ASTM C1909-21

Standard Test Method for Moisture Analysis of Plutonium Dioxide (PuO<inf>2</inf>) by Thermogravimetric Mass Spectrometry (TGA-MS)

SIGNIFICANCE AND USE
5.1 This test method is intended for use in quality control laboratories where a quantitative analysis of adsorbed moisture on a PuO2 sample is desired.  
5.2 The parameters described should be considered as guidelines. They may be altered to suit a particular analysis or type of analyzer, provided the changes are validated by the laboratory and noted in the report.  
5.3 The quantity of an adsorbed gas on a given PuO2 sample may indicate specific quality or end use performance characteristics. Specific limits on moisture content, for example, are required in cases where PuO2 will be packaged and stored for extended periods of time.
SCOPE
1.1 This test method provides necessary information to determine the total amount of moisture (physisorbed and chemisorbed water molecules) in a plutonium dioxide (PuO2) sample using a combination of thermogravimetric and mass spectrometric analyses. This test method is useful when performing analysis in cases where a maximum amount of moisture content in PuO2 samples has been agreed upon by interested parties. For example this method can be used to determine the moisture content of some types of PuO2 packaged to meet the requirements of DOE-STD-3013 (1),2 “Stabilization, Packaging, and Storage of Plutonium-Bearing Materials,” when such PuO2 meets the specifications given in this test method (2).  
1.2 This test method is applicable to PuO2 samples having the following characteristics: Plutonium mass fraction ≥ 83 % (the plutonium in the sample should be close to stoichiometric PuO2 which is approximately 88 wt% plutonium depending on the isotopic composition of the plutonium, but can have several weight percent impurities), moisture ≤1 %.  
1.3 The temperature range of test is typically room temperature to greater than 1000 °C. Typically the PuO2 is heated to 1100 °C.  
1.4 This test method utilizes an inert gas environment (argon, nitrogen, or helium).  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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.

General Information

• Status: Published
• Publication Date: 31-May-2021
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM E473-23b - Standard Terminology Relating to Thermal Analysis and Rheology
• Effective Date: 01-Oct-2023
• Refers: ASTM E1142-23b - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 01-Oct-2023
• Refers: ASTM E1142-15 - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 01-May-2015
• Refers: ASTM E473-14 - Standard Terminology Relating to Thermal Analysis and Rheology
• Effective Date: 15-Aug-2014
• Refers: ASTM E1142-14b - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 15-Aug-2014
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM E1142-14a - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 01-Apr-2014
• Refers: ASTM E1142-14 - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 15-Feb-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013
• Refers: ASTM E1142-12 - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 01-Sep-2012
• Refers: ASTM C1210-12 - Standard Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories Within the Nuclear Industry
• Effective Date: 01-Jun-2012
• Refers: ASTM E1142-11b - Standard Terminology Relating to Thermophysical Properties
• Effective Date: 01-Aug-2011

Overview

ASTM C1909-21 - Standard Test Method for Moisture Analysis of Plutonium Dioxide (PuO₂) by Thermogravimetric Mass Spectrometry (TGA-MS) provides a robust protocol for accurately determining total moisture content (both physisorbed and chemisorbed water) in plutonium dioxide samples. Developed by ASTM, this international standard is particularly significant for quality control laboratories responsible for the stabilization, packaging, and long-term storage of plutonium-bearing materials. The method enables quantitative assessment of adsorbed moisture, which is a critical parameter in ensuring the safe handling, storage, and end-use performance of PuO₂.

Key Topics

• Moisture Determination in PuO₂: The standard details procedures to quantitatively analyze the total moisture content (≤1%) in plutonium dioxide samples with a plutonium mass fraction of ≥83%.
• Thermogravimetric Mass Spectrometry (TGA-MS): Combines thermal analysis and mass spectrometry to detect and measure moisture released as the sample is heated, typically up to 1100°C, in an inert gas atmosphere (argon, nitrogen, or helium).
• Quality Control and Compliance: Establishes guidelines for laboratories to validate and record deviations in the analytical method, ensuring customized approaches are properly documented and results remain reliable.
• Calibration and Equipment: Specifies requirements for calibration of balances, temperature control, and gas flow, as well as recommendations for suitable reference materials.
• Reporting and Documentation: Outlines essential data to include in quality and compliance reports, covering sample information, laboratory conditions, method versions, and calibration details.

