ASTM E2069-19

This document is not an ASTM 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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2069 − 06 (Reapproved 2018) E2069 − 19
Standard Test Method for
Temperature Calibration on Cooling of Differential Scanning
Calorimeters
This standard is issued under the fixed designation E2069; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method coversdescribes the temperature calibration of differential scanning calorimeters (DSCs) on cooling using
the difference between transition temperatures upon heating and cooling in the temperature range of 50 to 185°C. 65 °C to 420
°C. An offset in the indicated temperature between heating and cooling experiments, within this temperature range, may be used
to provide temperature calibration on cooling at other temperature ranges.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 Test Method E3142 is an alternative to this test method.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. Specific precautionary statements are given in Section 6.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D3418 Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential
Scanning Calorimetry
E473 Terminology Relating to Thermal Analysis and Rheology
E794 Test Method for Melting And Crystallization Temperatures By Thermal Analysis
E928 Test Method for Purity by Differential Scanning Calorimetry
E967 Test Method for Temperature Calibration of Differential Scanning Calorimeters and Differential Thermal Analyzers
E1970E3142 Practice for Statistical Treatment of Thermoanalytical DataTest Method for Thermal Lag of Thermal Analysis
Apparatus
3. Terminology
3.1 Specific technical terms used in this test method are defined in Terminology E473.
4. Summary of Test Method
4.1 The temperature sensor of the DSC, used to determine the temperature of a transition, is located close to but external to the
test specimen. This arrangement causes the indicated temperature to lead or lag the actual specimen temperature on heating/cooling
causing the reported temperature to be higher on heating and lower on cooling than the actual specimen transition temperature.
A DSC apparatus temperature, temperature sensor, that has been calibrated for heating experiments, needs to be re-calibrated for
cooling experiments. Such a calibration on cooling is performed using a liquid crystal crystal, polymorphic, or other material, the
transition(s) for which are not subject to super-heating or super-cooling.
This test method is under the jurisdiction of ASTM Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.01 on Calorimetry
and Mass Loss.
Current edition approved April 1, 2018Sept. 1, 2019. Published May 2018September 2019. Originally approved in 2000. Last previous edition approved in 20122018 as
E2069 – 06 (2012).(2018). DOI: 10.1520/E2069-06R18.10.1520/E2069-19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2069 − 19
4.2 The transition temperature of a rapid, non-superheating and non-supercooling transition is determined upon heating and
upon cooling. The difference between these two indicated temperatures provides an offset temperature value between heating and
cooling experiments at the indicated rate. This offset temperature value, when used with a precise temperature calibration upon
heating, may serve as an instrument calibration function upon cooling.
4.3 The determination and use of thermal lag using Test Method E3142 is an alternative to this test method.
5. Significance and Use
5.1 This test method is useful in calibrating the temperature signal of a differential scanning calorimeter DSC for cooling
experiments such as the determination of crystallization temperatures in Test Method D3418 and Test Method E794.
5.2 This test method may be used for research, development, analytical, specification acceptance, quality assurance, and control
purposes.
6. Precautions
6.1 Toxic or corrosive effluents, or both, may be released when heating the material of this test method and may be harmful to
personnel and to the apparatus.
7. Apparatus
7.1 Differential Scanning Calorimeter (DSC)—The essential instrumentation required providing the minimum differential
scanning calorimeter DSC capability for this test method includes:
7.1.1 A DSC Test Chamber, composed of:
7.1.1.1 A Furnace(s), to provide uniform controlled heating and cooling of a specimen and reference material to a constant
temperature or at a constant rate within the applicable temperature range of this test method.
7.1.1.2 A Temperature Sensor, that indicates specimen or furnace temperature to 60.01°C.60.01 °C.
7.1.1.3 A Differential Sensor, to detect a heat flow difference (DSC) between the specimen and reference with a range of at least
100 mW readable to 61 μW (DSC).μW.
