ASTM E474-80

Method for Evaluaton of Temperature Scale for Differential Thermal Analysis (Withdrawn 1986)

General Information

• Status: Withdrawn
• ICS: 01.040.17 - Metrology and measurement. Physical phenomena (Vocabularies)
• ICS: 17.200.10 - Heat. Calorimetry
• Technical Committee: E37 - Thermal Measurements

Standards Content (Sample)

~~l~ Designation: E 474- 80
Standard Method for
EVALUATION OF TEMPERATURE SCALE FOR
DIFFERENTIAL THERMAL ANALYSIS'
This stan~a.rd is issue.d und~r the fixed desig.n~tion E 474: the number immediately following the designation indicates the
year of ongmal adoptiOn or, m the case ofrevtswn, the year of last rcvi~ion. A number in parentheses indicates the year of last
reapproval.
the useful range of the instrument and at two
I. Scope
or more heating rates will be an aid in deter­
1.1 This method for evaluation of the tem­
mining the characteristics of the operator's in­
perature scale is for general use in differential
strument.
thermal analysis. It provides a way of relating
temperatures of events observed in different
3. Definitions of Terms and Abbreviations
laboratories and with different instruments.
3.1 This list includes definitions that agree
1.2 The method is applicable to all commer­
with those adopted by the International Con­
cial and custom-built apparatus. It can also be
federation for Thermal Analysis (1977).
used for instruments classed as differential
3.1.1 differential thermal analysis (DTA)-a
scanning calorimeters.
technique in which the temperature difference
1.3 The purpose of this rriethod is to deter­
between a substance and a reference material
mine the agreement in temperature under the
is measured as a function of temperature while
specific conditions of the principal experiment,
the substance and the reference material are
and not to determine the transition temperature
subjected to a controlled temperature program.
of the ICTA Certified Reference MateriaL It is
The record is the differential thermal or DT A
necessary to use the same sample holder assem­
curve; the. temperature difference (a'.f) should
bly and heating rate in obtaining the peak(s)
be plotted on the ordinate with endothermic
whose temperature(s) is to be related to other
reactions downwards and tor Ton the abscissa
determinations.
increasing from left to right.
2. Summary of Method 3.1.2 quantitative differentia/thermal analysis
(quantitative DTA)-this term covers those uses
2.1 The method consists of obtaining the
of DTA where the equipment is designed to
differential thermal analysis peak of one or
produce quantitative results in terms of energy
more of the ICTS Certified Reference Mate­
and/or other physical parameters. The record
rials under the normal operating conditions of
should be plotted in the same manner as a
the instrument, determining the extrapolated
normal DT A curve.
onset and peak temperatures, and comparing
3.1.3 differential scanning calorimetry
these temperatures with those established for
(DSC)-a technique in which the difference in
the material. The difference provides an ad­
energy inputs into a substance and a reference
justment which may be applied in relating data
material is measured as a function of tempera-
on test substances to data obtained on other
instruments.
1
• Th.is method is under the jurisdiction of ASTM Com­
2.2 In correlating measurements, it will be
mtttee E-37 on Thermal Measurements and is the direct
necessary only to use ICTA Certified Reference
responsibility of Subcommittee E37.0l on Test Methods and
Recommended Practices.
Materials whose peak temperatures are in the
Current edition approved Aug. I. 1980. Published Sep­
range of those of the test substance. However,
tember 1980. Origmally published as E474-73. Last pre­
use ofiCTA Certified Reference Materials over vious editiOn E 474- 73.
647

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E 474
ture while the substance and the reference ma­ the International Confederation for Thermal
terial are subjected to a controlled temperature Analysis and the National Bureau of Stand­
program. Two modes, power compensation dif­ ards. The certified values are the means of
ferential scanning calorimetry (power-compen­
values obtained by 34 laboratories. They are
sation DSC) and heat-flux differential scanning available in sets from the National Bureau of
calorimetry (heat-flux DSC), can be distin­ Standards, GM 757, 758, 759, and 760.
guished depending on the method of measure­ 6.2.1 GM 757-1,2-dichloroethane, cyclo­
ment used. The record is the DSC curve; the hexane, phenyl ether, o-terphenyl; temperature
energy input is substituted for AT and it is range: 180 to 330 K.
plotted in the same manner as a normal DTA
6:2.2 GM 758-KNO,, In (metal), Sn
curve. (metal), KClO,, Ag SO,; temperature range:
2
3.1.4 test substance-the material whose 401 to 703 K.
DT A curve is to be compared to the DT A
6.2.3 GM 759-KClO,, Ag,SO,, SiO,,
curve obtained on another instrument. K2S04, K2Cr0 ; temperature range: 572 to 928
4
3.1.5 peak-that portion of the DTA curve K.
which departs from and subsequently returns
6.2.4 GM 76Q-Si02, K2S04, K2Cr04,
to a base line. BaCO,, SrCO,; temperature range: 846 to 1198
3.1.6 extrapolated onset-the point of inter­
K.
se
...