ASTM E1594-06
(Guide)Standard Guide for Expression of Temperature
Standard Guide for Expression of Temperature
ABSTRACT
This guide presents the uniform methods for expressing temperature, temperature values, and temperature differences. Also covered here are the practical scales, numerical formats, and unit symbol formats used in representing temperature.
SCOPE
1.1 This guide covers uniform methods for expressing temperature, temperature values, and temperature differences.
1.2 This guide is intended as a supplement to IEEE/ASTM SI-10.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E1594–06
Standard Guide for
1
Expression of Temperature
This standard is issued under the fixed designation E1594; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4.4 A temperature difference, interval, or increment is also
described by a numerical value designating the magnitude, a
1.1 This guide covers uniform methods for expressing
unit, and, where appropriate, a tolerance or uncertainty.
temperature, temperature values, and temperature differences.
1.2 This guide is intended as a supplement to IEEE/ASTM
5. Temperature Scales
SI-10.
5.1 Thermodynamic Temperature Scales:
2. Referenced Documents 5.1.1 By international agreement, the theoretical tempera-
2
ture scale to which all temperature values should be ultimately
2.1 ASTM Standards:
referable is the Kelvin Thermodynamic Temperature Scale
E344 Terminology Relating to Thermometry and Hydrom-
(KTTS). A value of temperature expressed on the KTTS is
etry
known as a thermodynamic temperature, symbol T.
IEEE/ASTM SI-10 Standard for Use of the International
5.1.2 The unit of thermodynamic temperature is the kelvin,
System of Units (SI): The Modern Metric System
symbolK.ThekelvinisabaseunitintheInternationalSystem
3. Terminology
of Units (SI).
3.1 General—Standard terms used in this guide are defined
NOTE 1—The symbol for the kelvin is the capital letter K only; the
in Terminology E344 and in IEEE/ASTM SI-10.
degree sign (°) is not used.
5.1.3 The expression of a value of thermodynamic tempera-
4. Basic Concepts
ture is written:
4.1 Temperature is a fundamental measurable quantity des-
T 5 n K (1)
k
ignated by the symbol T or the symbol t (see 5.1). In
expressions of dimensions the symbol u is sometimes used to
where:
indicate the dimension temperature.
n = a numerical value designating the magnitude,
k
4.2 Atemperature value is expressed in terms of a tempera-
K = the symbol for the unit kelvin.
ture scale. The complete description consists of a numerical
value designating the magnitude, a unit, and, where appropri-
The magnitude may also be represented by the notation T/K.
ate, a tolerance or uncertainty. Both the numerical value and
5.1.4 Athermodynamic temperature may be expressed as a
unit depend upon the scale.
Celsius temperature. The symbol t is to be used to designate a
4.3 Aunit of temperature is understood to mean an interval
Celsius temperature, but if this symbol leads to a conflict in
on a temperature scale.
notation in a given context, it is acceptable to use the symbol
T instead to designate a Celsius temperature.
5.1.5 The unit of Celsius temperature is the degree Celsius,
1
This guide is under the jurisdiction ofASTM Committee E20 on Temperature
symbol °C. The degree Celsius is a derived SI unit.
Measurement and is the direct responsibility of Subcommittee E20.91 on Editorial
and Terminology.
NOTE 2—The symbol for the degree Celsius consists of the degree sign
Current edition approved Nov. 1, 2006. Published December 2006. Originally
(°) followed by the capital letter C. Neither the degree sign nor the letter
approved in 1994. Last previous edition approved in 1999 as E1594–99. DOI:
C alone represents the degree Celsius.
10.1520/E1594-06.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.1.6 The expression of a value of Celsius temperature is
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
written:
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. t 5 n °C (2)
c
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
E1594–06
Provisional Low-Temperature Scale from 0.9 mK to1Kis
where:
abbreviated PLTS-2000.
n = a numerical value designating the magnitude,
c
°C = the symbol for the unit degree Celsius. 6.1.3 Scale identification may be placed in text, in foot-
notes, in table headings, or in figures, as appropriate.
The magnitude may also be represented by the notation t/°C. 6.1.4 A scale may also be identified by a subscript associ-
5.1.7 Bydefinition,atanytemperature,atemperatureincre- ated with a quantity symbol; for example, T and t for
Th Th
mentofonedegreeCelsiusisequaltoatemperatureincrement thermodynamic temperatures and T and t for temperature
90 90
of one kelvin. values on ITS-90.
5.1.8 By definition, the Celsius temperature t=0 °C is the 6.2 Numerical Format:
same as the thermodynamic temperature T =273.15 K. The
6.2.1 Numerical values of temperature should be expressed
relationbetweennumericalva
...
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