1、Designation: E 1530 06Standard Test Method forEvaluating the Resistance to Thermal Transmission ofMaterials by the Guarded Heat Flow Meter Technique1This standard is issued under the fixed designation E 1530; 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 (e) 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 re
3、sistance to thermal transmission (ther-mal resistance) of materials in thicknesses of 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 ra
4、nge from 10 to 400 3 104m2K/W, whichcan be obtained from materials of thermal conductivity in theapproximate range from 0.1 to 30 W/(mK) over 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 conducti
5、vity values up to 60 W/(mK).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 MethodC 518, but is modified to accommodate smaller test specimens,having a higher thermal conductan
6、ce. 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 considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its
7、 use. It is theresponsibility 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.2. Related Documents2.1 ASTM Standards:2C 518 Test Method for Steady-State Thermal TransmissionProperties by Means
8、of the Heat Flow Meter ApparatusC 1045 Practice for Calculating Thermal TransmissionProperties Under Steady-State ConditionsE 220 Test Method for Calibration of Thermocouples ByComparison TechniquesE 1142 Terminology Relating to Thermophysical PropertiesE 1225 Test Method for Thermal Conductivity of
9、 Solids byMeans of the Guarded-Comparative-Longitudinal HeatFlow TechniqueF 104 Classification System for Nonmetallic Gasket Mate-rialsF 433 Practice for Evaluating Thermal Conductivity ofGasket Materials3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 heat flux transducer (HFT
10、)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 of heat fluxthrough a unit area of a body induced by unit temperaturedifference between the body surfaces.3.1.2.1 average temperature of
11、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 face tempera-tures.3.1.3 thermal conductivity (l)(of a solid material)thetime rate of heat flow, under steady conditions, through unitarea, p
12、er unit temperature gradient in the direction perpendicu-lar to the 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 appa
13、rent oreffective thermal conductivity for the material tested.3.1.4 thermal resistance (R)the reciprocal of thermalconductance.3.2 Symbols:3.2.1 lthermal conductivity, W/(mK) or Btuin./(hft2F).3.2.2 Cthermal conductance, W/m(2K) or Btu/(hft2F).1This test method is under the jurisdiction ofASTM Commi
14、ttee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.05 on Thermo-physical Properties.Current edition approved Sept. 1, 2006. Published November 2006. Originallyapproved in 1993. Last previous edition approved in 2004 as E 1530 04.2For referenced ASTM standards, visit
15、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-295
16、9, United States.3.2.3 Rthermal resistance, m2K/W or hft2F/Btu.3.2.4 Dxspecimen thickness, mm or in.3.2.5 Aspecimen cross-sectional area, m2or ft2.3.2.6 Qheat flow, W or Btu/h.3.2.7 fheat flux transducer output, mV.3.2.8 Nheat flux transducer calibration constant,W/(m2mV) or Btu/(hft2mV).3.2.9 Nfhea
17、t flux, W/m2or Btu/hft2.3.2.10 DTtemperature difference,C or F.3.2.11 Tgtemperature of guard heater, C or F.3.2.12 Tutemperature of upper 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 o
18、f 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 reference 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 differenttempe
19、ratures, to produce a heat flow through the test stack. Areproducible load is applied to the test stack by pneumatic orother means, to ensure that there is a reproducible contactresistance between the specimen and plate surfaces. A guardsurrounds the test stack and is maintained at a uniform meantem
20、perature of the two plates, in order to minimize lateral heatflow to and from the stack. At steady state, the difference intemperature between the surfaces contacting the specimen ismeasured with temperature sensors embedded in the surfaces,together with the electrical output of the HFT. This output
21、(voltage) is proportional to the heat flow through the specimen,the HFT and the interfaces between the specimen and theapparatus. The proportionality is obtained through prior cali-bration of the system with specimens of known thermalresistance measured under the same conditions, such thatcontact re
22、sistance at the surfaces is made reproducible.5. Significance and Use5.1 This test method is designed to measure and comparethermal properties of materials under controlled conditions andtheir ability to maintain required thermal conductance levels.6. Apparatus6.1 Aschematic rendering of a typical a
23、pparatus is shown inFig. 1. The relative position of the HFT to sample is notimportant (it may be on the hot or cold side) as the 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
24、 horizontally, al-though downward heat flow in a vertical stack is the mostcommon one.6.2 Key Components of a Typical Device (The 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), deadw
25、eights or a spring loaded mechanism. In either case, meansmust be provided to ensure that the loading can be varied andset to certain values reproducibly.FIG. 1 Key Components of a Typical DeviceE15300626.2.2 The loading force must be transmitted to the stackthrough a gimball joint (2) that allows u
26、p 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 (assumed to be the hot plate for thepurposes of this description) is equipped with a heater (5) andcontrol thermocouple (6) adjace
