1、Designation: E967 18Standard Test Method forTemperature Calibration of Differential ScanningCalorimeters and Differential Thermal Analyzers1This standard is issued under the fixed designation E967; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e 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. Scope1.1 This test method describes the temperature calibrationof differential thermal analyzers and
3、 differential scanningcalorimeters over the temperature range from 40Cto +2000C.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This test method is similar to ISO standard 113571.1.4 This standard does not purport to add
4、ress all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific precautionary statements are gi
5、ven in Section 7.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization Tec
6、hnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E473 Terminology Relating to Thermal Analysis and Rhe-ologyE1142 Terminology Relating to Thermophysical Properties2.2 ISO Standards:3113571 Plastics-Differential Scanning Calorimetry (DSC)-Part 1: General Principles3.
7、 Terminology3.1 DefinitionsSpecific technical terms used in this testmethod are defined in Terminologies E473 and E1142.4. Summary of Test Method4.1 This test method consists of heating the calibrationmaterials at a controlled rate in a controlled atmospherethrough a region of known thermal transiti
8、on. The heat flowinto the calibration material or the difference of temperaturebetween the calibration material and a reference sample ismonitored and continuously recorded. A transition is markedby the absorption of energy by the specimen resulting in acorresponding endothermic peak in the heating
9、curve.NOTE 1Heat flow calibrations are sometimes determined in conjunc-tion with temperature calibration. Some differential scanning calorimeterspermit both heat flow and temperature calibrations to be obtained from thesame experimental procedure.5. Significance and Use5.1 Differential scanning calo
10、rimeters and differential ther-mal analyzers are used to determine the transition temperaturesof materials. For this information to be meaningful in anabsolute sense, temperature calibration of the apparatus andcomparison of the resulting data to that of known standardmaterials is required.5.2 This
11、test method is useful in calibrating the temperatureaxis of differential scanning calorimeters and differential ther-mal analyzers.6. Apparatus6.1 Apparatus shall be of either type listed below:6.1.1 Differential Scanning Calorimeter (DSC), capable ofheating a test specimen and a reference material
12、at a controlledrate and of automatically recording the differential heat flowbetween the sample and the reference material to the requiredsensitivity and precision.6.1.1.1 A Furnace(s), to provide uniform controlled heatingor cooling of a specimen and reference to a constant tempera-ture or at a con
13、stant rate within the applicable temperaturerange of this test method.6.1.1.2 A Temperature Sensor, to provide an indication ofthe specimen temperature.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.01 on C
14、alo-rimetry and Mass Loss.Current edition approved March 15, 2018. Published March 2018. Originallyapproved in 1983. Last previous edition approved in 2014 as E967 08 (2014).DOI: 10.1520/E0967-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、 serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Standardization (ISO), 1, ch. dela Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.Copyright AST
16、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Stan
17、dards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.16.1.1.3 Differential Sensors, to detect a heat flow (power)difference between the specimen and reference.6.1.1.4 Test Chamber Environment, a means of sustaining atest chamber environ
18、ment of nitrogen or other inert purge gasat a purge rate of 10 to 50 mL/min.6.1.1.5 A Temperature Controller, capable of executing aspecific temperature program by operating the furnace(s)between selected temperature limits at a rate of temperaturechange of 10C/min.6.1.1.6 Data Collection Device, to
19、 provide a means ofacquiring, storing, and displaying measured or calculatedsignals, or both. The minimum output signals required for DSCare heat flow, temperature, and time.6.1.2 Differential Thermal Analyzer (DTA), capable of heat-ing a test specimen and reference material at a controlled rateand
20、of automatically recording the differential temperaturebetween sample and reference material both to the requiredsensitivity and precision.6.2 Containers (pans, crucibles, vials, lids, closures, seals,etc.), that are inert to the specimen and reference materials andthat are of suitable structural sh
21、ape and integrity to contain thespecimen and reference in accordance with the specific require-ments of this test method.6.3 Nitrogen, or other inert purge gas supply.6.4 A Balance, to weigh specimens or containers (pans,crucibles, vials, etc.), or both to 60.1 mg. The balance shouldhave a capacity
22、greater than 20 mg.7. Precautions7.1 Toxic or corrosive effluents, or both, may be releasedwhen heating some material and could be harmful to personneland to apparatus.7.2 This test method assumes linear temperature indication.Care must be taken in the application of this test method toensure that c
23、alibration points are taken sufficiently closetogether so that linear temperature indication may be approxi-mated. Linear temperature indications means that there exists alinear, or first order, dependence on the temperature determinedby the instruments temperature sensor on the true temperatureof t
24、he sample material in its container and that this relation isadequately expressed by Eq 1.8. Calibration Materials8.1 For the temperature range covered by manyapplications, the melting transition of 99.99 % pure materialsin Table 1 may be used for calibration.9. Procedure9.1 Two Point Calibration:9.
