ASTM C1044-2016 Standard Practice for Using a Guarded-Hot-Plate Apparatus or Thin-Heater Apparatus in the Single-Sided Mode《使用单面护热板设备或薄型加热器设备的标准实施规程》.pdf

1、Designation: C1044 16Standard Practice forUsing a Guarded-Hot-Plate Apparatus or Thin-HeaterApparatus in the Single-Sided Mode1This standard is issued under the fixed designation C1044; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio

2、n, 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 practice covers the determination of the steady-state heat flow through the meter section of a spe

3、cimen whena guarded-hot-plate apparatus or thin-heater apparatus is usedin the single-sided mode of operation.1.2 This practice provides a supplemental procedure for usein conjunction with either Test Method C177 or C1114 fortesting a single specimen. This practice is limited to only thesingle-sided

4、 mode of operation, and, in all other particulars, therequirements of either Test Method C177 or C1114 apply.NOTE 1Test Methods C177 and C1114 describe the use of theguarded-hot-plate and thin-heater apparatus, respectively, for determiningsteady-state heat flux and thermal transmission properties o

5、f flat-slabspecimens. In principle, these methods cover both the double- andsingle-sided mode of operation, and at present, do not distinguish betweenthe accuracies for the two modes of operation. When appropriate, thermaltransmission properties shall be calculated in accordance with PracticeC1045.1

6、.3 This practice requires that the cold plates of the appa-ratus have independent temperature controls. For the single-sided mode of operation, a (single) specimen is placed betweenthe hot plate and the cold plate. Auxiliary thermal insulation, ifneeded, is placed between the hot plate and the auxil

7、iary coldplate. The auxiliary cold plate and the hot plate are maintainedat the same temperature. The heat flow from the meter plate isassumed to flow only through the specimen, so that the thermaltransmission properties correspond only to the specimen.NOTE 2The double-sided mode of operation requir

8、es similar speci-mens placed on either side of the hot plate. The cold plates that contact theouter surfaces of these specimens are maintained at the same temperature.The electric power supplied to the meter plate is assumed to result in equalheat flow through the meter section of each specimen, so

9、that the thermaltransmission properties correspond to an average for the two specimens.1.4 This practice does not preclude the use of a guarded-hot-plate apparatus in which the auxiliary cold plate is eitherlarger or smaller in lateral dimensions than either the testspecimen or the cold plate.NOTE 3

10、Most guarded-hot-plate apparatus are designed for the double-sided mode of operation (1).2Consequently, the cold plate and theauxiliary cold plate are the same size and the specimen and the auxiliaryinsulation will have the same lateral dimensions, although the thicknessesneed not be the same. Some

11、guarded-hot-plate apparatus, however, aredesigned specifically for testing only a single specimen that is either largeror smaller in lateral dimensions than the auxiliary insulation or theauxiliary cold plate.1.5 This practice is suitable for use for both low- andhigh-temperature conditions.1.6 This

12、 practice shall not be used when operating anapparatus in a double-sided mode of operation with a knownand unknown specimen, that is, with the two cold plates atsimilar temperatures so that the temperature differences acrossthe known and unknown specimens are similar.1.7 This standard does not purpo

13、rt 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 regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3C168

14、 Terminology Relating to Thermal Insulation3C177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate Apparatus3C518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter Apparatus3C1045 Practi

15、ce for Calculating Thermal Transmission Prop-erties Under Steady-State Conditions3C1114 Test Method for Steady-State Thermal TransmissionProperties by Means of the Thin-Heater Apparatus3. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, refer to Terminology C168. For definiti

16、ons of terms1This practice is under the jurisdiction of ASTM Committee C16 on ThermalInsulation and is the direct responsibility of Subcommittee C16.30 on ThermalMeasurement.Current edition approved Sept. 1, 2016. Published September 2016. Originallyapproved in 1985. Last previous edition approved i

17、n 2012 as C1044 12. DOI:10.1520/C1044-16.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume i

18、nformation, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1relating to the guarded-hot-plate apparatus or thin-heater ap-paratus refer to Test Methods C177 or C1114, res

19、pectively,3.2 Definitions of Terms Specific to This Standard:3.2.1 auxiliary cold plate, nthe plate that provides anisothermal boundary at the outside surface of the auxiliaryinsulation.3.2.2 auxiliary insulation, nthermal insulation used inplace of a second test specimen, when the single-sided mode