Applications

Moisture analysis of plutonium dioxide is essential in a variety of nuclear fuel cycle contexts:

• Nuclear Material Packaging and Storage: Ensures compliance with regulatory standards, such as DOE-STD-3013, where strict moisture limits are required to prevent corrosion and maintain safety during extended storage.
• Quality Assurance in Production and Handling: Supports laboratories in certifying that PuO₂ samples meet specified moisture criteria, which can impact the suitability and longevity of the material for further processing or storage.
• Research and Development: Provides a validated approach for R&D environments investigating the chemical and physical stability of plutonium compounds under controlled atmospheres.
• Process Optimization: Helps in refining production and purification steps by enabling precise moisture monitoring, which is crucial for maintaining product consistency.

Related Standards

For comprehensive implementation, laboratories and stakeholders may refer to additional ASTM standards and relevant documentation, including:

• ASTM C859: Terminology Relating to Nuclear Materials
• ASTM C1210: Guide for Measurement System Quality Control for Analytical Chemistry Laboratories in the Nuclear Industry
• ASTM E473: Terminology Relating to Thermal Analysis and Rheology
• ASTM E967: Test Method for Temperature Calibration of Calorimeters
• ASTM E1582: Test Method for Temperature Calibration of Thermogravimetric Analyzers
• DOE-STD-3013: Stabilization, Packaging, and Storage of Plutonium-Bearing Materials

Practical Value

Implementing ASTM C1909-21 enhances accuracy, traceability, and safety for organizations managing plutonium dioxide:

• Reliable Moisture Quantification: Reduces risks related to moisture-induced degradation or reactivity during storage.
• Regulatory Confidence: Facilitates compliance with national and international standards in nuclear material management.
• Customizable Procedure: Offers flexibility for laboratories to adapt the method to specific instruments and analytical needs, provided such modifications are validated and reported.
• Data Quality Assurance: Emphasizes calibration, representative sampling, and appropriate documentation for trustworthy results.

Keywords

Plutonium dioxide, PuO₂, moisture analysis, thermogravimetric mass spectrometry, TGA-MS, ASTM C1909-21, nuclear material quality control, inert gas environment, sample calibration, storage safety.

Standards Content (Sample)

