1、Designation: E1860 13 (Reapproved 2018)Standard Test Method forElapsed Time Calibration of Thermal Analyzers1This standard is issued under the fixed designation E1860; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 calibration or perfor-mance confirmation of the elapsed-time signal from thermalanalyzers.
3、1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 There is no ISO standard equivalent to this test method.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is ther
4、esponsibility 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.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard
5、-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D3350 Specification for Polyethylene Plastics Pip
6、e and Fit-tings MaterialsD3895 Test Method for Oxidative-Induction Time of Poly-olefins by Differential Scanning CalorimetryD4565 Test Methods for Physical and Environmental Per-formance Properties of Insulations and Jackets for Tele-communications Wire and CableD5483 Test Method for Oxidation Induc
7、tion Time of Lubri-cating Greases by Pressure Differential Scanning Calorim-etryE473 Terminology Relating to Thermal Analysis and Rhe-ologyE487 Test Method for Constant-Temperature Stability ofChemical MaterialsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test
8、 MethodE1142 Terminology Relating to Thermophysical PropertiesE1858 Test Methods for Determining Oxidation InductionTime of Hydrocarbons by Differential Scanning Calorim-etryE1868 Test Methods for Loss-On-Drying by Thermogravi-metryE2070 Test Methods for Kinetic Parameters by DifferentialScanning Ca
9、lorimetry Using Isothermal MethodsE2161 Terminology Relating to Performance Validation inThermal Analysis and Rheology3. Terminology3.1 Definitions:3.1.1 The technical terms used in this test method aredefined in Terminologies E473, E1142, and E2161, includingcalibration, conformance, relative stand
10、ard deviation, andthermal analysis.4. Summary of Test Method4.1 The elapsed time signal generated by a thermal analyzeris compared to a clock (or timer) whose performance is knownand traceable to a national metrology institute. The thermalanalyzer may be said to be in conformance, if the performance
11、of the thermal analyzer is within established limits.Alternatively, the elapsed time signal may be calibrated usinga two point calibration method.5. Significance and Use5.1 Most thermal analysis experiments are carried out underincreasing temperature conditions where temperature is theindependent pa
12、rameter. Some experiments, however, are car-ried out under isothermal temperature conditions where theelapsed time to an event is measured as the independentparameter. Isothermal Kinetics (Test Methods E2070), ThermalStability (Test Method E487), Oxidative Induction Time (OIT)(Test Methods D3895, D4
13、565, D5483, E1858, and Specifica-tion D3350) and Loss-on-Drying (Test Methods E1868) arecommon examples of these kinds of experiments.1This test method is under the jurisdiction ofASTM Committee E37 on ThermalMeasurements and is the direct responsibility of Subcommittee E37.10 onFundamental, Statist
14、ical and Mechanical Properties.Current edition approved Aug. 1, 2018. Published August 2018. Originallyapproved in 1997. Last previous edition approved in 2013 as E1860 13. DOI:10.1520/E1860-13R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a
15、t serviceastm.org. For Annual Book of ASTMStandards volume information, 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 StatesThis international standard was developed in accord
16、ance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15.2 Modern scientific instruments
17、, including thermalanalyzers, usually measure elapsed time with excellent preci-sion and accuracy. In such cases, it may only be necessary toconfirm the performance of the instrument by comparison to asuitable reference. Only rarely will it may be required tocorrect the calibration of an instruments
18、 elapsed time signalthrough the use of a calibration factor.5.3 It is necessary to obtain elapsed time signal conformityonly to 0.1 times the repeatability relative standard deviation(standard deviation divided by the mean value) expressed as apercent for the test method in which the thermal analyze
19、r is tobe used. For those test methods listed in Section 2 thisconformity is 0.1 %.6. Apparatus6.1 Timer or Stopwatch, with timing capacity of at least 3 h(10 800 s), a resolution of 0.1 s or better and an accuracy of1.5 s per day which performance has been verified usingstandards and procedures tra
20、ceable to a national metrologyinstitute (such as the National Institute of Standards andTechnology (NIST). Such timers are available from mostlaboratory equipment suppliers.7. Calibration7.1 Perform any elapsed time signal calibration proceduresrecommended by the manufacturer of the thermal analyzer
21、 asdescribed in the operators manual.8. Procedure8.1 Obtain the instrument reaction time (I).8.1.1 Reset the timer and the elapsed time signal for thethermal analyzer to zero elapsed time.8.1.2 Simultaneously start the timer and the elapsed timesignal for the thermal analyzer.Allow them to run for 6
