ASTM E1363-2003 Standard Test Method for Temperature Calibration of Thermomechanical Analyzers《热机械分析仪温度校准的标准试验方法》.pdf

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1、Designation: E 1363 03Standard Test Method forTemperature Calibration of Thermomechanical Analyzers1This standard is issued under the fixed designation E 1363; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisi

2、on. 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 describes the temperature calibrationof thermomechanical analyzers from 50 to 1100C. (SeeNote 2.)1.2 Computer o

3、r electronic based instruments, techniques,or data treatment equivalent to this test method may be used.NOTE 1Users of this test method are advised that all such instrumentsor techniques may not be equivalent. It is the responsibility of the user ofthis test method to determine the necessary equival

4、ency prior to use.1.3 SI units are the standard.1.4 This standard is similar to ISO 113591 but addresses alarger temperature range and utilizes additional calibrationmaterials.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsib

5、ility 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. Specific precau-tionary statements are given in Section 7 and Note 10.2. Referenced Documents2.1 ASTM Standards:E 473 Terminology Relating

6、 to Thermal Analysis22.2113591 Thermomechanical Analysis (TMA)-Part 1: Gen-eral Principles33. Terminology3.1 Definitions:3.1.1 The terminology relating to thermal analysis appear-ing in E 473 shall be considered applicable to this document.4. Summary of Test Method4.1 An equation is developed for th

7、e linear correlation of theexperimentally observed program temperature and the actualmelting temperature for known melting standards. This isaccomplished through the use of a thermomechanical analyzerwith a penetration probe to obtain the onset temperatures fortwo melting point standards. An alterna

8、te, one-point method oftemperature calibration, is also given for use over very narrowtemperature ranges. (See Note 3.)NOTE 2This test method may be used for calibrating thermomechani-cal analyzers at temperatures outside this range of temperature. However,the accuracy of the calibration will be no

9、better than that of thetemperature standards used.NOTE 3It is possible to develop a more elaborate method of tempera-ture calibration using multiple (more than two) fusion standards andquadratic regression analysis. Since most modern instruments are capableof heating rates which are essentially line

10、ar in the region of use, theprocedure given here is limited to a two-point calibration.5. Significance and Use5.1 Thermomechanical analyzers are employed in theirvarious modes of operation (penetration, expansion, flexure,etc.) to characterize a wide range of materials. In most cases,the value to be

11、 assigned in thermomechanical measurements isthe temperature of the transition (or event) under study.Therefore, the temperature axis (abscissa) of all TMA thermalcurves must be accurately calibrated either by direct reading ofa thermocouple or by adjusting the programmer temperature tomatch the act

12、ual temperature over the temperature range ofinterest.6. Apparatus6.1 Thermomechanical Analyzer (TMA), The essential in-strumentation required to provide the minimum thermome-chanical analytical or thermodilatometric capability for thismethod includes:6.1.1 A Rigid Specimen Holder or Platform, of in

13、ert, lowexpansivity material ( 1 m m-1K-1) to center the specimen inthe furnace and to fix the specimen to mechanical ground.6.1.2 A Rigid (expansion compression, flexure, tensile, etc)Probe, of inert, low expansivity material ( 1 m m-1K-1) thatcontacts with the specimen with an applied compressive

14、ortensile force. For this test method the use of a penetration probeis recommended.1This test method is under the jurisdiction of ASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on TestMethods and Recommended Practices.Current edition approved March

15、10, 2003. Published April 2003. Originallyapproved in 19 90. Last previous edition approved in 1997 as E 1363 97.2Annual Book of ASTM Standards, Vol 14.02.3Available from American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harb

16、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.3 A Sensing Elementlinear over a minimum range of2 mm to measure the displacement of the rigid probe to 6 50nm resulting from changes in the length/height of the speci-men.6.1.4 A Weight or Force Transducer, to generate a con

17、stantforce of 50 6 5 mN (5.0 6 0.5 g) that is applied through therigid probe to the specimen.NOTE 4The recommendation of a 5.0 g load (or a force of 50 mN) isbased on the use of penetration probes commonly used in the commer-cially available thermomechanical analyzers. These probes have tipdiameters

18、 ranging from 0.89 to 2.0 mm and lead to pressures from 80 to16 kPa when using the recommended 5.0 g load. The use of probes whichdiffer greatly from this range of tip diameters may require differentloading (or force).6.1.5 A Furnace, capable of providing uniform controlledheating (cooling) at a rat

19、e of 10 6 1 C min-1of a specimen toa constant temperature within the applicable temperature rangeof this methodNOTE 5The temperature range of operation of commercial thermo-mechanical analyzers vary by manufacturer and mode. The completerange of temperature of an instrument is sometimes achieved by

20、the use oftwo different furnaces. In this case, temperature calibration must becarried out for each furnace.6.1.6 A Temperature Controller, capable of executing aspecific temperature program by operating the furnace betweenselected temperature limits at a rate of temperature change of10 6 1 C min-1.

