1、Designation: E1952 11E1952 17Standard Test Method forThermal Conductivity and Thermal Diffusivity by ModulatedTemperature Differential Scanning Calorimetry1This standard is issued under the fixed designation E1952; the number immediately following the designation indicates the year oforiginal adopti
2、on or, in 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. Scope Scope*1.1 This test method describes the determination of thermal conductivit
3、y of homogeneous, non-porous solid materials in therange of 0.10 W/(K m) to 1.0 W(K m) by modulated temperature differential scanning calorimeter. This range includes manypolymeric, glass, and ceramic materials. Thermal diffusivity, which is related to thermal conductivity through specific heat capa
4、cityand density, may also be derived. Thermal conductivity and diffusivity can be determined at one or more temperatures over therange of 00C to 90C.1.2 The values stated in SI units are the to be regarded as standard. The values given in parentheses are mathematicalconversions to inch-pound units t
5、hat are provided for information purposes only.only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health and healt
6、henvironmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Stand
7、ards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and RheologyE967 Test Method for Temperature Calibration of Differential Scanning Calorimeters a
8、nd Differential Thermal AnalyzersE968 Practice for Heat Flow Calibration of Differential Scanning CalorimetersE1142 Terminology Relating to Thermophysical PropertiesE1231 Practice for Calculation of Hazard Potential Figures of Merit for Thermally Unstable MaterialsE2161 Terminology Relating to Perfo
9、rmance Validation in Thermal Analysis and Rheology3. Terminology3.1 Definitions:3.1.1 Specific technical terms used in this document test method are defined in Terminologies E473, E1142, and E2161including calibration, differential scanning calorimetry, heat capacity, modulated temperature, precisio
10、n, reference material,relative standard deviation, repeatability, reproducibility, specific heat capacity, standard deviation, thermal analysis, thermalconductance, and thermal conductivity.3.2 Definitions of Terms Specific to This Standard:3.2.1 modulated temperature differential scanning calorimet
11、era version of differential scanning calorimetry that provides asinusoidally varying temperature program to the test specimen in addition to the traditional isothermal or temperature rampprograms. Results from analysis shall include apparent and specific heat capacity.1 This test method is under the
12、 jurisdiction of Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.10 on Fundamental,Statistical and Mechanical Properties.Current edition approved Aug. 1, 2011Sept. 1, 2017. Published September 2011September 2017. Originally approved in 1998. Last previous e
13、dition approved in 20062011as E1952 11. DOI: 10.1520/E1952-11.10.1520/E1952-17.The process described in this test method is covered by a patent (Marcus, S. M. and Reading, M., U. S. Patent 5 335 993, 1994) held by TA Instruments, Inc., 159 LukensDrive, New Castle DE 19720. Interested parties are inv
14、ited to submit information regarding the identification of acceptable alternatives to this patented method to theCommittee on Standards,ASTM Headquarters, 100 Barr Harbor Drive, West Conshohocken PA19428-2959. Your comments will receive careful considerations at a meetingof the responsible technical
15、 committee which you may attend.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM
16、standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all
17、cases only the current versionof the standard as published by ASTM is to be considered the official document.*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 States14. Summary o
18、f Test Method4.1 The heat capacity of a test specimen may be determined using the modulated temperature approach in which an oscillatoryor periodically repeating temperature program (around an average temperature) is imposed upon a test specimen producing anoscillatory (periodic) heat flow into or o
19、ut of the specimen. The heat capacity of the test specimen may be obtained from theamplitude of the resultant heat flow divided by the amplitude of the oscillatory (periodic) temperature that produces it. Specificheat capacity is obtained by normalizing the heat capacity to specimen mass.4.1.1 The a
20、ccuracy of the heat capacity thus obtained depends upon experimental conditions. When a thin test specimenencapsulated in a specimen pan of high thermal conductivity is treated with temperature oscillations of long period (lowfrequency), the test specimen is assumed to achieve a uniform temperature