25、1.1 Select two calibration materials from Table 1, withmelting temperatures one above and one below the temperaturerange of interest. The calibration materials should be as closeto the temperature range of interest as practical.9.1.2 Determine the apparent transition temperature foreach calibration
26、material.9.1.2.1 Into a clean specimen holder, placea5mgto15mgweighed amount of calibration material. Other specimenmasses may be used but must be indicated in the report.9.1.2.2 Load the specimen into the instrument chamber,purge the chamber with dry nitrogen (or other inert gas) at aflow rate of 1
27、0 to 50 mL/min throughout the experiment.9.1.2.3 Heat (or cool) the calibration material rapidly to30C below the calibration temperature and allow to stabilize.9.1.2.4 Heat the calibration material at 10C/min throughthe transition until baseline is reestablished above the transi-tion. Other heating
28、rates may be used but must be noted in thereport. Record the resulting thermal curve.NOTE 2Temperature scale calibration may be affected by temperaturescan rate, specimen holder, purge gas and purge gas flow rate. Thetemperature calibration shall be made under the same conditions used fortest specim
29、ens.9.1.2.5 From the resultant curve, measure the temperaturesfor the desired points on the curve, Te, Tp(see Fig. 1) retainingall available decimal places.where:Te= extrapolated onset temperature for fusion, C, andTp= melting peak temperature, C.TABLE 1 Melting Temperature of Calibration MaterialNO
30、TE 1The values in Table 1 were determined under special, highlyaccurate steady state conditions that are not attainable or applicable tothermal analysis techniques. The actual precision of this test method isgiven in Section 12 of this test method.Calibration MaterialMelting TemperatureA(C) (K)Mercu
31、ry 38.834 234.316Water 0.01B273.16Cyclohexane 6.71C279.86Phenoxybenzene 26.87 300.02Gallium 29.765B302.915Benzoic Acid 122.37 395.52Indium 156.5985D429.7485TinE231.928B,D505.078Bismuth 271.402D544.552Cadmium 321.069D594.219Lead 327.462D600.612Zinc 419.527B,D692.677Antimony 630.628D903.778Aluminum 66
32、0.323D933.473Silver 961.78B,D1234.93Gold 1064.18B,D1337.33Copper 1084.62B1357.77Nickel 1455D1728Cobalt 1494D1767Palladium 1554D1827Platinum 1772 2045Rhodium 1963 2236ARossini, F. D., Pure Applied Chemistry, Vol 22, 1970, p. 557.BThe melting temperatures of these materials have been selected as prima
33、ry fixedpoints for the International Practical Temperature Scale of 1990. See Mangum, B.W., and Furukawa, G. T., Guidelines for Realizing the International PracticalTemperature Scale of 1990 (ITS-90), NIST Technical Note 1265.CShimizu, Y., Ohte, Y., and Kato, K., “Certified Reference Material NMIJ C
34、RM5401-a,” Thermochimica Acta, Vol 568, 2013, pp. 6166.DUpdated melting temperatures were taken from Boettinger, W. J., Kattner, U. R.,Moon, K.-W., and Perepezko, J.H., DTAand Heat-flux DSC Measurements ofAlloyMelting and Freezing, NIST Special Publication 960-15, November 2006.ESome materials have
35、different crystalline forms (for example, tin) or may reactwith the container. These calibration materials should be discarded after their initialmelt.E967 182NOTE 3The actual temperature displayed on the temperature axisdiffers depending upon the instrument type; for example, sampletemperature, pro
36、gram temperature, sample program temperature average.Follow the instructions of the particular instrument manufacturer to obtainsample temperature at the point of interest.NOTE 4The available precision of the temperature measurementsdepends upon instrument capabilities and the temperature range of t
37、hetest. Below 300C, measurements to 60.5C are common while at greaterthan 700C 6 2C is reasonable.NOTE 5For high-purity crystalline materials (not polymers), Teistaken as the transition temperature when measured by differential scan-ning calorimeters and other instruments where the test specimen is