21、6.1.7 A Temperature Sensor, that may be positioned in closeproximity to the test specimen to provide an indication of thespecimen/furnace temperature to within 6 0.1 C min6.1.8 A means of sustaining an environment around thespecimen with an inert purge gas (e.g., nitrogen, helium, argon,etc.) at a p

22、urge gas flow rate of 20 to 50 mL min-1.6.1.9 A Recording Device, capable of recording any display-ing fraction (including noise) of the specimen dimension signal(TMA curve) on the Y-axis versus any fraction (includingnoise) temperature of the X-axis.7. Hazards7.1 This test method may involve the us

23、e of hazardousmaterials, operations, and equipment. It is the responsibility ofthe user of this test method to establish appropriate safetypractice and to determine the applicability of regulatorylimitations prior to use.NOTE 6Warning: Toxic or corrosive effluents, or both, may bereleased when heati

24、ng some materials and could be harmful to personneland the apparatus.7.2 Once this calibration procedure has been executed asdescribed in 10.1.2.1-10.1.2.8 of this test method, the measur-ing thermocouple position should not be changed, nor should itbe in contact with the sample or sample holder in

25、a way thatwould impede movement. If for some reason the thermocoupleposition is changed or the thermocouple is replaced, then theentire calibration procedure should be repeated.8. Calibration8.1 For the temperature range covered by many applica-tions, the melting transition of 99.99 % pure materials

26、 may beused for calibration. (See Table 1.)NOTE 7The melting temperatures of these materials have beenselected as primary fixed points (see Table 1) for the InternationalPractical Temperature Scale of 1990.4NOTE 8Some materials have different crystalline forms (for example,tin) or may react with the

27、 container. Such calibration materials should bediscarded after their initial melt.9. Assignment of the Penetration Onset Temperature9.1 The assignment of the TMA penetration onset tempera-ture is an important procedure since, when using this method,temperature calibration of the thermomechanical an

28、alyzer isdirectly dependent upon it. The temperature standards given inTable 1 will give a downward deflection on the thermal curve,similar to that shown in Fig. 1, when placed under a weightedTMA penetration probe and heated to their respective meltingtemperatures.9.2 The extrapolated onset tempera

29、ture for such a penetra-tion thermal curve is obtained by extending the pretransitionportion of the thermal curve to the point of intersection with aline drawn tangent to the steepest portion of the curve which4Supporting data are available from ASTM Headquarters. Request RR:E37-1011.TABLE 1 Recomme

30、nded Melting Temperature StandardsACalibration MaterialBMelting Temperature(C) (K)Mercury 38.8344 234.3156Water 0.01 273.16Gallium 29.7646 302.9146Indium 156.5985 429.7485Tin 231.928 505.078Zinc 419.527 692.677Aluminum 660.323 933.473Silver 961.78 1234.93Gold 1064.18 1337.33Copper 1084.62 1357.77ATh

31、e values in Table 1 were determined using special, 99.9999 % purematerials, and highly accurate steady state conditions that are not attainable orapplicable to thermal analysis techniques. The actual precision of this test methodis given in Section 12.BB. W. Mangnum and G. T. Furukawa, “Guidelines f

32、or Realizing the Interna-tional Temperature Scale of 1990 (ITS-90),” National Institute of Standards andTechnology Technical Note 1265, page 8, 1990.FIG. 1 Assignment of the Extrapolated Onset Temperature (To)from TMA Thermal CurveE1363032describes the probe displacement. The temperature correspond-

33、ing to this point of intersection is the penetration onsettemperature. This is shown graphically in Fig. 1. There aresome materials (for example, aluminum metal) which showpretransition probe displacement prior to the sharper down-ward deflection observed on melting. In this case, the pretran-sition

34、 baseline is extended from the point which represents thehighest temperature the material reaches prior to exhibitingsignificant or measurable softening under the conditions of theexperiment. Fig. 2 describes the assignment of the extrapolatedonset temperature for a specimen which exhibits pretransi