7.1.1.4 A means of sustaining a purge gas rate of 10 mL/min to 100 6 5 mL/min in the test chamber.
NOTE 1—Typically inert purge gases that inhibit specimen oxidation are 99+ % pure nitrogen, argon or helium. Subambient operation requires dry
purge gases. Dry gases are recommended for all experiments unless the effect of moisture is part of the study.
7.1.2 A Temperature Controller, capable of executing a specific temperature program by operating the furnace or furnaces
between selected temperature limits at a rate of temperature change of 10°C/min up to 10 °C/min constant to within 60.1°C/min
60.1 °C/min or at an isothermal temperature constant to 60.1°C.60.1 °C.
7.1.3 A Recording Data Collection Device, capable of recording and displaying fractions of the heat flow signal (DSC curve),
including the signal noise, on the Y-axis versus fractions of temperature signal, including the signal noise, on the X-axis.to provide
a means of acquiring, storing, and displaying measured or calculated signals, or both. The minimum output signals required for
differential scanning calorimetry are heat flow, temperature, and time.
7.1.4 Containers,Containers (pans, crucibles, vials, lids, closures, seals, etc.)etc.), that are inert to the specimen and reference
materials and that are of suitable structural shape and integrity to contain the specimen and reference in accordance with the
requirements of this test method.
NOTE 2—DSC Differential scanning calorimeter containers are commonly composed of aluminum or other inert material of high thermal conductivity.
Aluminum has containers supplied by thermal analysis venders have been tested and found compatible with the materials used in this test method.
7.1.5 Cooling Capability, at constant cooling rates of up to 10°C/min 10 °C/min in the temperature range of 185 to 50°C, to
user interest, to hasten cool down from elevated temperatures, or to sustain an isothermal subambient temperature, or both.
7.2 A Balance, to weigh specimen and/or containers to 610 μg with a capacity of 100 mg or greater.
8. Calibration Materials
8.1 For the temperature range covered by many applications, the liquid crystal transitions of 99.8 % to 99.9 % pure materials
in Table 1 may be used for calibration. The calibrating liquid crystal materials are known as M-24, BP-53 and BCH-52.BP-53,
and BCH-52, and other materials shown in Table 1 are useful for this purpose.
NOTE 3—The purity of these liquid crystal materials may be determined by Test Method E928 using the first liquid crystal indicated transition prior
to use (see use.Table 2).
The sole source of supply of these materials known to the committee at this time is EMD Chemicals Inc., 480 S. Democrat Road, Gibbstown, NJ 08027–1296. The part
numbers for these chemicals are as follows: M-24 is pn 1.00008.9005, BP-53 is pn 1.00007.9005 and BCH-52 is pn 1.00006.9005. If you are aware of alternative suppliers,
please provide this information to ASTM headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may
attend.
E2069 − 19
TABLE 1 Transition Temperatures for Selected Liquid Crystal
Calibration Materials
Transition
Liquid Crystal Transition C
Temperature,
A B
Material Type
K °C
M-24 Cr →S 327.5 54.5
A
S → N 340.2 67.1
A
BP-53 S → N 393.6 120.5
A
BCH-52 N → I 437.9 164.8
TABLE 1 Transition Temperatures for Selected Calibration
Materials
Transition Maximum
Enthalpy
Transition C
A
Temperature Temperature
Material
B
Type
K °C J/g °C
Adamantane Cr → Cr 207.61 –65.54 30
1 2
M-24 Cr → S 327.5 54.5
A
S → N 340.2 67.1 0.08 97
A
BP-53 S → N 393.6 120.5 0.6 130
A
BCH-52 N → I 437.9 164.8 1.3 184
D
Zinc Cr → I 692.677 419.527 439
A
M-24 = 4-Cyano-4’-octyloxybiphenyl
BP-53 = 4-(4-Pentyl-cyclohexyl)-benzoic acid-4-propyl-phenyl ester
BCH-52 = 4’-Ethyl-4-(4-propyl-cyclohexyl)-biphenyl
B
Ch = Cholesteric
Cr = Crystalline
I = Isotropic liquid
N = Nematic
S = Smectic A
A
S = Smectic C
C
S = Chira
...