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.
Designation: C1909 − 21
Standard Test Method for
Moisture Analysis of Plutonium Dioxide (PuO )by
Thermogravimetric Mass Spectrometry (TGA-MS)
This standard is issued under the fixed designation C1909; 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 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This test method provides necessary information to
ization established in the Decision on Principles for the
determine the total amount of moisture (physisorbed and
Development of International Standards, Guides and Recom-
chemisorbed water molecules) in a plutonium dioxide (PuO )
mendations issued by the World Trade Organization Technical
sample using a combination of thermogravimetric and mass
Barriers to Trade (TBT) Committee.
spectrometric analyses. This test method is useful when per-
forming analysis in cases where a maximum amount of
2. Referenced Documents
moisture content in PuO samples has been agreed upon by
2.1 ASTM Standards:
interested parties. For example this method can be used to
C859 Terminology Relating to Nuclear Materials
determine the moisture content of some types of PuO pack-
2 C1210 Guide for Establishing a Measurement System Qual-
aged to meet the requirements of DOE-STD-3013 (1),
ity Control Program for Analytical Chemistry Laborato-
“Stabilization, Packaging, and Storage of Plutonium-Bearing
ries Within Nuclear Industry
Materials,” when such PuO meets the specifications given in
E473 Terminology Relating to Thermal Analysis and Rhe-
this test method (2).
ology
1.2 This test method is applicable to PuO samples having
E967 Test Method for Temperature Calibration of Differen-
the following characteristics: Plutonium mass fraction ≥ 83 %
tial Scanning Calorimeters and Differential Thermal Ana-
(the plutonium in the sample should be close to stoichiometric
lyzers
PuO which is approximately 88 wt% plutonium depending on
E1142 Terminology Relating to Thermophysical Properties
theisotopiccompositionoftheplutonium,butcanhaveseveral
E1582 Test Method for Temperature Calibration of Thermo-
weight percent impurities), moisture ≤1%.
gravimetric Analyzers
1.3 Thetemperaturerangeoftestistypicallyroomtempera-
3. Terminology
ture to greater than 1000 °C. Typically the PuO is heated to
1100 °C.
3.1 Definitions:
3.1.1 Except as otherwise defined herein, definitions of
1.4 This test method utilizes an inert gas environment
terms are as given in Terminology C859, E473, and E1142.
(argon, nitrogen, or helium).
3.2 Definitions of Terms Specific to This Standard:
1.5 The values stated in SI units are to be regarded as
3.2.1 rotary riffler, n—a piece of laboratory equipment
standard. No other units of measurement are included in this
capable of subdividing large samples into smaller sub-samples
standard.
by means of vibration of the large sample into a rotating set of
1.6 This standard does not purport to address all of the
sub-sample containers.
safety concerns, if any, associated with its use. It is the
3.2.1.1 Discussion—This technique minimizes operator er-
responsibility of the user of this standard to establish appro-
ror and bias as compared with many other types of sample
priate safety, health, and environmental practices and deter-
dividing.
mine the applicability of regulatory limitations prior to use.
4. Summary of Test Method
4.1 This test method is an empirical technique using ther-
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear mogravimetry and mass spectrometry in which the mass of a
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test.
Current edition approved June 1, 2021. Published July 2021. DOI: 10.1520/ For referenced ASTM standards, visit the ASTM website, www.astm.org, or
C1909-21. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
The boldface numbers in parentheses refer to a list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this standard. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1909 − 21
analyzer specific. Examples include heat rate, type of carrier gas, mass of
sample of PuO , heated at a controlled rate in a gaseous
sample, etc.
environmentofknowncompositionisrecordedasafunctionof
time and temperature while the evolved moisture is measured 7.1.2 Temperature Controller, capable of executing a spe-
simultaneouslyonamassspectrometer.Masslossoverspecific cific temperature program by operating the furnace between
temperature ranges and recorded signals corresponding to selectedtemperaturelimitsandcapableofaheatingrateofless
water are measured to provide a compositional analysis of the than 10 °C/min constant to within 61 % for a minimum of
moisture in the PuO sample. 120 min.
7.1.3 Data Collection Device, to provide a means of
5. Significance and Use
acquiring, storing, and displaying measured or calculated
signals, or both. The minimum output signals required for
5.1 This test method is intended for use in quality control
TGA-MS analyzers are mass, temperature, time and ion
laboratories where a quantitative analysis of adsorbed moisture
current.
on a PuO sample is desired.
NOTE 2—The capability to display the first derivative of the signal may
5.2 The parameters described should be considered as
be useful in the measurement of obscure thermostability ranges.
guidelines. They may be altered to suit a particular analysis or
type of analyzer, provided the changes are validated by the 7.1.4 Containers (Pans, Crucibles, Etc.), which are inert to
the specimen and which will remain dimensionally stable
laboratory and noted in the report.
within the temperature limits of this test method. Examples
5.3 ThequantityofanadsorbedgasonagivenPuO sample
include alumina and platinum-rhodium alloy pans or crucibles.
may indicate specific quality or end use performance charac-
7.1.5 Gas Flow Control Device, with the capability of
teristics. Specific limits on moisture content, for example, are
