ASTM E1530-2011 Standard Test Method for Evaluating the Resistance to Thermal Transmission of Materials by the Guarded Heat Flow Meter Technique《保护热流计方法材料热传递阻力测定的标准试验方法》.pdf

《ASTM E1530-2011 Standard Test Method for Evaluating the Resistance to Thermal Transmission of Materials by the Guarded Heat Flow Meter Technique《保护热流计方法材料热传递阻力测定的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM E1530-2011 Standard Test Method for Evaluating the Resistance to Thermal Transmission of Materials by the Guarded Heat Flow Meter Technique《保护热流计方法材料热传递阻力测定的标准试验方法》.pdf（9页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: E1530 11Standard Test Method forEvaluating the Resistance to Thermal Transmission ofMaterials by the Guarded Heat Flow Meter Technique1This standard is issued under the fixed designation E1530; the number immediately following the designation indicates the year oforiginal adoption or, i

2、n 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 steady-state technique for thedetermination of the resis

3、tance to thermal transmission (ther-mal resistance) of materials of thicknesses less than 25 mm.For homogeneous opaque solid specimens of a representativethickness, thermal conductivity can be determined (see Note1). This test method is useful for specimens having a thermalresistance in the range fr

4、om 10 to 400 3 10-4m2KW-1, whichcan be obtained from materials of thermal conductivity in theapproximate range from 0.1 to 30 Wm-1K-1over the approxi-mate temperature range from 150 to 600 K. It can be usedoutside these ranges with reduced accuracy for thicker speci-mens and for thermal conductivity

5、 values up to 60 Wm-1K-1.NOTE 1A body is considered homogeneous when the property to bemeasured is found to be independent of specimen dimensions.1.2 This test method is similar in concept to Test MethodC518, but is modified to accommodate smaller test specimens,having a higher thermal conductance.

6、In addition, significantattention has been paid to ensure that the thermal resistance ofcontacting surfaces is minimized and reproducible.1.3 The values stated in SI units are to be regarded asstandard. The additional values are mathematical conversionsto inch-pound units that are provided for infor

7、mation only andare not considered standard.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 regulato

8、ry limitations prior to use.2. Related Documents2.1 ASTM Standards:2C518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC1045 Practice for CalculatingThermalTransmission Prop-erties Under Steady-State ConditionsE220 Test Method for Calibration of

9、 Thermocouples ByComparison TechniquesE1142 Terminology Relating to Thermophysical PropertiesE1225 Test Method for Thermal Conductivity of Solids byMeans of the Guarded-Comparative-Longitudinal HeatFlow TechniqueF104 Classification System for Nonmetallic Gasket Mate-rialsF433 Practice for Evaluating

10、 Thermal Conductivity of Gas-ket Materials3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 heat flux transducer (HFT)a device that produces anelectrical output that is a function of the heat flux, in apredefined and reproducible manner.3.1.2 thermal conductance (C)the time rate

11、 of heat fluxthrough a unit area of a body induced by unit temperaturedifference between the body surfaces.3.1.2.1 average temperature of a surfacethe area-weighted mean temperature of that surface.3.1.2.2 average (mean) temperature of a specimen (discshaped)the mean value of the upper and lower fac

12、e tempera-tures.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.05 on Thermo-physical Properties.Current edition approved Aug. 15, 2011. Published September 2011. Originallyapproved in 1993. Last previous ed

13、ition approved in 2006 as E1530 06. DOI:10.1520/E1530-11.2For 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.1Cop

14、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.3 thermal conductivity (l)(of a solid material)thetime rate of heat flow, under steady conditions, through unitarea, per unit temperature gradient in the direction perpendicu-lar to the

15、 area:3.1.3.1 apparent thermal conductivitywhen other modesof heat transfer through a material are present in addition toconduction, the results of the measurements performed inaccordance with this test method will represent the apparent oreffective thermal conductivity for the material tested.3.1.4

16、 thermal resistance (R)the reciprocal of thermalconductance.3.2 Symbols:3.2.1 lthermal conductivity, Wm-1K-1or Btuin.h-1ft-2F-1.3.2.2 Cthermal conductance, Wm-2K-1or Btuh-1ft-2F-1.3.2.3 Rthermal resistance, m2KW-1or hft2FBtu-1.3.2.4 Dxspecimen thickness, mm or in.3.2.5 Aspecimen cross-sectional area

17、, m2or ft2.3.2.6 Qheat flow, W or Btuh-1.3.2.7 fheat flux transducer output, mV.3.2.8 Nheat flux transducer calibration constant,Wm-2mV-1or Btuh-1ft-2mV-1.3.2.9 Nfheat flux, Wm2or Btuh-1ft2.3.2.10 DTtemperature difference, C or F.3.2.11 Tgtemperature of guard heater, C or F.3.2.12 Tutemperature of u

