ASTM E2040-99

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 2040 – 99
Standard Test Method for
Mass Scale Calibration of Thermogravimetric Analyzers
This standard is issued under the fixed designation E 2040; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope of thermogravimetric apparatus at ambient conditions. Most
thermogravimetry analysis experiments are carried out under
1.1 This test method covers the calibration or performance
temperature ramp conditions or at isothermal temperatures
confirmation of the mass (or weight) scale of thermogravimet-
distant from ambient conditions. This test method does not
ric analyzers and is applicable to commercial and custom-built
address the temperature effects on mass calibration.
apparatus.
5.2 In most thermogravimetry experiments, the mass
1.2 Electronic instrumentation or automated data analysis
change is reported as weight percent in which the observed
and reduction systems or treatments equivalent to this test
mass at any time during the course of the experiment is divided
method may be used.
by the original mass of the test specimen. This method of
1.3 The values stated in SI units are to be regarded as the
reporting results assumes that the mass scale of the apparatus
standard.
is linear with increasing mass. In such cases, it may be
1.4 There is no ISO standard equivalent to this test method.
necessary only to confirm the performance of the instrument by
1.5 This standard does not purport to address all of the
comparison to a suitable reference.
safety concerns, if any, associated with its use. It is the
5.3 When the actual mass of the test specimen is recorded,
responsibility of the user of this standard to establish appro-
the use of a calibration factor to correct the calibration of the
priate safety and health practices and determine the applica-
apparatus may be required, on rare occasions.
bility of regulatory limitations prior to use.
6. Apparatus
2. Referenced Documents
6.1 The essential equipment required to provide the mini-
2.1 ASTM Standards:
mum thermogravimetric analytical capability for this test
E 473 Terminology Relating to Thermal Analysis
method includes the following:
E 691 Practice for Conducting an Interlaboratory Study to
2 6.1.1 Thermobalance, composed of a furnace;a tempera-
Determine the Precision of a Test Method
ture sensor;a balance to measure the specimen mass with a
E 1142 Terminology Relating to Thermophysical Proper-
2 minimum capacity within the range to be calibrated and a
ties
sensitivity of 6 1 μg; and a means of maintaining the
3. Terminology specimen/container under atmospheric control of the gas to be
used at a purge rate between 10 to 1006 5 mL/min.
3.1 Definitions—Specific technical terms used in this test
method are defined in accordance with Terminologies E 473
NOTE 1—Excessive purge rates should be avoided as this may intro-
and E 1142.
duce noise due to bouyancy effects and temperature gradients.
6.1.2 Temperature Controller, capable of maintaining am-
4. Summary of Test Method
bient temperature to 6 1K.
4.1 The mass signal generated by a thermogravimetric
6.1.3 Recording Device, either analog or digital, capable of
analyzer is compared to the mass of a reference material
recording and displaying any fraction of the specimen mass
traceable to a national reference laboratory. A linear correlation
signal including the signal noise.
using two calibration points is used to relate the mass (or
6.1.4 Containers (pans, crucibles, etc.), which are inert to
weight) signal generated by the thermogravimetric analyzer
the specimen and which will remain gravimetrically stable.
and that of the reference material.
7. Reagents and Materials
5. Significance and Use
7.1 A reference material of known mass, which is traceable
5.1 This test method calibrates or demonstrates conformity
to a national standards laboratory, such as the National Institute
of Standards and Technology (NIST). Such mass reference
materials are available from most general laboratory equipment
This test method is under the jurisdiction of ASTM Committee E-37 on
Thermal Measurements and is the direct responsibility of Subcommittee E37.01 on
suppliers.
Test Methods and Recommended Practices.
7.2 The mass of the reference material should correspond to
Current edition approved Sept. 10, 1999. Published October 1999.
the working range of the analysis. For most work, the mass
Annual Book of ASTM Standards, Vol 14.02.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
E 2040
should be 25 to 50 % greater than the material being examined. 10.3.1.3 Between 0.9900 and 0.9990 or between 1.0010 and
1.0100, then conformity is better than 1 %.
8. Calibration and Standardization
10.3.1.4 Between 0.9000 and 0.9900 or between 1.0100 and
8.1 Perform any mass signal calibration procedures recom-
1.1000, then conformity is better than 10 %.
mended by the manufacturer of the thermogravimetric analyzer 10.4 Report the value of S an
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