35、tionpenetration.10. Procedure10.1 Two-Point CalibrationFor the purposes of this pro-cedure, it is assumed that the relationship between observedextrapolated onset temperature (To) and actual specimen tem-perature (Tt) is a linear one governed by the equation:Tt5 To3 S! 1 I (1)where: S and I are the

36、slope and intercept of a straight line,respectively.10.1.1 Select two calibration standards near the temperaturerange of interest. The standards should be as close to the upperand lower temperature limits used in the actual analysis runs asis practical.10.1.2 Determine the apparent extrapolated onse

37、t tempera-ture for the calibration material chosen, using a penetration-type probe with the TMA instrument.10.1.2.1 Place a 10 to 20-mg specimen of one of thecalibration standards on the sample platform (or holder, which-ever is applicable). The specimen should have a smooth surfaceon both top and b

38、ottom. Avoid the use of specimens with sharpridges and irregular surfaces. These can lead to false values forthe onset temperatures. Powdered or liquid standards may beplaced into a stable, inert container, if necessary.10.1.2.2 Place a probe loaded with 5 g (or force of 50 mN)in contact with the te

39、st specimen.10.1.2.3 Purge the sample chamber area with inert gas at aflow rate that is appropriate to the dimensions of the apparatusthroughout the experiment. Typical flow rates are from 20 to 50mL/min. The same purge gas and flow rate should be main-tained in both calibration runs and analyses ru

40、ns.10.1.2.4 Select the appropriate sensitivity for the ordinate(penetration) scale so that the observed sample penetration is atleast 40 % of the full-scale deflection value.10.1.2.5 Heat the calibration sample specimen to a tempera-ture about 50C below the calibration temperature and allowthe TMA f

41、urnace to equilibrate.10.1.2.6 Heat the calibration sample specimen through thetransition allowing the probe to reach a point of maximumpenetration. (See Fig. 1.)NOTE 9Temperature calibration may be affected by heating rate,purge gas flow rate, and choice of purge gas.10.1.2.7 From the TMA thermal c

42、urve obtained, assign theextrapolated onset temperature (see Fig. 1) to the requiredprecision.NOTE 10When recording directly, retain all digits known, plus onedigit that may be uncertain due to estimation. When data are obtained froma digital display or printout from the instrument, retain all avail

43、able digits.10.1.2.8 Repeat the procedure described in 10.1.2-10.1.2.6using the second calibration standard that was chosen.11. Calculation11.1 Using the standard temperature values from Table 1and the corresponding onset temperatures obtained experimen-tally, calculate the slope and intercept using

44、 the followingequations:S 5 Ta12 Ta2#/T012 T02# (2)I 5 T013 Ta2! 2 Ta13 T02!#/T012 T02! (3)where:S = slope (nominal value = 1.00),I = intercept,Ta1= reference transition temperature for Standard 1 takenfrom Table 1,Ta2= reference transition temperature for Standard 2 takenfrom Table 1,T01= experimen

45、tally observed transition onset tempera-ture for Standard 1, andT02= experimentally observed transition onset tempera-ture for Standard 2.NOTE 11Caution: The slope S is a dimensionless number whosevalue is independent of which temperature scale is used for I and T. I,inall cases, must have the same

46、units as Ta1, Ta2, T01and T02that are bynecessity consistent with each other.11.2 S should be calculated to 60.01 units while I shouldbe calculated to 60.1C.NOTE 12This is the minimum acceptable precision to the intermedi-ately calculated parameters. If calculation is performed using a digitalcalcul

47、ator or computer, retain all available digits without rounding.Rounding is performed only in reporting the final result in 11.3 or 11.4.2.11.3 Using the determined values for S and I, Eq 1 may beused to calculate the actual specimen transition, Tt, from anyexperimentally observed transition temperat

48、ure, T0, for theparticular TMA instrument employed.NOTE 13The final result is rounded to the nearest 0.1C consistentFIG. 2 Assignment of Extrapolated Onset Temperature (To) fromTMA Thermal Curve for Specimen Exhibiting PretransitionSofteningE1363033with the repeatability standard deviation reported

49、in 13.2.1.11.4 One-Point Calibration:11.4.1 In this abbreviated procedure, a relationship betweenthe extrapolated onset temperature as observed from the use ofa weighted penetration probe with one of the metal calibrationstandards (see Table 1) and the temperature as assigned by athermocouple is established. The operator should choose acalibration standard that is near the temperature of the transi-tion or phenomenon under study. For example, if one wereinterested in assigning the glass transition temperature of apolycarbonate specimen (Tg 150C),