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1、 Reference number ISO 22007-4:2008(E) ISO 2008 INTERNATIONAL STANDARD ISO 22007-4 First edition 2008-12-15 Plastics Determination of thermal conductivity and thermal diffusivity Part 4: Laser flash method Plastiques Dtermination de la conductivit thermique et de la diffusivit thermique Partie 4: Mth
2、ode flash laser Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) PDF disclaimer This PDF file
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5、ation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2
6、008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the co
7、untry of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reserved Copyright International Organization for Standardization Provided by IHS under
8、license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) ISO 2008 All rights reserved iii Contents Page Foreword iv 1 Scope 1 2 Normative references1 3 Terms and definitions .1 4 P
9、rinciple2 5 Apparatus .2 5.1 General2 5.2 Furnace or climatic chamber2 5.3 Flash source.4 5.4 Transient detectors4 5.5 Thickness measurement device.5 6 Test specimen5 6.1 Shape and dimension of the specimen.5 6.2 Preparation and conditioning of test specimen.5 6.3 Coating the specimen .5 7 Calibrati
10、on and verification 6 7.1 Calibration of apparatus .6 7.2 Verification of apparatus.6 8 Procedure .6 9 Data analysis7 10 Uncertainty.9 11 Test report9 Annex A (informative) Correction for finite pulse duration.10 Annex B (informative) Alternative methods of calculating thermal diffusivity.11 Bibliog
11、raphy12 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) iv ISO 2008 All rights reserved Fore
12、word ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a techn
13、ical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
14、electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to
15、 the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for
16、identifying any or all such patent rights. ISO 22007-4 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical- chemical properties. ISO 22007 consists of the following parts, under the general title Plastics Determination of thermal conductivity and thermal diffusivity:
17、 Part 1: General principles Part 2: Transient plane heat source (hot disc) method Part 3: Temperature wave analysis method Part 4: Laser flash method Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/20
18、09 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 22007-4:2008(E) ISO 2008 All rights reserved 1 Plastics Determination of thermal conductivity and thermal diffusivity Part 4: Laser flash method 1 Scope 1.1 This part of ISO 22007 specifi
19、es a method for the determination of the thermal diffusivity of a thin solid disc of plastics in the thickness direction by the laser flash method. This method is based upon the measurement of the temperature rise at the rear face of the thin-disc specimen produced by a short energy pulse on the fro
20、nt face. 1.2 The method can be used for homogeneous solid plastics as well as composites having an isotropic or orthotropic structure. In general, it covers materials having a thermal diffusivity, , in the range 1 107 m2s1 m1 0,27: F(m1) = 0,085 48 0,314(0,548 6 m1) + 0,500(0,548 6 m1)2,63 (5) For m
21、1 0,44: F(m1) = 0,081 9 + 0,305m1 (6) NOTE 2 Values of m1 less than 0,27 should not be obtained as they do not have any physical significance. This calculation method can be used if the following conditions are satisfied: the duration of the laser pulse is short compared with the time characteristic
22、 for thermal diffusion (i.e. pulse width 1 % of t1/2) or, if not, a correction is applied to the time scale in accordance with Annex A; the front face of the specimen is uniformly heated by the laser pulse; the specimen is homogeneous; the specimen is opaque to the laser radiation at the wavelength
23、used. NOTE 3 The potential effect of non-uniformity of the pulse on the calculated thermal diffusivity can usually be assumed to be negligible due to the use of an IR detector to detect the transient temperature rise of the specimen rear face. However, if needed, the laser beam could be made more un
24、iform by using beam-homogenizing optics. NOTE 4 The assumption of opacity of the specimen is implicitly satisfied by the deposit of an appropriate coating on its two faces. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 N
25、ot for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) ISO 2008 All rights reserved 9 10 Uncertainty The relative expanded uncertainty (confidence level of 95 %) of the thermal-diffusivity determination by the laser flash meth
26、od with the partial time moments method is estimated to be from 3 % to 5 % 6 between ambient temperature and 400 C (depending on the material and the temperature). It has been calculated in accordance with the ISO/IEC Guide 98-3. On the basis of the results of five successive measurements performed
27、under the same conditions, the repeatability of the method is better than 1 %. 11 Test report The test report shall include the following information: a) a reference to this part of ISO 22007; b) the date of the test; c) all details necessary for complete identification of the sample tested (type, b
28、atch number, etc.), including its thermal history; d) the shape and dimensions (diameter and thicknesses at room temperature and at each test temperature, giving the method of calculation of the thicknesses at the test temperatures) of the specimens and the number of specimens tested; e) details of