21、distribution and the resultant heat capacity informationwill be comparable with those of other non-oscillatory test methods.4.1.2 When one end of a thick test specimen is exposed to the temperature oscillations of short period (high frequency), the testspecimen will achieve a temperature distributio
22、n over its length related to its thermal diffusivity.4.1.3 The apparent heat capacity information thus obtained is lower than that of the uniform temperature distribution casedescribed above and is proportional to the square root of thermal conductivity of the test specimens (1).3 The thermal conduc
23、tivityof the test specimen may be derived from the apparent heat capacity of a thick specimen, the actual heat capacity of a thinspecimen, and a series of geometric and experimental constants.4.2 If the thermal conductivity of the test specimen is low, approaching that of the purge gas surrounding i
24、t, a correction to themeasured thermal conductivity is required to compensate for heat losses from the thick test specimen.4.3 Thermal diffusivity is derived from the determined thermal conductivity, specific heat capacity, and density of the testspecimen.5. Significance and Use5.1 Thermal conductiv
25、ity is a useful design parameter for the rate of heat transfer through a material.5.2 The results of this test method may be used for design purposes, service evaluation, manufacturing control, research anddevelopment, and hazard evaluation. (See Practice E1231.)6. Interferences6.1 Because the speci
26、men size used in thermal analysis is on the order of 10 mg to 100 mg, care must be taken to ensure it ishomogeneous or representative of the material, or both.6.2 The calculation of thermal conductivity requires knowledge of this specimen geometry. This test method requires a specificspecimen size a
27、nd shape. Other geometries may be used with the appropriate modifications to the calculating equations.7. Apparatus7.1 A modulated temperature differential scanning calorimeter consisting of:7.1.1 A Differential Scanning Calorimetry (DSC) Test Chamber, of (1) a furnace to provide uniform controlled
28、heating/coolingof a specimen and reference to a constant temperature or at a constant rate within the applicable range of this test method; (2) atemperature sensor (or other signal source) to provide an indication of the specimen temperature readable to 0.01C; (3) adifferential sensor to detect a he
29、at flow difference between the specimen and reference equivalent to 0.001 mW; and (4) a meansof sustaining a test temperature environment of inert nitrogen purge gas at a rate of 50 mLmin 6 10 mLmin.7.1.2 A Temperature Controller, capable of executing a specific temperature program by (1) operating
30、the furnace betweenselected temperature limits at a rate of temperature change of 1C/min, (2) holding at an isothermal temperature over thetemperature range of 00C to 90C within 60.1C, and (3) sinusoidal varying temperature with an amplitude of 60.260.2C to0.7C and a period of 60 s to 100 seconds100
31、 s (frequency of 10 mHz to 16 mHz).NOTE 1The upper thermal conductivity achievable by this method is extended to 4 W (K m) for instruments capable of 20 second20 s periods(frequency of 50 mHz) (2).7.1.3 A Calculating Device, capable of transforming the experimentally determined modulated temperature
32、 and modulatedspecimen heat flow signals into the required continuous output forms of heat capacity (preferably in units of mJ/C),mJ/K), specificheat capacity (preferably in units of J/(g C), J/(g K), and average test temperature to the required accuracy and precision.7.1.4 AData Collecting Device,
33、to provide a means of acquiring, storing, and displaying measured or calculated signals, or both.The minimum output signals required are heat flow, temperature, time, heat capacity, specific heat capacity, and averagetemperature with a sensitivity of 0.001 mJK for heat capacity, 0.001 J(g K) for spe
34、cific heat capacity, 0.01C for averagetemperature, and 0.1 min for time.7.1.5 A Coolant System, to provide oscillatory heating and cooling rates of at least 3C/min.7.1.6 Inert Nitrogen, or other low conductivity purge gas flowing at a rate of 50 mLmin (see 7.1.1).3 The boldface numbers in parenthese
35、s refer to a list of references at the end of this standard.E1952 172NOTE 2Helium, a commonly used purge gas, is unacceptable for this purpose, due to its very high thermal conductivity which results in reducedrange, precision, and accuracy.7.2 A Balance, with a range of at least 200 mg to weigh spe
