
12、imen shall be flat (not curved) and havearea sufficient to completely cover the measurement port of thereflectometer.6.3 The test specimen shall be placed at the center of acompass pattern marked in 30 increments as shown in Fig. 1.6.4 A vertical indicator arrow, parallel to the central axis ofthe r
13、eflectometer head and affixed to the outer wall of the1This test method is under the jurisdiction ofASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved Sept. 1, 2017. Published September 2017. DOI:10.1520/C186
14、4-17.2For 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
15、Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by
16、 the World Trade Organization Technical Barriers to Trade (TBT) Committee.1reflectometer head, shall be used to gauge the azimuthal angleof the reflectometer head with respect to the compass mark-ings.7. Procedure7.1 Set-Up:7.1.1 Prepare the compass pattern template as shown inAnnex A1 and cut out t
17、he square that identifies the measure-ment area.7.1.2 Affix the compass pattern to the test bench and placethe test specimen on the compass pattern. The compass patternshall not move during the test.7.1.3 Affix a vertical indicator arrow parallel to the centralaxis of the reflectometer head as shown
18、 in Fig. 2.7.1.4 Set up and calibrate the reflectometer in accordancewith Test Method C1549.7.2 Solar Reflectance Measurements:7.2.1 Solar reflectance measurements shall be performed inaccordance with Test Method C1549, at positions specified inthis section.7.2.2 Place the test specimen at the cente
19、r of the compasspattern. The specimen shall not move during the test.7.2.3 Center the reflectometer measurement port over thespecimen such that the compass pattern markings are clearlyvisible as show in Fig. 3.7.2.4 Orient the reflectometer head with the indicator arrowpointing to 0 being the direct
20、ion of maximum reflectance fromthe manufacturer. A diagram of the orientation is shown in Fig.4. The angular deviation of the indicator arrow from 0 shallnot exceed 5.7.2.5 Rest the reflectometer measurement port on the speci-men.7.2.6 Record this value as 1,1.7.2.7 Rotate the reflectometer 30 about
21、 the specimen sur-face normal as shown in Fig. 5, keeping the center of thereflectometer within one cm of its previous position in thehorizontal plane.7.2.8 Rest the reflectometer measurement port on thespecimen, and record solar reflectance measured in this orien-tation as 2,1.7.2.9 Repeat steps 7.
22、2.7 and 7.2.8 for each remaining 30intervals, recording these solar reflectances as 3,112,1.7.2.10 Repeat steps 7.2.7 and 7.2.8 two times, recording theadditional solar reflectance measurement series as 1,212,2and 1,3. 12,3.7.2.11 The average solar reflectance in each orientation J is:J5 J,11 J,21 J
23、3!3 (1)7.2.12 Define RSas the maximum of J12.RW5 J5112J!12 (2)Ra5 Rs1 Rw!2 (3)RSis an estimate of the summer season DSR, RWis anestimate of the winter DSR,3and Rais an estimate of theannual DSR.8. Report8.1 Reporting requirements shall be in accordance with TestMethod C1549 and 8.1.1 8.1.4.8.1.1 A
24、table containing the 36 measured solar reflectancesas shown in Annex A2.8.1.2 The values determined for Rs,Rw, and Ra.8.1.3 A description of the color variation of observationangle (if any).8.1.4 A photograph of the specimen that shows the zeroazimuth direction.3Akbari, H. and Touchaei, A.G., “Model
25、ing and labeling heterogeneous direc-tional reflective roofing materials,” Solar Energy Materials and Solar Cells, Vol.124, 2014, pp. 192210.FIG. 1 Specimen Placed at Center of Compass PatternFIG. 2 Vertical Indicator Arrow Affixed to Side of Portable Reflec-tometerC1864 1729. Precision and Bias9.1
26、PrecisionAn interlaboratory study of this test will beconducted and a complete precision statement is expected to beavailable within three years of the initial approval of thestandard.9.2 BiasNo information can be presented on the bias ofthe procedure in the Test Method for measuring solar reflec-ta
27、nce of a directionally reflective material using a portablesolar reflectometer because no material having an acceptedreference value is available.FIG. 3 Reflectometer Head Placed at Center of SpecimenFIG. 4 Reflectometer Heads Initial Orientation is 0C1864 173ANNEXES(Mandatory Information)A1. DRM CO
28、MPASS PATTERN TEMPLATEA1.1 See Fig. A1.1.FIG. 5 Rotating Reflectometer Head by 30C1864 174A2. EXAMPLE REPORTING TABLE FOR DRM TEST SPECIMEN MEASUREMENTSA2.1 See Table A2.1.FIG. A1.1 DRM Compass Pattern TemplateC1864 175ASTM International takes no position respecting the validity of any patent rights
29、 asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any ti
30、me by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will
31、receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM
32、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or t
33、hrough the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ A2.1 Example Reporting Table for DRM Test SpecimenMeasurementsAngle () Solar Reflectance Measu
34、rements Average Solar Reflectance0Enter measurement0.000Enter measurementEnter measurement30Enter measurement0.000Enter measurementEnter measurement60Enter measurement0.000Enter measurementEnter measurement90Enter measurement0.000Enter measurementEnter measurement120Enter measurement0.000Enter measu
35、rementEnter measurement150Enter measurement0.000Enter measurementEnter measurement180Enter measurement0.000Enter measurementEnter measurement210Enter measurement0.000Enter measurementEnter measurement240Enter measurement0.000Enter measurementEnter measurement270Enter measurement0.000Enter measurementEnter measurement300Enter measurement0.000Enter measurementEnter measurement330Enter measurement0.000Enter measurementEnter measurementSummer Solar Reflectance Rs0.000Winter Solar Reflectance Rw0.000Annual Solar Reflectance Ra0.000C1864 176