18、pper heater, C or F.3.2.13 Tltemperature of lower heater, C or F.3.2.14 T1temperature of one surface of the specimen, Cor F.3.2.15 T2temperature of the other surface of the speci-men, C or F.3.2.16 Tmmean temperature of the specimen, C or F.3.2.17sunknown specimen.3.2.18rknown calibration or referen

19、ce specimen.3.2.19ocontacts.4. Summary of Test Method4.1 A specimen and a heat flux transducer (HFT) aresandwiched between two flat plates controlled at differenttemperatures, to produce a heat flow through the test stack. Areproducible load is applied to the test stack by pneumatic orother means, t

20、o ensure that there is a reproducible contactresistance between the specimen and plate surfaces. A guardsurrounds the test stack and is maintained at a uniform meantemperature of the two plates, in order to minimize lateral heatflow to and from the stack. At steady state, the difference intemperatur

21、e between the surfaces contacting the specimen ismeasured with temperature sensors embedded in the surfaces,together with the electrical output of the HFT. This output(voltage) is proportional to the heat flow through the specimen,the HFT and the interfaces between the specimen and theapparatus. The

22、 proportionality is obtained through prior cali-bration of the system with specimens of known thermalresistance measured under the same conditions, such thatcontact resistance at the surfaces is made reproducible.5. Significance and Use5.1 This test method is designed to measure and comparethermal p

23、roperties of materials under controlled conditions andtheir ability to maintain required thermal conductance levels.6. Apparatus6.1 Aschematic rendering of a typical apparatus is shown inFig. 1. The relative position of the HFT to the specimen is notimportant (it may be on the hot or cold side) as t

24、he test methodis based on maintaining axial heat flow with minimal radialheat losses or gains. It is also up to the designer whether tochoose heat flow upward or downward or horizontally, al-though downward heat flow in a vertical stack is the mostcommon one.6.2 Key Components of a Typical Device (T

25、he numbers 1 to22 in parentheses refer to Fig. 1):6.2.1 The compressive force for the stack is to be providedby either a regulated pneumatic or hydraulic cylinder (1), deadweights or a spring loaded mechanism. In either case, meansmust be provided to ensure that the loading can be varied andset to c

26、ertain values reproducibly.6.2.2 The loading force must be transmitted to the stackthrough a gimball joint (2) that allows up to 5 swivel in theplane perpendicular to the axis of the stack.6.2.3 Suitable insulator plate (3) separates the gimball jointfrom the top plate (4).6.2.4 The top plate (assum

27、ed to be the hot plate for thepurposes of this description) is equipped with a heater (5) andcontrol thermocouple (6) adjacent to the heater, to maintain acertain desired temperature. (Other means of producing andmaintaining temperature may also be used as long as therequirements in 6.3 are met.) Th

28、e construction of the top plateis such as to ensure uniform heat distribution across its facecontacting the specimen (8). Attached to this face (or embed-ded in close proximity to it) in a fashion that does not interferewith the specimen/plate interface, is a temperature sensor (7)(typically a therm

29、ocouple, resistance thermometer, or a therm-istor) that defines the temperature of the interface on the plateside.6.2.5 The specimen (8) is in direct contact with the top plateon one side and an intermediate plate (9) on the other side.6.2.6 The intermediate plate (9) is an optional item. Itspurpose

30、 is to provide a highly conductive environment to thesecond temperature sensor (10), to obtain an average tempera-ture of the surface. If the temperature sensor (10) is embeddedinto the face of the HFT, or other means are provided to definethe temperature of the surface facing the specimen, the use

31、ofthe intermediate plate is not mandatory.6.2.7 The heat flux transducer (HFT) is a device that willgenerate an electrical signal in proportion to the heat fluxacross it. The level of output required (sensitivity) greatlydepends on the rest of the instrumentation used to read it. Theoverall performa

32、nce of the HFTand its readout instrumentationshall be such as to meet the requirements in Section 13.6.2.8 The lower plate (12) is constructed similarly to theupper plate (4), except it is positioned as a mirror image.E1530 1126.2.9 An insulator plate (16) separates the lower plate (12)from the heat

33、 sink (17). In case of using circulating fluid inplace of a heater/thermocouple arrangement in the upper orlower plates, or both, the heat sink may or may not be present.6.2.10 The entire stack is surrounded by a guard whosecross section is not too much different from the stacks (18)equipped with a

