ASTM E1582-04
(Practice)Standard Practice for Calibration of Temperature Scale for Thermogravimetry
Standard Practice for Calibration of Temperature Scale for Thermogravimetry
SIGNIFICANCE AND USE
Thermogravimetric analyzers are used to characterize a broad range of materials. In most cases, one of the desired values to be assigned in thermogravimetric measurements is the temperature at which significant changes in specimen mass occur. Therefore, the temperature axis (abscissa) of all apparent-mass-change curves must be calibrated accurately, either by direct reading of a temperature sensor, or by adjusting the programmer temperature to match the actual temperature over the temperature range of interest. In the latter case, this is accomplished by the use of either melting point or magnetic transition standards.
This practice permits interlaboratory comparison and intralaboratory correlation of instrumental temperature scale data.
SCOPE
1.1 This practice describe the temperature calibration of thermogravimetric analyzers over the temperature range from 25 to 1500°C and is applicable to commercial and custom-built apparatus. This calibration may be accomplished by the use of either melting point standards or magnetic transition standards.
1.2 The mass change curve in thermogravimetry results from a number of influences, some of which are characteristic of the specimen holder assembly and atmosphere rather than the specimen. The variations from instrument to instrument occur in the point of measurement of the temperature, the nature of the material, its size and packing, the geometry and composition of the specimen container, the geometry and design of the furnace, and the accuracy and sensitivity of the temperature sensor and displaying scales. These all contribute to differences in measured temperatures, which may exceed 20°C. In addition, some sample holder assemblies will show variations of measured temperature with sample size or heating/cooling rate, or both. Since it is neither practical nor advisable to standardize sample holders or thermobalance geometries, instruments may be calibrated by measurement of the deviation of a melting or magnetic (Curie Point) transition temperature from the standard reference temperature. This deviation can be applied as a correction term to subsequent measurements.
1.3 This practice assumes that the indicated temperature of the instrument is linear over the range defined by a two-point calibration and that this linearity has been verified. These two calibration temperatures should be as close to the experimental measurements to be made as possible.
1.4 This practice describes three procedures for temperature calibration of thermogravimetric analyzers using any type balance. Procedures A and B use melting point standards with vertical and horizontal balances. Procedure C uses magnetic transition standards for calibration. Procedure A is designed specifically for use with horizontal-type balances using external furnaces. Procedure B is designed specifically for use with vertical hang-down balances using either internal or external furnaces. No procedure is restricted to the use of the furnace type described in that procedure.
1.5 Computer or electronic-based instruments, techniques, or data treatment equivalent to this procedure may be used.
Note 1—Since all electronic data treatments are not equivalent, the user shall verify equivalency prior to use.
1.6 The data generated by these procedures can be used to correct the temperature scale of the instrument by either a positive or negative amount using either a two-point temperature calibration procedure or a multi-point temperature calibration with best line fit for the generated data.
Note 2—A single-point calibration may be used where this is the only procedure possible or practical. The use of a single-point procedure is not recommended.
1.7 SI units are standard.
1.8 This practice is related to ISO 11358 but provides information and methods not found in ISO 11358 .
1.9 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the res...
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Designation:E1582–04
Standard Practice for
1
Calibration of Temperature Scale for Thermogravimetry
This standard is issued under the fixed designation E1582; 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 nal furnaces. Procedure B is designed specifically for use with
vertical hang-down balances using either internal or external
1.1 This practice describe the temperature calibration of
furnaces. No procedure is restricted to the use of the furnace
thermogravimetric analyzers over the temperature range from
type described in that procedure.
25 to 1500 °C and is applicable to commercial and custom-
1.5 Computer or electronic-based instruments, techniques,
built apparatus. This calibration may be accomplished by the
or data treatment equivalent to this procedure may be used.
use of either melting point standards or magnetic transition
standards.
NOTE 1—Since all electronic data treatments are not equivalent, the
1.2 The mass change curve in thermogravimetry results
user shall verify equivalency prior to use.
from a number of influences, some of which are characteristic
1.6 The data generated by these procedures can be used to
of the specimen holder assembly and atmosphere rather than
correct the temperature scale of the instrument by either a
the specimen. The variations from instrument to instrument
positive or negative amount using either a two-point tempera-
occur in the point of measurement of the temperature, the
ture calibration procedure or a multi-point temperature calibra-
nature of the material, its size and packing, the geometry and
tion with best line fit for the generated data.
composition of the specimen container, the geometry and
NOTE 2—Asingle-point calibration may be used where this is the only
design of the furnace, and the accuracy and sensitivity of the
procedure possible or practical. The use of a single-point procedure is not
temperature sensor and displaying scales. These all contribute
recommended.
to differences in measured temperatures, which may exceed
1.7 The values stated in SI units are to be regarded as
20 °C. In addition, some sample holder assemblies will show
standard. No other units of measurement are included in this
variations of measured temperature with sample size or
standard.
heating/cooling rate, or both. Since it is neither practical nor
1.8 This practice is related to ISO 11358 but provides
advisable to standardize sample holders or thermobalance
information and methods not found in ISO 11358.
geometries, instruments may be calibrated by measurement of
1.9 This standard does not purport to address all of the
the deviation of a melting or magnetic (Curie Point) transition
safety problems, if any, associated with its use. It is the
temperature from the standard reference temperature. This
responsibility of the user of this standard to establish appro-
deviation can be applied as a correction term to subsequent
priate safety and health practices and determine the applica-
measurements.
bility of regulatory limitations prior to use.
1.3 This practice assumes that the indicated temperature of
the instrument is linear over the range defined by a two-point
2. Referenced Documents
calibration and that this linearity has been verified. These two
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2.1 ASTM Standards:
calibration temperatures should be as close to the experimental
E473 Terminology Relating to Thermal Analysis and Rhe-
measurements to be made as possible.
ology
1.4 This practice describes three procedures for temperature
E691 Practice for Conducting an Interlaboratory Study to
calibration of thermogravimetric analyzers using any type
Determine the Precision of a Test Method
balance. Procedures A and B use melting point standards with
E967 Test Method for Temperature Calibration of Differen-
vertical and horizontal balances. Procedure C uses magnetic
tial Scanning Calorimeters and Differential Thermal Ana-
transition standards for calibration. Procedure A is designed
lyzers
specifically for use with horizontal-type balances using exter-
E1142 Terminology Relating to Thermophysical Properties
1
This practice is under the jurisdiction of ASTM Committee E37 on Thermal
Measurements and is the direct responsibility of Subcommittee E37.01 on Calo-
2
rimetry and Mass Loss. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2004. Published June 2004. Originally contact ASTM Customer service at service@astm.org. For Annual Book of ASTM
approved in 1993. Last previous edition approved in 2000 as E1582 – 00. DOI: Standards volume information, refer to the s
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