controlling flow of carrier gas. Gas flow control device, with
required in cases where PuO will be packaged and stored for
the capability of controlling flow of carrier gas.
extended periods of time.
7.1.6 Mass Spectrometer, capable of a resolution of
≤1 AMU in the mass range 17 AMU to 18 AMU.
6. Interferences
7.1.7 Heated Transfer Line, capable of transferring evolved
6.1 PuO samples which contain impurities that could
moisture from the TGA chamber to the mass spectrometer.
undergo chemical reactions (for example, redox reactions) or
7.1.8 Chiller, used to provide chilled water for cooling the
phase changes which would result in mass differences not
furnace between samples.
related to devolatilization of sorbed or structural gases must
7.1.9 Relative Humidity Detector, for measuring the RH of
haveaspecifictemperatureand/ortimeregionidentifiedforthe
the glovebox atmosphere (0 % to 100 % RH).
measurement.Anexampleofthisismetallicgalliumwhichcan
7.1.10 Regulator, for the compressed inert carrier gas.
exist in some PuO samples and may oxidize at high tempera-
7.1.11 Laboratory Balance, capable of measuring 3 g 6
tures causing a mass gain. Although not part of this test
0.1 mg readability, 60.1 mg repeatability, for measuring items
method, heat flow / heat capacity can be measured in parallel
outside of the TGA-MS.
with the thermogravimetric analyzer (TGA) measurement via
7.1.12 Gas Bench, for distribution of the inert carrier gas.
differential scanning calorimetry (DSC) or differential thermal
7.1.13 Rotary Riffler, for subdividing larger powder samples
analysis (DTA) to verify that increases and decreases in mass
into smaller sub-samples.
correspond to attributable exothermic or endothermic chemical
reactions and phase changes.
8. Reagents and Materials
8.1 Ultra High Purity (UHP) compressed inert gas,
7. Apparatus and Other Equipment
99.999 % purity, meeting the following additional specifica-
7.1 The minimum essential equipment required for thermo-
tions:
gravimetric and mass spectrometric analysis capability for this
8.1.1 Maximum water content of 1.0 µg⁄g,
test method includes:
8.1.2 Maximum hydrocarbon content of 0.5 µg/g,
7.1.1 Thermobalance, composed of (1) a furnace to provide
8.1.3 Maximum oxygen content of 1 µg/g, and
uniform controlled heating of a specimen to a constant tem-
8.1.4 Maximum total impurities of 100 µg/g.
perature or at a constant rate within 25 °C to 1500 °C, (2) a
8.2 Certified pure metals used for temperature calibration
temperature sensor (thermocouple) to provide an indication of
(see Table 1).
the specimen/furnace temperature to 610.0 °C, (3) an elec-
tronicbalancetocontinuouslymeasurethespecimenmasswith
8.3 Certified reference materials for mass spectrometer
a sensitivity of 62 µg, and (4) a means of sustaining the
moisture calibration (see Table 2).
specimen/container under atmosphere control with a purge rate
3 3
9. Test Samples
of 1 cm /s to 2 cm /s. This purge gas flow is directed to the
mass (60 mL⁄min to 120 mL/min).
9.1 Test samples consist of PuO powder. The amount of
sample needed to evolve measurable amounts of adsorbed
NOTE 1—This test method has been developed using a Netzsch
Simultaneous ThermalAnalyzer (STA)-409PC Luxx coupled to a Pfeiffer moisture will vary depending on the moisture content of the
ThermoStar GSD301T3 mass spectrometer. As noted in 5.2, operating
sample. Test samples are measured as received.
parameters may need to be adjusted for analyzers from different manu-
9.2 Ensure that the analyzed sample is representative of the
facturers. Follow manufacturer instructions for specific operating param-
eters. This does not apply for parameters that are method specific and not parent material from which it is taken. It is suggested that after
C1909 − 21
TABLE 1 Selected Pure Metals and Their Associated Certified Melting Temperatures May Be Used for TGA Temperature Calibration
Element Symbol Melting Temperature (°C) Purity
Indium In 156.6 99.99+ %
Tin Sn 231.9 99.99 %
Bismuth Bi 271.4 99.9995 %
Zinc Zn 419.5 99.999 %
Aluminum Al 660.3 99.999 %
A
961.8
Silver Ag 99.99+ %
B
951.5
Gold Au 1064.2 99.999 %
A
Nickel Ni 1455 99.99+ %
A
Air excluded.
B
In static air atmosphere
TABLE 2 Selected Moisture Standards
Chemical Recommended Purity Volatiles
Ca(SO )2H O >99.8 % H O=20.9%
4 2 2
Mg Si O (OH) N/A H O=4.75%
3 4 10 2 2
the parent material is homogenized in a rotary blender, several water molecules is the most appropriate way of calibrating the
grab samples are taken from different areas of the parent TGA-MS system for water content measurements.
material and combined for a single determination. Use of a
10.1.2 More details related to measurement system quality
rotary riffler to subdivide powder or particulate samples is
controlarefoundinGuideC1210.Thefrequencyofcalibration
mandatory.
and calibration checks are highly dependent on the user’s data
NOTE3—Careshouldbetakennottochangethemoisturecontentofthe
quality objectives, frequency of analyzer use, and other factors
sample compared to the parent PuO material. Moisture is added in
specific to each user. Therefore, this standard does not pre-
discretemonolayerstothesurfaceofPuO atarelativelyfastrateatroom
scribe a specific periodicity, but instead prescribes that the user
temperature. The rate and total absorbable moisture content depends on
assess and formalize a calibration and calibration check fre-
the physical properties of the PuO (specific surface area, particle size)
and the relative humidity (RH) and pressure of the atmosphere to which quency based on the specific goals of the user.
the sample is exposed. Researchers have proposed a complex multi-step
10.2 Calibration Procedure:
model for the adsorption and desorption of HOontoPuO involving a
2 2
mix of chemical and physical phenomena (3-6). Desorption of moisture 10.2.1 Calibrate the TGA balance per the manufacturer’s