36、cimens or containers, or both, (pans, crucibles, etc.) to 60.01 mg.7.3 Calipers or other length-measuring device with a range greater than 4 mm, readable to 0.01 mm.7.4 Sapphire Disk Calibration Material, 20 mg to 30 mg.7.5 Polystyrene Thermal Conductivity Calibration Material, of known thermal cond
37、uctivity and specific heat capacity, in theshape of a right circular cylinder, 6.3 6 0.2 mm in diameter and 3.5 6 0.3 mm thickness.7.5.1 Polystyrene Specific Heat Capacity Reference Material, composed of the same material as the thermal conductivitycalibration material, in the shape of a right circu
38、lar cylinder or disk, 6.3 6 0.2 mm in diameter and 0.4 6 0.1 mm in thickness.7.6 Circular Aluminum Disk, 6.3 mm in diameter and 0.01 mm or thinner in thickness.7.7 Containers (pans, crucibles, etc.) that are inert to the specimen and are of suitable structural shape and integrity to containthe speci
39、men in accordance with the specific requirements of this test method.7.8 Silicone Heat Transfer Fluid, with no thermal transitions over the temperature range from 1010C to 100C.NOTE 3Silicone oil with a viscosity of about 1 Pa s (10 poise) has been found satisfactory for this application.7.9 While n
40、ot required, users may find the following optional apparatus and materials useful for this determination.7.9.1 Polymeric Thermal Conductivity Performance Material, a right circular cylinder, 6.3 6 0.2 mm in diameter and3.5 6 0.3 mm in length.7.9.2 Polymeric Specific Heat Capacity Reference Material,
41、 composed of the same material as the thermal conductivity standardreference material, a right circular cylinder or disk, 6.3 6 0.2 mm in diameter and 0.4 6 0.1 mm in thickness.8. Sampling8.1 Select two right circular cylinders, both nominally 6.3 mm in diameter.The first of these test specimens is
42、nominally 0.4 mmthick and the second is nominally 3.5 mm thick. These test specimens are most conveniently obtained by cutting from 0.25-in.diameter rod, a common material form.NOTE 4Other fabrication techniques, such as cutting from sheet stock using cork borers, machining from stock, or molding ma
43、y also be used.8.1.1 Polish the circular end surfaces of the test specimens smooth and parallel to within 630 m with 600 grit emery paper.9. Calibration9.1 Calibrate the temperature signal from the apparatus in accordance with Practice E967 using an indium reference materialand a heating rate of 1C/
44、min.9.2 Calibrate the heat flow signal from the apparatus in accordance with Practice E968 using an indium reference material.9.3 Calibrate the apparatus for heat capacity measurements in accordance with the instructions of the manufacturer as describedin the instrument manual using isothermal tempe
45、rature conditions (at the mid point mid-point of the temperature range of interest),the sapphire calibration material (from 7.4) 60.5C amplitude and 80-second 80 s period (12.5 mHz frequency).10. Procedure10.1 Measure thermal conductivity under quasi-isothermal conditions at an operator-selected tem
46、perature within the range from00C to 90C. If measurements at additional temperatures are desired, repeat the procedure at those additional temperatures.10.2 A common set of experimental conditions are used for each measurement:10.2.1 Select the modulated mode on the DSC and record the heat capacity
47、signal. Equilibrate the apparatus at the testtemperature selected by the operator. Modulate the temperature with an amplitude of 60.5C and a period (P) of 80 seconds80 s(12.5 mHz). (See Note 5.) After 15 min equilibration time, record the average test temperature (T) and the specific heat capacity(C
48、cpp) or apparent heat capacity (Cc) as called for in the appropriate section.10.3 Determine the thermal conductivity calibration factor, D.10.3.1 Weigh the thin (0.4 mm) polystyrene (or other) calibration disk (from 7.5.1); record the mass as m. Enter it as anexperimental parameter into the apparatu
49、s calculator. Encapsulate the thin polystyrene calibration disk in a standard aluminumsample container with lid.10.3.2 Place the encapsulated test specimen in the DSC on the specimen sensor. Use an empty aluminum container and lid onthe reference side.NOTE 5Matching the combined weights of the reference container and lid to those of the specimen container and lid within 60.1 mg produces thebest results.10.3.3 Measure the heat capacity of the thin polystyrene calibration material using the conditions of 10.2.1. Record the specifiche