22、 to 10 s.Simultaneously stop the timer and the elapsed time signal forthe thermal analyzer. Record the elapsed time from the timer ast1. Record the elapsed time from the thermal analyzer as t2.NOTE 1The elapsed time of the timer (t1) is equal to the elapsed timeof the thermal analyzer (t2) plus the
23、instrument reaction time (I). Theinstrument reaction time is that required for the thermal analyzer toinitialize and terminate the thermal analysis experiment and may be up toseveral seconds. The instrument start up time does not affect the elapsedtime of the thermal analysis experiment since the ex
24、periment is exclusiveof this time.NOTE 2Data acquisition rate shall be set to the maximum available.NOTE 3Time measurements shall be recorded in seconds retaining allavailable digits.8.1.3 Calculate the instrument reaction time I by Eq 2 (9.2).8.2 Obtain the calibration constant (S).8.2.1 Reset the
25、timer and the elapsed time signal for thethermal analyzer to zero elapsed time.8.2.2 Simultaneously start the timer and the elapsed timesignal for the thermal analyzer. Allow them to run for aminimum of 10 000 s (= 167 min = 2.8 h = 2 h, 47 min).Simultaneously stop the timer and the elapsed time sig
26、nal forthe thermal analyzer (see Note 2, Note 3, and Note 4). Recordthe elapsed time from the timer as tt. Record the elapsed timefrom the thermal analyzer as to.8.2.3 Calculate the value for S using Eq 3 (see 9.3).8.3 Using the values for I and S from 8.1.3 and 8.2.3,calculate the percent conformit
27、y (C) using Eq 4 or table ofpercent conformity values (see 9.4).9. Calculation9.1 For the purpose of these procedures, it is assumed thatthe relationship between observed elapsed time (to) and theactual elapsed time (t) is linear and is governed by Eq 1:t 5 toS (1)where:t = true experimental elapsed
28、 time (s),to= thermal analyzer observed elapsed time (s), andS = slope (nominal value = 1.00000).9.2 Using the values for t1and t2from 8.1, the instrumentreaction time (I) may be calculated by:I 5 t12 t2(2)9.3 Using the values for ttand tofrom 8.2, the calibrationconstant S may be calculated by:S 5
29、tt2 I!/to(3)where:tt= observed time of reference timer.9.3.1 When performing this calculation, retain all availabledecimal places in the measured value and in the value of S.9.4 Using the value for S from 9.3, the percent conformityof the instrument elapsed time indicator may be calculated asfollows
30、:C 5 1.00000 2 S! 3100% (4)NOTE 4The percent conformity is usually a very small number andexpressing it as a percent value may be inconsistent with SI metricnotation. Because of its effect on the experiment and because of commonuse, it is expressed as a percent is this procedure.9.4.1 Conformity may
31、 be estimated to one significant figureusing the following criteria:9.4.1.1 If S lies:Between 0.9999 and 1.0001, then conformity is better than 0.01 %,Between 0.9990 and 0.9999 or between 1.0001 and 1.0010, then conformity isbetter than 0.1 %, andBetween 0.9900 and 0.9990 or between 1.0010 and 1.010
32、0, then conformity isbetter than 1 %.9.5 Using the determined value for S, Eq 1 may be used tocalculate the true elapsed time (t) from an observed elapsedtime (to).10. Report10.1 Report the following information:10.1.1 Model number and description of the thermal ana-lyzer used,10.1.2 The value of S
33、as determined in 8.2.3 reported to atleast five places to the right of the decimal point, and10.1.3 Conformity as determined in 9.4.E1860 13 (2018)211. Precision and Bias11.1 An interlaboratory study of elapsed time calibrationwas conducted in 1996 that included participation by ninelaboratories usi
34、ng instruments from four manufacturers. Theresults were treated by Practice E691.311.2 Precision:11.2.1 The mean value for the calibration constant wasS = 0.999853.11.2.2 The repeatability (within laboratory) standard devia-tion for S was 0.000034.11.2.2.1 Two values, each the mean of duplicate dete
35、rmina-tions within a single laboratory should be considered suspect ifthey differ by more than the 95 % repeatability limitr = 0.000095.11.2.3 The reproducibility (between laboratory) standarddeviation for S was 0.00024.11.2.3.1 Two values, each the mean of duplicate determina-tions in differing lab
36、oratories, should be considered suspect, ifthey differ by more than the 95 % reproducibility limitR = 0.00069.11.3 Bias:11.3.1 The measurement of conformity in this test method isa comparison of the calibration constant S with the theoreticalvalue of 1.000000 and provides an indication of bias.11.3.
37、2 The mean value for conformity was C = 0.015 %.11.3.3 Conformity was found to vary widely among instru-ment models but in no case exceeded C = 0.05 %. This value isfar better than the nominal conformity of 1 % required for mostthermal analysis experiments.12. Keywords12.1 calibration; elapsed time;
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41、own to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting AS
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