from the surface of PuO may not progress as easily or rapidly but does
2 instructions. In most modern instruments this can be done by
occur with increases in temperature, decreases in pressure, RH, or
actuating an automatic sequence that uses a specially-designed
combinations thereof (7).
internal weight.
10. Calibration
NOTE 4—Calibrated check weight sets can be purchased separately and
used to confirm calibrations made by the internal weight if required.
10.1 General Guidance:
10.1.1 Balance calibration, temperature signal calibration,
10.2.2 Calibrate the temperature signal from the apparatus
mass spectrometer (evolved moisture) calibration should be
according to the following steps (alternatively, Test Method
performed on an annual basis (at minimum) and immediately
E1582 may also be used as it is an acceptable method forTGA
following instrument transport or repair. Mass spectrometer
temperature calibration). The temperature axis (abscissa) of all
calibration checks should be performed regularly (weekly/
apparent mass change curves must be calibrated accurately by
monthly) and following any change to the transfer line (for
adjusting the temperature measured at the sample to approxi-
example, partial blockages, changes in temperature, cutting or
mate the furnace temperature over the temperature range of
replacement of the capillary column, etc.) or to the mass
interest. This is accomplished by the use of melting point
spectrometer operating parameters (for example, dwell times,
standards. The data generated by steps 10.2.3 – 10.2.20 below
ion source voltages, ion source focusing, ion detection
are used to correct the temperature scale of the instrument by
parameters, etc.). Mass spectrometer calibration checks require
either a positive or negative amount using a multi-point
measuring the release of H O vapor during the decomposition
temperature calibration with best fit line for the generated data.
of compounds with structurally incorporated water molecules
NOTE 5—The following calibration procedure assumes that the indi-
and comparing the analyzer response to the existing calibration
cated temperature of the instrument is linear over the range defined by the
data. It is important to note that no known certified reference
multi-point calibration and that this linearity has been verified.
materials exist for moisture calibration and verification. There-
NOTE 6—Selected pure metals and their associated certified melting
fore the use of pure compounds with structurally-incorporated temperatures are provided in Table 1. Metals should be obtained from, or
C1909 − 21
traceable to, a national standards body.Additional melting point standards
10.2.6 Obtain a clean, empty TGA crucible or pan and
are available and are listed in Test Methods E967 and E1582.
weigh and record tare weight.
NOTE 7—Some of the pure metal standards such as zinc, aluminum and
10.2.7 Using a spatula or tweezers as necessary, transfer
silver, are sensitive to air and humidity. In the case of zinc, oxidation
begins above 225 °C, and therefore each piece of metal can only be used 10 mg to 50 mg of the CRM into the pan or crucible.
once for temperature calibration.
10.2.8 Weigh the full crucible or pan (gross weight) and
NOTE 8—Conditions during temperature calibration runs should closely
record the gross weight.
match those of the subsequent sample measurements.
NOTE 9—High heating rates should be avoided close to the transition
10.2.9 Move the crucible or pan over to theTGAand mount
temperature of the pure metal standards. Heating rates below 20 °C⁄min
on to the carrier.
areacceptable.Heatingrateswellbelow20°C/minmaydecreasetheerror
10.2.10 Close the balance and furnace assembly.
in the temperature calibration further. A heating rate adapted to the
required precision and bias of the method should be selected. Often times
10.2.11 Purgethebalanceandfurnacetubewithinertcarrier
a rate of 10 °C/min is selected for PuO samples. Heating rates during
gas at the appropriate flow rate.
calibration should be the same as heating rates during sample measure-
10.2.12 Check the inert carrier gas flow and adjust, if
ment.
needed.
10.2.3 For temperature calibrations using pure metals, each
10.2.13 Select the appropriate heating profile sequence and
calibration substance has to be cycled three times though each
heating rate configured in step for the CRM loaded in the
melting/crystallizationpoint.Ingeneral,theendtemperatureof
furnace.
theheatingphasesshouldexceedthemeltingpeaksby50 °Cto
10.2.14 Tare the TGA balance so that the mass reads zero.
75 °C. The cooling phases should reach a temperature that is
approximately 75 °C to 100 °C below the melting point in
10.2.15 Start the heating profile sequence.
order to guarantee complete pure metal crystallization.
10.2.16 When the standard melts, the heat flow signal will
10.2.4 Select a minimum of six (ideally eight) pure metal
show an endothermic peak.Atypical curve is shown in Fig. 1.
certified reference materials (CRM) with melting points that
NOTE 11—Most modern TGAanalyzers have subroutines that continu-
cover at a minimum the temperature range of interest for a
ously measure the difference between the observed sample temperature
particular analysis setup (0 °C to 1000 °C).
and the linear change in the furnace temperature to calculate the melting
10.2.5 Using guidance in notes Notes 9-11, configure the
point of the CRM.
heating profile and heating rate for each of the CRMs selected
10.2.17 Allow the analyzer to cool and return to a configu-
in the previous step. Ensure that the maximum and minimum
ration that allows for opening the furnace and removal of the
temperatures selected for the CRM are sufficient to cause
crucible or pan.
complete melting and complete crystallization.
10.2.18 Remove the crucible or pan.
NOTE 10—Most modern TGA analyzers have software that allows the
10.2.19 Repeat ste
...