ASTM E2069-06(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E2069 − 06 (Reapproved 2012)
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 E1970 PracticeforStatisticalTreatmentofThermoanalytical
Data
1.1 This test method covers the temperature calibration of
differential scanning calorimeters on cooling using the differ-
3. Terminology
ence between transition temperatures upon heating and cooling
3.1 Specific technical terms used in this test method are
in the temperature range of 50 to 185°C. An offset in the
defined in Terminology E473.
indicated temperature between heating and cooling
experiments, within this temperature range, may be used to
4. Summary of Test Method
providetemperaturecalibrationoncoolingatothertemperature
4.1 The temperature sensor of the DSC, used to determine
ranges.
the temperature of a transition, is located close to but external
1.2 The values stated in SI units are to be regarded as
to the test specimen. This arrangement causes the indicated
standard. No other units of measurement are included in this
temperature to lead or lag the actual specimen temperature on
standard.
heating/cooling causing the reported temperature to be higher
1.3 This standard does not purport to address all of the
on heating and lower on cooling than the actual specimen
safety concerns, if any, associated with its use. It is the
transition temperature. A DSC apparatus temperature, that has
responsibility of the user of this standard to establish appro-
been calibrated for heating experiments, needs to be re-
priate safety and health practices and determine the applica-
calibrated for cooling experiments. Such a calibration on
bility of regulatory limitations prior to use. Specific precau-
cooling is performed using a liquid crystal material, the
tionary statements are given in Section 6.
transition(s) for which are not subject to super-heating or
super-cooling.
2. Referenced Documents
2 4.2 The transition temperature of a rapid, non-superheating
2.1 ASTM Standards:
and non-supercooling transition is determined upon heating
D3418 Test Method for Transition Temperatures and En-
and upon cooling. The difference between these two indicated
thalpies of Fusion and Crystallization of Polymers by
temperatures provides an offset temperature value between
Differential Scanning Calorimetry
heating and cooling experiments at the indicated rate. This
E473 Terminology Relating to Thermal Analysis and Rhe-
offset temperature value, when used with a precise temperature
ology
calibration upon heating, may serve as an instrument calibra-
E794 Test Method for MeltingAnd CrystallizationTempera-
tion function upon cooling.
tures By Thermal Analysis
E928 Test Method for Purity by Differential Scanning Calo-
5. Significance and Use
rimetry
5.1 This test method is useful in calibrating the temperature
E967 Test Method for Temperature Calibration of Differen-
signal of a differential scanning calorimeter for cooling experi-
tial Scanning Calorimeters and Differential Thermal Ana-
ments such as the determination of crystallization temperatures
lyzers
in Test Method D3418 and Test Method E794.
ThistestmethodisunderthejurisdictionofASTMCommitteeE37onThermal 5.2 This test method may be used for research,
Measurements and is the direct responsibility of Subcommittee E37.01 on Calo-
development, analytical, specification acceptance, quality as-
rimetry and Mass Loss.
surance and control purposes.
Current edition approved Sept. 1, 2012. Published September 2012. Originally
approved in 2000. Last previous edition approved in 2006 as E2069 – 06. DOI:
6. Precautions
10.1520/E2069-06R12.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.1 Toxic or corrosive effluents, or both, may be released
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
when heating the material of this test method and may be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. harmful to personnel and to the apparatus.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2069 − 06 (2012)
TABLE 1 Transition Temperatures for Selected Liquid Crystal
7. Apparatus
Calibration Materials
7.1 DifferentialScanningCalorimeter(DSC)—Theessential
C
Transition Temperature,
Liquid Crystal
B
instrumentation required providing the minimum differential Transition Type
A
Material
K°C
scanning calorimeter capability for this test method includes:
M-24 Cr→S 327.5 54.5
A
7.1.1 A DSC Test Chamber, composed of:
S → N 340.2 67.1
A
7.1.1.1 A Furnace(s), to provide uniform controlled heating BP-53 S → N 393.6 120.5
A
BCH-52 N→ I 437.9 164.8
and cooling of a specimen and reference material to a constant
A
M-24 = 4-Cyano-4’-octyloxybiphenyl
temperatureorataconstantratewithintheapplicabletempera-
BP-53 = 4-(4-Pentyl-cyclohexyl)-benzoic acid-4-propyl-phenyl ester
ture range of this method.
BCH-52 = 4’-Ethyl-4-(4-propyl-cyclohexyl)-biphenyl
B
7.1.1.2 A Temperature Sensor, that indicates specimen or Ch = Cholesteric
Cr = Crystalline
furnace temperature to 60.01 °C.
I = Isotropic liquid
7.1.1.3 ADifferentialSensor,todetectaheatflowdifference
N = Nematic
(DSC) between the specimen and reference with a range of at S = Smectic A
A
S = Smectic C
C
least 100 mW readable to 61 µW (DSC).
S = Chiral smectic C
C*
7.1.1.4 A means of sustaining a purge gas rate of 10 to 100
S = Smectic I*
I*
6 5 mL/min in the test chamber. S = Smectic J*
J*
C
The transition temperatures are dependent upon the purity of the liquid crystal
NOTE1—Typicallyinertpurgegasesthatinhibitspecimenoxidationare material.These transition temperatures are those for 99.9+ mol % pure materials.
99+ % pure nitrogen, argon or helium. Subambient operation requires dry See Footnotes 5.
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
7.2 A Balance, to weigh specimen and/or containers to 610
furnaces between selected temperature limits at a rate of
µg with a capacity of 100 mg or greater.
temperature change of 10 °C/min constant to within 60.1°C/
min or at an isothermal temperature constant to 60.1°C.
8. Calibration Materials
7.1.3 ARecordingDevice,capableofrecordinganddisplay-
8.1 For the temperature range covered by many
ing fractions of the heat flow signal (DSC curve), including the
applications, the liquid crystal transitions of 99.8 to 99.9 %
signal noise, on the Y-axis versus fractions of temperature
pure materials in Table 1 may be used for calibration. The
signal, including the signal noise, on the X-axis.
calibrating liquid crystal materials are known as M-24, BP-53
7.1.4 Containers, (pans, crucibles, vials, lids, closures,
and BCH-52.
seals, etc.) that are inert to the specimen and reference
materials and that are of suitable structural shape and integrity NOTE3—Thepurityoftheseliquidcrystalmaterialsmaybedetermined
by Test Method E928 using the first liquid crystal transition prior to use
to contain the specimen and reference in accordance with the
(see Table 2).
requirements of this test method.
NOTE 2—DSC containers are commonly composed of aluminum or
other inert material of high thermal conductivity. Aluminum has been
The sole source of supply of these materials known to the committee at this
tested and found compatible with the materials used in this standard.
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,
7.1.5 Cooling Capability, at constant cooling rates of up to
BP-53 is pn 1.00007.9005 and BCH-52 is pn 1.00006.9005. If you are aware of
10°C/min in the temperature range of 185 to 50°C, to hasten
alternative suppliers, please provide this informatio
...