34、heater or cooling coils (19), or both, and acontrol thermocouple, resistance thermometer or thermistor(20) to maintain it at the mean temperature between the upperand lower plates. A small, generally unfilled, gap separates theguard from the stack. For instruments limited to operate in theambient re

35、gion, no guard is required but a draft shield isrecommended in place of it.NOTE 2It is permissible to use thin layers of high-conductivity greaseor elastomeric material on the two surfaces of the specimen to reduce thethermal resistance of the interface and promote uniform thermal contactacross the

36、interface area.NOTE 3The cross-sectional area and the shape of the specimen maybe any, however, most commonly circular and rectangular cross sectionsare used. Minimum size is dictated by the magnitude of the disturbancecaused by thermal sensors in relation to the overall flux distribution. Themost c

37、ommon sizes are 25 mm round or square to 50 mm round.6.2.11 The instrument is preferably equipped with suitablemeans (21) to measure the thickness of the specimen, in situ, inaddition to provisions (22) to limit compression when testingelastomeric or other compressible materials.NOTE 4This requireme

38、nt is also mandatory for testing materials thatsoften while heated.6.3 Requirements:6.3.1 Temperature control of upper and lower plate is to be60.1 C (0.18 F) or better.6.3.2 Reproducible load of 0.28 MPa (40 psi) has beenfound to be satisfactory for solid specimens. Minimum loadshall not be below 0

39、.07 MPa (10 psi).6.3.3 Temperature sensors are usually fine gage or small-diameter sheath thermocouples, however, ultraminiature resis-tance thermometers and linear thermistors may also be used.6.3.4 Operating range of a device using a mean temperatureguard shall be limited to from 100 to 300 C, whe

40、n usingthermocouples as temperature sensors, and from 180 to300 C when platinum resistance thermometers are used.Thermistors are normally present on more restricted allowabletemperature range of use.7. Sampling and Conditioning7.1 Cut representative test specimens from larger pieces ofthe sample mat

41、erial or body.7.2 Condition the cut specimens in accordance with therequirements of the appropriate material specifications, if any.8. Test Specimen8.1 The specimen to be tested should be representative forthe sample material. The recommended specimen configura-tion is a 50.8 6 0.25 mm (2 6 0.010 in

42、.) diameter disk, havingsmooth flat and parallel faces, 60.025 mm (60.001 in.), suchthat a uniform thickness within 60.025 mm (60.001 in.) isattained in the range from 0.5 to 25.4 mm (0.020 to 1.0 in.) Fortesting specimens with thicknesses below 0.5 mm, a specialtechnique, described in Annex A1, has

43、 to be used. Otherfrequently favored sizes are 25.4 mm (1.00 in.) round or squarecross section.FIG. 1 Key Components of a Typical DeviceE1530 1139. Calibration9.1 Select the mean temperature and load conditions re-quired. Adjust the upper heater temperature (Tu) and lowerheater temperature (Tl) such

44、 that the temperature difference atthe required mean temperature is no less than 30 to 35 C andthe specimen DT is not less than 3 C. Adjust the guard heatertemperature (Tg) such that it is at approximately the average ofTuand Tl.9.2 Select at least three calibration specimens having ther-mal resista

45、nce values that bracket the range expected for thetest specimens at the temperature conditions required.9.3 Table 1 contains a list of several available materialscommonly used for calibration together with correspondingthermal resistance (Rs) values for a given thickness. Thisinformation is provided

46、 to assist the user in selecting optimumspecimen thickness for testing a material and in deciding whichcalibration specimens to use.9.4 The range of thermal conductivity for which this testmethod is most suitable is such that the optimum thermalresistance range is from 10 3 10-4to 400 3 10-4m2KW-1.T

47、he most commonly used calibration materials are the Pyrex7740 and Pyroceram 9606,3Vespel4(polyimide) and stainlesssteel all having well-established thermal conductivity behav-iors with temperature.9.5 Table 2 and Table 3 are listing thermal conductivityvalues for selected reference materials, with t

48、he appropriatebibliographic references appearing in bold characters. Thetemperature range listed for each reference material corre-sponds to the temperature range mentioned in each particularcited work, and in some cases exceeds the applicable tempera-ture range for this test method. The information

49、 was, however,considered useful for the general user, and for that reason itwas listed for the entire temperature range applicable to eachreference material.10. Procedure10.1 Measure the thickness of the calibration specimen to25 m using a suitable caliper or gauge stand.10.2 Coat both surfaces of a calibration specimen with avery thin layer of a compatible heat transfer compound or placea thin layer of elastomeric heat-transfer medium on it to helpminimize the thermal resistance at the int