1、Designation: D1494 12 An American National StandardStandard Test Method forDiffuse Light Transmission Factor of Reinforced PlasticsPanels1This standard is issued under the fixed designation D1494; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test
3、method covers the determination of the diffuselight transmission factor of translucent reinforced plasticsbuilding panels.1.2 The values stated in SI units are to be regarded as thestandard. The values given in the parentheses are for informa-tion only.1.3 The text of this standard references notes
4、and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in Tables and Figures) shall not be consideredas requirements of this standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
5、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.NOTE 1There is no know ISO equivalent to this standard2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for Test
6、ingD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 ASTM Adjuncts:Test Cabinet for Diffuse Light Transmission Factor ofReinforced Panels33. Terminology3
7、.1 Definitions:GeneralDefinitions are in accordance withTerminology D883 and abbreviations with TerminologyD1600, unless otherwise indicated.4. Significance and Use4.1 The purpose of this test method is to obtain the diffuselight transmittance factor of both flat and corrugated translu-cent building
8、 panels by the use of simple apparatus and byemploying as a light source a combination of fluorescent tubeswhose energy distribution closely approximates CIE Source C.5. Apparatus5.1 The apparatus for this test method shall consist of atransmissometer, Fig. 1, comprising essentially the following:5.
9、1.1 Light SourceThe illumination shall consist of twelve20-W fluorescent tubes which are assembled in three banks offour tubes each, according to the following schedule: daylight,deluxe cool white, blue, and daylight.5.1.2 PhotometerThe photometer shall consist of a pho-tocell and of a galvanometer.
10、 The photocell shall be of thebarrier-layer type and shall contain a visual correction filter.The assembly preferably should be hermetically sealed intoplastic as a protection against moisture. The indicating galva-nometer should contain one scale graduated from 0 to 100, anda circuit with sufficien
11、t variable resistance so that the sensitiv-ity of the photometer can be adjusted over the range of 50 to100 footcandles.5.1.3 Test Cabinet, constructed in accordance with thefollowing dimensions.31This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsib
12、ility of Subcommittee D20.24 on Plastic BuildingProducts.Current edition approved Oct. 1, 2012. Published November 2012. Originallyapproved in 1957. Last previous edition approved in 2008 as D1494 97 (2008)1.DOI: 10.1520/D1494-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
13、orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Detailed working drawings and a bill of materials for this equipment can beobtained at a nominal charge from ASTM Headquarters, 10
14、0 Barr Harbor Drive, POBox C700, West Conshohocken, PA 194282959. Order Adjunct: ADJD1494.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.3.1 The transmitted area of
15、 the test specimen shall be610.0 6 1.6 mm by 610.0 6 1.6 mm (24 6116 in. by 24 6116 in.).5.1.3.2 The distance from the bottom of the fluorescenttubes to the bottom of the test specimen shall be 203.0 6 0.8mm (8 6132 in.).5.1.3.3 A 4.8-mm (316-in.) thick, white, standard outdoor,translucent diffusing
16、 plate shall be placed between the lightsource and the test specimen so that the distance from thebottom of the diffusing plate to the bottom of the test specimenis 31.8 6 0.8 mm (114 6132 in.).5.1.3.4 The photocell shall be positioned below the centeraxis of the test specimen so that the distance f
17、rom the bottomof the specimen to the top of the cell is 283.0 6 0.8 mm (11186132 in.).5.1.3.5 A masking plate containing a 31.8-mm (114-in.)diameter hole in its center shall be placed between the testspecimen and the photocell so that the distance from thebottom of the test specimen to the bottom of
18、 the masking plateshall be 233.0 6 0.8 mm (934 6132 in.).6. Standardization of Transmissometer6.1 Center the photocell beneath the 31.8-mm (114-in.)diameter hole in the bottom masking plate. Place the galva-nometer in a flat level position. Ensure that no current flows inthe electrical circuit by op
19、ening the circuit. Adjust the positionof the indicating needle on the galvanometer to read “0 bymeans of the zero adjustment knob. Close the galvanometercircuit. Turn on the illumination in the transmissometer. Wait aminimum of 20 min to permit the transmissometer to reachequilibrium conditions. Adj
20、ust the galvanometer to read“100. The instrument is now ready to be used for measure-ments of diffuse light transmission factor.Metric Equivalentsin. mm in. mm in. mm in. mm132 0.834 19.1 834 222 2434 634316 4.8 114 31.8 934 248 2512 648737 5.6 112 38.1 12 305 28 71114 6.4 2 50.8 14 356 2912 749932
21、7.1 634 172 24 610 3812 97838 9.5FIG. 1 Assembly Drawing of TransmissometerD1494 1227. Test Specimens7.1 The test specimens shall consist of translucent rein-forced plastic panels having a minimum length of 610 mm (24in.) and a width greater than 610 mm (24 in.), but notexceeding 711 mm (28 in.).8.