27、nt 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.) The construction of the top plateis such as to ensure uniform heat distribution across its facecontacting the sample (8). Atta
28、ched to this face (or embeddedin close proximity to it) in a fashion that does not interfere withthe sample/plate interface, is a temperature sensor (7) (typi-cally a thermocouple, resistance thermometer, or a thermistor)that defines the temperature of the interface on the plate side.6.2.5 The sampl
29、e (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 is to provide a highly conductive environment to thesecond temperature sensor (10), to obtain an average tempera-ture of the surfa
30、ce. 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 sample, the use of theintermediate plate is not mandatory.6.2.7 The heat flux transducer (HFT) is a device that willgenerate an electrical signal in
31、proportion to the heat fluxacross it. The level of output required (sensitivity) greatlydepends on the rest of the instrumentation used to read it. Theoverall performance of the HFTand its readout instrumentationshall be such as to meet the requirements in Section 13.6.2.8 The lower plate (12) is co
32、nstructed similarly to theupper plate (4), except it is positioned as a mirror image.6.2.9 An insulator plate (16) separates the lower plate (12)from the heat sink (17). In case of using circulating fluid inplace of a heater/thermocouple arrangement in the upper orlower plates, or both, the heat sin
33、k 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 heater and/or cooling coils (19) and a controlthermocouple, resistance thermometer or thermistor (20) tomaintain it at the mean temperature be
34、tween the upper andlower plates. A small, generally unfilled, gap separates theguard from the stack. For instruments limited to operate in theambient region, 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
35、elastomeric material on the two surfaces of the sample to reduce thethermal resistance of the interface and promote uniform thermal contactacross the interface area.NOTE 3The cross-sectional area and the shape of the sample may beany, however, most commonly circular and rectangular cross sections ar
36、eused. Minimum size is dictated by the magnitude of the disturbancecaused by thermal sensors in relation to the overall flux distribution. Themost common 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 th
37、e sample, in situ, inaddition to provisions (22) to limit compression when testingelastomeric or other compressible materials.NOTE 4This requirement is also mandatory for testing materials thatsoften while heated.6.3 Requirements:6.3.1 Temperature control of upper and lower plate is to be6 0.1 C (0.
38、18 F) or better.6.3.2 Reproducible load of 0.28 MPa (40 psi) has beenfound to be satisfactory for solid samples. Minimum load shallnot be below 0.07 MPa (10 psi).6.3.3 Temperature sensors are usually fine gage or small-diameter sheath thermocouples, however, ultraminiature resis-tance thermometers a
39、nd 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, when usingthermocouples as temperature sensors, and from 180 to 300C when platinum resistance thermometers are used. Ther-mistors are normally present on more
40、 restricted allowabletemperature range of use.7. Sampling and Conditioning7.1 Cut representative test specimens from larger pieces ofthe sample material or body.7.2 Condition the cut specimens in accordance with therequirements of the appropriate material specifications, if any.8. Test Specimen8.1 T
41、he specimen to be tested should be representative forthe sample material. The recommended specimen configura-tion is a 50.86 0.25 mm (2 6 0.010 in.) diameter disk, havingsmooth flat and parallel faces, 6 0.025 mm (6 0.001 in.), suchthat a uniform thickness within 0.025 mm (6 0.001 in.) isattained in
42、 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 to be used. Otherfrequently favored sizes are 25.4 mm (1.00 in.) round or squarecross section.9. Calibration9.1 Select the mean temperature and load co
43、nditions re-quired. Adjust the upper heater temperature (Tu) and lowerheater temperature (Tl) such 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 approximat
44、ely the average ofTuand Tl.9.2 Select at least three calibration specimens having ther-mal resistance 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 w
45、ith correspondingthermal resistance (Rs) values for a given thickness. Thisinformation is provided 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 mos
46、t suitable is such that the optimum thermalresistance range is from 10 3 104to 400 3 104m2K/W. TheE1530063most commonly used calibration materials are the Pyrexy77403and Pyroceramy 96063, Vespely (polyimide) andstainless steel all having well-established thermal conductivitybehaviors with temperatur
47、e.49.5 Table 2 and Table 3 are listing thermal conductivityvalues for selected reference materials, with the appropriatebibliographic references appearing in bold characters. Thetemperature range listed for each reference material corre-sponds to the temperature range mentioned in each particularcit
48、ed work, and in some cases exceeds the applicable tempera-ture range for this test method. The information 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 thickne
49、ss 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 interfaces of adjacentcontacting surfaces.10.3 Release the compressive load on the specimen stack,open the test chamber, and insert the calibration specimen.Care must be taken to ensure that all surfaces are free
