ASTM E220-07e1
(Test Method)Standard Test Method for Calibration of Thermocouples By Comparison Techniques
Standard Test Method for Calibration of Thermocouples By Comparison Techniques
SIGNIFICANCE AND USE
For users or manufacturers of thermocouples, this test method provides a means of verifying the emf-temperature characteristics of the material prior to use.
This test method can be used to calibrate a thermocouple for use as a reference, or it can be used to calibrate thermocouples representing a batch of purchased, assembled thermocouples.
This test method can be used for the verification of the conformance of thermocouple materials to temperature tolerances for specifications such as the tables in Specification E 230 or other special specifications as required for commercial, military, or research applications.
SCOPE
1.1 This test method describes the principles, apparatus, and procedure for calibrating thermocouples by comparison with a reference thermometer. Calibrations are covered over temperature ranges appropriate to the individual types of thermocouples within an overall range from approximately 195 to 1700 °C (320 to 3100 F).
1.2 In general, this test method is applicable to unused thermocouples. This test method does not apply to used thermocouples due to their potential material inhomogeneity-the effects of which cannot be identified or quantified by standard calibration techniques. Thermocouples with large-diameter thermoelements and sheathed thermocouples may require special care to control thermal conduction losses.
1.3 In this test method, all values of temperature are based on the International Temperature Scale of 1990. See Guide E 1594.
This standard may involve hazardous materials, operations and equipment. 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 and health practices and determine the applicability of regulatory requirements prior to use.
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Standards Content (Sample)
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Designation:E220–07
Standard Test Method for
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Calibration of Thermocouples By Comparison Techniques
This standard is issued under the fixed designation E220; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
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e NOTE—Editorial changes were made throughout in July 2007.
1. Scope E344 Terminology Relating to Thermometry and Hydrom-
etry
1.1 Thistestmethoddescribestheprinciples,apparatus,and
E452 Test Method for Calibration of Refractory Metal
procedure for calibrating thermocouples by comparison with a
Thermocouples Using a Radiation Thermometer
referencethermometer.Calibrationsarecoveredovertempera-
E563 PracticeforPreparationandUseofanIce-PointBath
ture ranges appropriate to the individual types of thermo-
as a Reference Temperature
couples within an overall range from approximately −195 to
E644 Test Methods for Testing Industrial Resistance Ther-
1700 °C (−320 to 3100 °F).
mometers
1.2 In general, this test method is applicable to unused
E988 Temperature-Electromotive Force (EMF) Tables for
thermocouples. This test method does not apply to used
Tungsten-Rhenium Thermocouples
thermocouplesduetotheirpotentialmaterialinhomogeneity—
E1129/E1129M Specification for Thermocouple Connec-
the effects of which cannot be identified or quantified by
tors
standard calibration techniques. Thermocouples with large-
E1594 Guide for Expression of Temperature
diameter thermoelements and sheathed thermocouples may
E1684 Specification for Miniature Thermocouple Connec-
require special care to control thermal conduction losses.
tors
1.3 In this test method, all values of temperature are based
E1751 Guide for Temperature Electromotive Force (EMF)
on the International Temperature Scale of 1990. See Guide
Tables for Non-Letter Designated Thermocouple Combi-
E1594.
nations
1.4 This standard may involve hazardous materials, opera-
tions and equipment. This standard does not purport to address
3. Terminology
all of the safety concerns, if any, associated with its use. It is
3.1 Definitions—The definitions given in Terminology
the responsibility of the user of this standard to establish
E344 shall apply to this test method.
appropriate safety and health practices and determine the
3.2 Definitions of Terms Specific to This Standard:
applicability of regulatory requirements prior to use.
3.2.1 check standard, n—a measurement instrument or
2. Referenced Documents standard whose repeated results of measurement are used to
2 determine the repeatability of a calibration process and to
2.1 ASTM Standards:
verifythattheresultsofacalibrationprocessesarestatistically
E1 Specification forASTM Liquid-in-GlassThermometers
consistent with past results.
E77 Test Method for Inspection and Verification of Ther-
3.2.2 isothermal block, n—a piece of solid material of high
mometers
thermal conductivity used to promote thermal equilibrium
E230 Specification and Temperature-Electromotive Force
between two or more thermometers.
(EMF) Tables for Standardized Thermocouples
3.2.3 reference junction compensation, n—the adjustment
of the indication of a thermocouple such that the adjusted
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This test method is under the jurisdiction of ASTM Committee E20 on indication is equivalent to the emf or temperature that the
Temperature Measurement and is the direct responsibility of Subcommittee E20.04
thermocouple would indicate if the reference junctions were
on Thermocouples.
maintained at 0 °C.
Current edition approved May 1, 2007. Published June 2007. Originally
3.2.3.1 Discussion—In most cases, the thermocouple indi-
approved in 1963. Last previous edition approved in 2002 as E220–02.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cation is adjusted by measuring the temperature of a terminal
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
blockwherethethermocoupleisconnected,andthenaddingto
Standards volume information, refer to the standard’s Document Summary page on
thethermocoupleemfanadditionalemfequaltotheemfofthe
the ASTM website.
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E220–07
thermocouple reference function evaluated at the temperature are acceptable temperature comparison environments. In the
of the terminal block. Because the emf-temperature relation- case of large diameter thermoelements and sheathed thermo-
shipofanyactualthermocouplediffersslightlyfromthatofthe couples, special atte
...
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