ASTM D1518-1985(2003) Standard Test Method for Thermal Transmittance of Textile Materials《纺织材料的热传导的标准试验方法》.pdf
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1、Designation: D 1518 85 (Reapproved 2003)Standard Test Method forThermal Transmittance of Textile Materials1This standard is issued under the fixed designation D 1518; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the overallthermal transmission coefficients due to the combined action ofco
3、nduction, convection, and radiation for dry specimens oftextile fabrics, battings, and other materials within the limitsspecified in 1.2. It measures the time rate of heat transfer froma warm, dry, constant-temperature, horizontal flat-plate upthrough a layer of the test material to a relatively cal
4、m, coolatmosphere.1.2 For practical purposes, this test method is limited todeterminations on specimens of fabrics, layered fabric assem-blies, and battings having thermal transmittances (U2,asdefined in 3.1.2) within a range of 0.7 to 14 W/m2K andthicknesses not in excess of 50 mm.1.3 The coefficie
5、nts obtained apply strictly only to theparticular specimens tested and for the specified thermal andenvironmental conditions of each test. This test method givesvalues that are valid for comparison under the same conditionsof test, that is, with the specified air velocity, temperaturedifference betw
6、een the warm plate and the cool air, and air gapfor measuring cool air temperature.1.4 The values stated in metric units are to be regarded asthe standard. Conversion factors, for thermal conductance andconductivity and thermal resistance and resistivity, to otherunits in common use are given in Tab
7、les 1-51.5 This standard does not purport to address the safetyconcerns associated with its use. It is the responsibility ofwhoever uses this standard to consult and establish appropri-ate safety and health practices and determine the applicabilityof regulatory limitations prior to use.2. Referenced
8、 Documents2.1 ASTM Standards:D 123 Terminology Relating to Textiles2D 1777 Method for Measuring Thickness of Textile Mate-rials23. Terminology3.1 Definitions:3.1.1 bulk density, napparent mass per unit volume.3.1.1.1 DiscussionIn testing the thermal transmittance offabrics, bulk density is calculate
9、d from the fabric weight perunit area and the thickness value used to calculate thermalconductivity.3.1.2 clo, nunit of thermal resistance defined as theinsulation required to keep a resting man (producing heat at therate of 58 W/m2) comfortable in an environment at 21C, airmovement 0.1 m/s, or roug
10、hly the insulation value of typicalindoor clothing.3,4(Syn. intrinsic clo).3.1.2.1 DiscussionNumerically the clo is equal to 0.155Km2/W.3.1.3 heat transfer coeffcient, nsee thermal transmit-tance.3.1.4 intrinsic clo, nsee clo.3.1.5 specific clo, nthe specific thermal resistance in clounits per unit
11、thickness.3.1.6 thermal conductance, nsee thermal transmittance.3.1.7 thermal conductivity, ntime rate of unidirectionalheat transfer per unit area, in the steady-state, between parallelplanes separated by unit distance, per unit difference oftemperature of the planes.3.1.7.1 DiscussionNumerically,
12、thermal conductivityequals the product of the heat transfer coefficient and thedistance separating the planes. Thus, k, the thermal conductiv-ity of the fabric only, is the product of U2and the fabricthickness. Units of thermal conductivity are W/mK.3.1.8 thermal resistance, nreciprocal of thermal t
13、ransmit-tance.3.1.9 thermal resistivity, nreciprocal of thermal conduc-tivity.3.1.10 thermal transmittance, ntime rate of unidirectionalheat transfer per unit area, in the steady-state, between parallelplanes, per unit difference of temperature of the planes (Syn.thermal conductance, heat transfer c
14、oefficient).1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.51 on Chemical Conditioningand Performance.Current edition approved July 26, 1985. Published September 1985. Originallypublished as D 1518 57 T. Last previous
15、 edition D 1518 77.2Annual Book of ASTM Standards, Vol 07.01.3American Society of Heating, Refrigerating, and Air-Conditioning Engineers.4Gagge, A. P., Burton, A. C., Bazett, H. C., Science, Vol 94, Nov. 7, 1941, pp.428430.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
16、ohocken, PA 19428-2959, United States.3.1.10.1 DiscussionThermal transmittance is expressed aswatts per square metre of test specimen per kelvin differencebetween the hot plate and the cool atmosphere (W/m2K).Thermal transmittance for three different cases is deter-mined in this method:U1= combined
17、thermal transmittance of the test specimenand air.Ubp= thermal transmittance of the plate without fabriccover (“bare plate”). This property reflects the in-strument constant and is used to standardize theplate, and, in conjunction with U1, is used in thecalculation of U2.U2= thermal transmittance of
18、 fabric only. This valuecorresponds to the C value (W/m2K) defined andused by ASTM and ASHRAE.4In the calculation ofthis value the assumption is made that the boundarylayers of the bare plate and the boundary layers ofthe fabric are equal. Experimental results indicatethat the U2values are valid whe
19、n tested within thelimits specified in Section 1.3.1.11 total clo, nthe intrinsic clo plus the thermal resis-tance from the air boundary.3.1.12 For definitions of other textile terms used in thismethod, refer to Terminology D 123.3.2 Definitions of Terms Specific to This Standard:3.2.1 effective ins
20、ulation ratio, nindicates the increase ininsulation afforded by the fabric in comparison to the uncov-ered test plate under specified conditions of test.3.2.2 mean temperature, nthe average of the hot platetemperature and the temperature of the calm, cool air thatprevailed during the test.4. Signifi
21、cance and Use4.1 The thermal transmittance of a fabric or batting is ofconsiderable importance in determining its suitability for use infabricating cold weather protective gear and clothing. Thethermal interchange between man and his environment is,however, an extremely complicated subject which inv
22、olvesmany factors in addition to the equilibrium insulation values offabrics and battings. Therefore, measured thermal transmit-tance coefficients can only indicate relative merit of a particularmaterial.4.2 The measurement of heat transfer coefficients is a verydifficult and highly technical field,
23、 and it is not practical in aTABLE 1 Conversion Factors for Thermal ConductivityATo ConvertThermal Con-ductivityMultiply byFromtoW/mKBWcm/m2K W/cmK cal/scmK kg-cal/hmKkg-calcm/hm2KBtu/hftFBtuin/hft2Fin/clo mm/cloW/mK 1. 1. 3 10+21. 3 1022.388 3 1038.598 3 1018.598 3 10+15.778 3 1016.934 6.093 1.548
24、3 10+2Wcm/m2K1. 3 1021. 1. 3 1042.388 3 1058.598 3 1038.598 3 1015.778 3 1036.934 3 1026.093 3 1021.548W/cmK 1. 3 10+21. 3 10+41. 2.388 3 1018.598 3 10+18.598 3 10+35.778 3 10+16.934 3 10+26.093 3 10+21.548 3 10+4cal/scmK 4.187 3 10+24.187 3 10+44.187 1. 3.6 3 10+23.6 3 10+42.419 3 10+22.903 3 10+32
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