20、 ofoperation is used (syn. dummy specimen).3.2.3 cold plate, nthe plate that provides an isothermalboundary at the cold surface of the specimen.3.2.4 double-sided mode, noperation of the apparatus,such that the heat input to the meter plate flows equally throughtwo specimens, each specimen placed on

21、 either side of the hotplate (see also single-sided mode).3.2.5 gap, nseparation between the meter plate and guardplate, usually filled with a gas or thermal insulation.3.2.6 guard plate, nthe outer (rectangular or circular) ringof the guarded hot plate, that encompasses the meter plate andpromotes

22、one-dimensional heat flow normal to the meter plate.3.2.7 guarded hot plate, nan assembly, consisting of ameter plate and a co-planar, concentric guard plate, thatprovides the heat input to the specimen(s).3.2.8 meter plate, nthe inner (rectangular or circular) plateof the guarded hot plate, that pr

23、ovides the heat input to themeter section of the specimen(s).3.2.9 meter section, nthe portion of the specimen (orauxiliary insulation) through which the heat input to the meterplate flows under ideal guarding conditions.3.2.10 single-sided mode, noperation of the apparatussuch that essentially all

24、of the heat input to the meter plateflows through a specimen placed on one side of the hot plate(see also double-sided mode).3.2.11 thin heater, nan assembly, consisting of an unpar-titioned thin-screen heater or thin-foil, that provides the heatinput to the specimen(s).3.3 SymbolsThe symbols used i

25、n this practice have thefollowing significance. The prime () denotes quantities asso-ciated with the auxiliary insulation used to control heat fromthe other side of the hot plate.3.3.1 Ameter area of hot plate, m2.3.3.2 Cthermal conductance of auxiliary insulation,W/(m2 K).3.3.3 Qheat flow through m

26、eter section of specimen, W.3.3.4 Qheat flow through meter section of auxiliaryinsulation, W.3.3.5 Qmpower input to meter plate, W.3.3.6 Tcsurface temperature of cold plate, K.3.3.7 Tcsurface temperature of auxiliary cold plate, K.3.3.8 Thsurface temperature of hot plate in contact withspecimen, K.3

27、.3.9 Thsurface temperature of hot plate in contact withauxiliary insulation, K.4. Significance and Use4.1 This practice provides a procedure for operating theapparatus so that the heat flow, Q, through the meter section ofthe auxiliary insulation is small; determining Q; and, calculat-ing the heat f

28、low, Q, through the meter section of the specimen.4.2 This practice requires that the apparatus have indepen-dent temperature controls in order to operate the cold plate andauxiliary cold plate at different temperatures. In the single-sides mode, the apparatus is operated with the temperature ofthe

29、auxiliary cold plate maintained at the same temperature ofthe hot plate face adjacent to the auxiliary insulation.NOTE 4In principle, if the temperature difference across the auxiliaryinsulation is zero and there are no edge heat losses or gains, all of thepower input to the meter plate will flow th

30、rough the specimen. In practice,a small correction is made for heat flow, Q, through the auxiliaryinsulation.4.3 The thermal conductance, C, of the auxiliary insulationshall be determined from one or more separate tests usingeither Test Method C177, C1114, or as indicated in 5.4. Valuesof C shall be

31、 checked periodically, particularly when thetemperature drop across the auxiliary insulation less than 1 %of the temperature drop across the test specimen.4.4 This practice is used when it is desirable to determinethe thermal properties of a single specimen. For example, thethermal properties of a s

32、ingle specimen are used to calibrate aheat-flow-meter apparatus for Test Method C518.5. Procedure for Single-Sided Mode of Operation5.1 Refer to Fig. 1 for a schematic diagram of the single-sided mode of operation of the guarded-hot-plate apparatus.NOTE 5The schematic diagram for a thin-heater appar

33、atus (notshown) is similar, except the hot plate is much thinner and is notpartitioned by a gap.5.2 Follow the procedure of either Test Method C177 orC1114 with the following modifications.5.3 Select a rigid or semi-rigid material for the auxiliaryinsulation having a low thermal conductance so that

34、heat gainsor losses from the face of the meter plate in contact with theauxiliary insulation will be small. The thickness and lateralconductance of the auxiliary insulation shall be small to avoidsignificant effects on the heat transfer through the meter sectionof the auxiliary insulation due to hea