22、Conditioning8.1 ConditioningCondition the test specimens at 23 62C (73 6 4F) and 50 6 10 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D618, for those test methods where conditioning isrequired. In cases of disagreement, the tolerances shall be61C
23、(62F) and 62 % relative humidity.8.2 Test ConditionsConduct tests in the Standard Labora-tory Atmosphere of 23 6 2C (73 6 4C) and 50 6 10 %relative humidity, unless otherwise specified in the test meth-ods or in this specification. In cases of disagreement, thetolerances shall be 61C (62F) and 62 %
24、relative humidity.9. Procedure9.1 In making a measurement, place the test specimen in thetest cabinet so that it completely covers the 610 by 610-mm (24by 24-in.) space. The transmittance is read on the galvanometerin percent.10. Report10.1 The report shall include the following:10.1.1 The source an
25、d identity of test specimens.10.1.2 The percent transmission of the test specimen.10.1.3 The average thickness of the test specimen in inchesexpressed to the nearest 0.025 mm (0.001 in.) and comprisingat least ten individual measurements.11. Precision and Bias411.1 Table 1 is based on a round robin
26、conducted in 1987 inaccordance with Practice E691, involving five materials testedby seven laboratories. Because of the nonuniform nature oflarge corrugated sheets, the five samples were sequentially sentto the seven participating laboratories. Each test result is anindividual determination. Each la
27、boratory obtained three testresults for each material.NOTE 2The explanation of Ir and IR (11.2 through 11.2.3) are onlyintended to present a meaningful way of considering the approximateprecision of this test method. The data in Table 1 should not be vigorouslyapplied to acceptance or rejection of m
28、aterials as these data specific to theround robin and may not be representative of other lots, conditions,materials, or laboratories.11.1.1 Users of this test method should apply the principlesoutlined in Practice E691 to generate data specific to theirlaboratory and materials or between specific la
29、boratories. Theprinciples of 11.2 through 11.2.3 then would be valid for suchdata.11.2 Concept of Ir and IRIf Sr and SR have beencalculated from a large enough body of data, and for testresults that are the individual result from testing one specimen:11.2.1 Ir: Repeatability (comparing two test resu
30、lts for thesame material, obtained by the same operator using the sameequipment on the same day)the two test results should bejudged not equivalent if they differ by more than the Ir valuefor that material.11.2.2 IR: Reproducibility (Comparing two test results forthe same material, obtained by diffe
31、rent operators using differ-ent equipment on different days)the two test results shouldbe judged not equivalent if they differ by more than the IRvalue for that material.11.2.3 Any judgment per 11.2.1 and 11.2.2 would have anapproximate 95 % (0.95) probability of being correct.11.3 Bias is systemati
32、c error which contributes to thedifference between a test result and a true (or reference) value.There are no recognized standards on which to base an estimateof bias for this test method.12. Keywords12.1 building panels; diffuse light transmission factor; rein-forced plastics4Supporting data are av
33、ailable from ASTM Headquarters. Request RR:D20 1145.TABLE 1 Precision Values in the Units of PercentMaterial Average SrASRBIrCIRDSample #4 6.1 0.36 1.08 1.02 3.06Sample #5 24.1 0.59 2.48 1.67 7.02Sample #1 59.7 0.45 5.01 1.27 14.18Sample #3 73.0 0.76 3.19 2.16 9.03Sample #2 95.6 0.64 1.61 1.81 4.56A
34、Sr is the within-laboratory standard deviation of the average.BSR is the between-laboratory standard deviation of the average.CIr = 2.83 Sr; andDIR = 2.83 SR.D1494 123SUMMARY OF CHANGESCommittee D20 has identified the location of the following changes to this standard since the last issue(D1494-97(2
35、008)1) that may impact the use of this standard.(1) Removed D4968 reference in Section 2.(2) Removed C618 reference from Section 2.(3) Added D618 reference in Section 2.(4) Updated section 8.1 per D618-08.(5) Updated section 8.2 per D618-08.Committee D20 has identified the location of the following
36、changes to this standard since the last issue(D1494-97(2000)1) that may impact the use of this standard.(1) Reworded ISO equivalency statement per Guide D4968. (2) Adjusted significant digits in 5.1.3.1, 5.1.3.2, 5.1.3.4 and5.1.3.5.ASTM International takes no position respecting the validity of any
37、patent rights 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 revis
38、ion at any time 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 c
39、omments will 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 copyrig
40、hted by ASTM 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 through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D1494 124