38、not inintimate contact with the temperature sensor. For instruments in which thetemperature sensor is in intimate contact with the sample, (such as somedifferential thermal analyzers), Tpis taken as the transition temperature.9.1.3 Using the apparent transition temperatures thusobtained, calculate t
39、he slope (S) and intercept (I)ofthecalibration Eq 1 (see Section 10). The slope and interceptvalues reported should be mean values from duplicate deter-minations based on separate specimens.9.2 One-Point Calibration:9.2.1 If the slope value (S) previously has been determinedin 9.1 (using the two-poi
40、nt calibration calculation in 10.2)tobesufficiently close to 1.0000, a one-point calibration proceduremay be used.NOTE 6If the slope value differs by only 1 % from unity (that is, S 1.0100), a 1C error will be produced if the test temperaturediffers by 100C from the calibration temperature.9.2.2 Sel
41、ect a calibration material from Table 1. The cali-bration temperature should be centered as close as practicalwithin the temperature range of interest.9.2.3 Determine the apparent transition temperatures of thecalibration material using steps 9.1.2.1 9.1.2.5.9.2.4 Using the apparent transition tempe
42、rature thusobtained, calculate the intercept (I) of the calibration equationusing all available decimal places. The value reported shouldbe a mean value based upon duplicate determinations onseparate specimens.9.3 If practical, adjustment to the temperature scale of theinstrument should be made so t
43、hat temperatures are accuratelyindicated directly.10. Calculations10.1 For the purposes of this procedure, it is assumed thatthe relationship between observed temperature (TO) and actualspecimen temperature (T) is a linear one governed by thefollowing equation:T 5 TO 3 S!1I (1)where:S and I = the sl
44、ope and intercept, respectively. (See 10.2 forthe values for S and I, used in Eq 1.)NOTE 7For some instruments, the assumption of a linear relationbetween observed and actual specimen temperature may not hold. Undersuch conditions, calibration temperatures sufficiently close together shallbe used so
45、 that the instrument calibration is achieved with a series of linearrelations.10.2 Two-Point Calibration:10.2.1 Using the standard temperature values taken fromTable 1 and the corresponding observed temperatures takenfrom experimental 9.1.2.5, calculate the slope and interceptusing the following equ
46、ations:S 5 TS12 TS2!/TO12 TO2! (2)I 5 TO13 TS2! 2 TS13 TO2!#/TO12 TO2! (3)where:S = slope (nominal value = 1.00),I = intercept,FIG. 1 Reference Material Melting EndothermE967 183TS1= reference transition temperature for standard 1 takenfrom Table 1,TS2= reference transition temperature for standard
47、2 takenfrom Table 1,TO1= observed transition temperature for standard 1 deter-mined in Section 9, andTO2= observed transition temperature for standard 2 ob-served in Section 9.NOTE 8I has the same units (that is, C or K) as TS1, TS2, TO1andTO2which are consistent with each other. The value for I wil
48、l be differentdepending upon the units used. S is a dimensionless number whose valueis independent of the units of I and T.10.2.2 S should be calculated to four significant figures andI should be calculated retaining all available decimal places.10.3 One-Point CalibrationIf the slope value determine
49、dabove is sufficiently close to 1.000, only the intercept need bedetermined through a one-point calibration procedure.I 5 TS12 TO1(4)10.4 Using the determined values for S and I, Eq 1 may beused to calculate the actual specimen transition temperature (T)from an observed transition temperature (TO). Values of T maybe rounded to the nearest 0.1C.11. Report11.1 The report shall include the following:11.1.1 Complete identification and description of the refer-ence materials used including source and purity,11.1.2 Description of the instrument