35、t transfer at the edge of theauxiliary insulation.NOTE 6The influence of edge effects for a particular apparatus andtest configuration is determined experimentally as described in TestMethod C177 or by computation using one of the procedures referencedin Test Method C177 or described by Peavy and Re

36、nnex (2).5.4 Determine C of the auxiliary insulation over the tem-perature range of interest using one of the following proce-dures: (1) Test Method C177 or C1114 in a separate test setupfor a matched pair of similar specimens; or (2) in-situ asdescribed in Annex A1.5.4.1 In the first instance, usin

37、g either Test Method C177 orC1114, a matched pair of similar specimens is required so thateither single specimen subsequently is suitable for use as theauxiliary insulation.C1044 1625.4.2 In the second instance using in-situ as described inAnnex A1, successive tests are required, one with a smalltem

38、perature difference across the test specimen and one with asmall temperature difference across the auxiliary insulation.NOTE 7In 5.4 the user is not required to determine values for C forevery test that will be conducted. Rather, determine Cas a function oftemperature over the temperature range of i

39、nterest so that a correspondingregression curve is developed for subsequent testing.5.5 When using a compressible material as the auxiliaryinsulation, determine Ceither at the same thickness as thatused in the single-sided mode of operation or compressed to (atleast) two slightly different thickness

40、es, thus allowing interpo-lation for the thickness actually used in the single-sided modeof operation.5.5.1 For an apparatus without a separate provision fordetermining the individual thicknesses of the two specimens onopposite sides of the hot plate, place three or more low-conductance rigid spacer

41、s near the outer periphery of the guardplate between the hot plate and the surface of the auxiliary coldplate.5.5.2 Compute the effective thickness of the test specimenby subtracting the thickness of the rigid spacers (corrected forthermal expansion, if necessary) from the thickness that isdetermine

42、d for the test specimen plus the auxiliary insulation.In this case, the separate tests of thermal conductance accord-ing to 5.4.2 shall be conducted with rigid spacers.5.6 Maintain the cold plate at the required temperature Tc.Provide power input to the hot plate to attain the requiredtemperature Th

43、on the hot side of the test specimen.5.7 Maintain the temperature Tcas closely as practical tothe temperature Th.5.8 Establish thermal steady-state conditions in accordancewith either Test Method C177 or C1114.5.9 Acquire the required test data and determine A, Qm,Th,Th, and Tcin accordance with eit

44、her Test Method C177 orC1114.6. Calculation6.1 Calculate the heat flow through the auxiliary insulationas follows:Q 5 C A Th2 Tc! (1)where:Cis the thermal conductance of the auxiliary insulation at atemperature corresponding to (Th+Tc)/2, as obtained accord-ing to 5.4.6.2 Calculate the heat flow thr

45、ough the specimen as follows:Q 5 Qm2 Q (2)6.3 Use the value of Q, thus obtained to calculate steady-state thermal transmission properties, in accordance with eitherTest Method C177 or C1114. When appropriate, consultPractice C1045 to calculate steady-state thermal transmissionproperties. For referen

46、ce, calculation equations are provided inAppendix X1.7. Sources of Experimental Error7.1 Errors in the determination of Q, are introduced fromseveral sources, including measurement of the power input Qmto the meter plate; estimation of the heat flow, Q, through theauxiliary insulation and, for guard

47、ed hot plates, estimation ofthe heat flow across the gap between the meter plate and guardplate, that is, gap error.7.2 Refer to either Test Method C177 or C1114 for discus-sion on the uncertainty in the measurement of the metered-areapower (Qm).FIG. 1 Diagram Illustrating Single-Sided Mode of Opera

48、tion of the Guarded-Hot-Plate ApparatusC1044 1637.3 Estimate the uncertainty (Q) in Q by a propagation oferror using the terms in Eq 1. Refer to Ku (3) for using errorpropagation formulas.NOTE 8When the terms Qmand QinEq 2 are different by at least twoorders of magnitude, a large uncertainty in Q re

49、sults in a small uncertaintyin Q. For example, suppose that the ratio Qm/Q is 100 and suppose thatthe ratio Q/Q is 0.1. The percentage uncertainty in Q due to Q, then,would be 0.1 %.7.4 Refer to Appendix X2 for a discussion of the gap error.7.5 Refer to Appendix X3 for a discussion on Precision andBias and Measurement Uncertainty.8. Report8.1 Report all measurements in accordance with either TestMethod C177 or C1114. Perform all calculations in accordancewith Practice C1045. The report shall note that the appar