29、sample and specimen preparation; f) whether a coating was used and, if so, the coating material and coating procedure and the thickness of the coating); g) the wavelength and duration of the laser pulse; h) the type of detector used for measuring the transient temperature rise of the specimen rear f
30、ace; i) the type of furnace used and its temperature range (or a statement to the effect that a climatic chamber was used); j) the measurement conditions, such as the test temperature(s), in degrees Celsius, and the furnace atmosphere; k) the method(s) used to calculate the thermal diffusivity and e
31、stimate corrections (e.g. due to heat losses and the finite pulse duration); l) the thermal-diffusivity value(s) obtained, in square metres per second; m) any additional information or details of operations not specified in this part of ISO 22007, which may be important for assessment of the results
32、. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) 10 ISO 2008 All rights reserved Annex A (i
33、nformative) Correction for finite pulse duration All the methods used to calculate thermal diffusivity assume that the laser pulse is similar to a Dirac function. However, if the duration of the pulse cannot be neglected (see Clause 9), the effect of the finite pulse time should be corrected for. Fo
34、r the methods of calculation based on the use of the half-rise time, t1/2, a first approach consists in calculating the thermal diffusivity, assuming a Dirac function pulse, and applying a correction to the value obtained. By specifying the shapes of pulses, several authors 7,8,9 have proposed analy
35、tical relationships to estimate this correction. A more general method consists in shifting the time origin to the centroid, tg, of the laser pulse and calculating the thermal diffusivity considering the pulse as a Dirac function. In this case, the waveform of the laser pulse is measured by a detect
36、or having a response faster than 10 s and the position of the centroid is calculated directly from the observed waveform. This method, proposed initially by Azumi and Takahashi 10 for adiabatic experiments, has been extended to non-adiabatic ones by Degiovanni 11. Copyright International Organizatio
37、n for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license from IHS -,-,- ISO 22007-4:2008(E) ISO 2008 All rights reserved 11 Annex B (informative) Alternative methods of ca
38、lculating thermal diffusivity All methods of calulating thermal diffusivity are based on the mathematical solution of the heat conduction equation with appropriate initial and boundary conditions. The original method proposed by Parker et al. 12 is based on an analytical model corresponding to an ad
39、iabatic experiment, on the basis of which the thermal diffusivity is calculated from the half-rise time, t1/2. In the case of an adiabatic experiment, the thermal diffusivity is calculated simply from the thickness, d, and the half-rise time, t1/2, as follows: 2 1/2 0,13879 d t = (B.1) The use of th
40、is method, which neglects heat losses, can generate significant systematic errors in thermal- diffusivity determinations. It is not a suitable method for polymers because of their low thermal diffusivity and the test cannot really be considered adiabatic. Some methods are based on an improvement of
41、Parkers method, introducing correction factors in the calculation of the thermal diffusivity to take into account the unavoidable heat losses. They use one or several characteristic points on the experimental curve. Among them, Cape and Lehmans method 13, Cowans method 14 and Clark and Taylors metho
42、d 15 are the most commonly used. With the advances in modern data acquisition, methods based on the analysis of a part (i.e. the partial time moments method of Degiovanni and Laurent 5) or the whole of the temperature response (i.e. the technique proposed by Gembarovic et al. 16 using a least-square
43、s method) are increasingly utilized. These calculation methods are generally based on minimizing the difference between the measured values and the theoretical values obtained from a mathematical model. They differ either by the analytical model used or by the way in which they compare the measured
44、experimental temperature rise versus time recordings with the analytical curve. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Boeing Co/5910770001 Not for Resale, 01/31/2009 04:40:11 MSTNo reproduction or networking permitted without license
45、 from IHS -,-,- ISO 22007-4:2008(E) 12 ISO 2008 All rights reserved Bibliography 1 ISO 18755, Fine ceramics (advanced ceramics, advanced technical ceramics) Determination of thermal diffusivity of monolithic ceramics by laser flash method 2 SALMON, D., BAXENDALE, S., GROBOTH, G., HAY, B., HAMMERSCHM
46、IDT, U., BRANDT, R., SINNEMA, S. and BAILLIS, D.: The certification of thermal conductivity and diffusivity properties of Pyroceram 9606 as a reference material up to 1 000 C, HTCRM, Certification Report (2003) 3 http:/www.irmm.jrc.be 4 AKOSHIMA, M. and BABA, T.: Thermal Diffusivity Measurements of
47、Candidate Reference Materials by the Laser Flash Method, Int. J. of Thermophysics, 26 (1), pp. 151-163 (2005) 5 DEGIOVANNI, A. and LAURENT, M.: Une nouvelle technique didentification de la diffusivit thermique par mthode flash, Rev. Phys. Appl., 21, pp. 229-237 (1986) 6 HAY, B., FILTZ, J.-R., HAMEUR
48、Y, J. and RONGIONE, L.: Uncertainty of Thermal Diffusivity Measurements by Laser Flash Method, Int. J. of Thermophysics, 26 (6), pp. 1883-1898 (2005) 7 HECKMAN, R.C.: Finite pulse-time and heat-loss effects in pulse thermal diffusivity measurements, J. Appl. Phys., 44 (4), pp. 1455-1460 (1973) 8 LARSON, K.B. and KOYAMA, K.: Correction for finite-pulse-time effects in very thin samples us