ASTM E839-11(2016)e1
(Test Method)Standard Test Methods for Sheathed Thermocouples and Sheathed Thermocouple Cable
Standard Test Methods for Sheathed Thermocouples and Sheathed Thermocouple Cable
SIGNIFICANCE AND USE
5.1 This standard provides a description of test methods used in other ASTM specifications to establish certain acceptable limits for characteristics of thermocouple assemblies and thermocouple cable. These test methods define how those characteristics shall be determined.
5.2 The usefulness and purpose of the included tests are given for the category of tests.
5.3 Warning—Users should be aware that certain characteristics of thermocouples might change with time and use. If a thermocouple’s designed shipping, storage, installation, or operating temperature has been exceeded, that thermocouple’s moisture seal may have been compromised and may no longer adequately prevent the deleterious intrusion of water vapor. Consequently, the thermocouple’s condition established by test at the time of manufacture may not apply later. In addition, inhomogeneities can develop in thermoelements because of exposure to higher temperatures, even in cases where maximum exposure temperatures have been lower than the suggested upper use temperature limits specified in Table 1 of Specification E608/E608M. For this reason, calibration of thermocouples destined for delivery to a customer is not recommended. Because the EMF indication of any thermocouple depends upon the condition of the thermoelements along their entire length, as well as the temperature profile pattern in the region of any inhomogeneity, the EMF output of a used thermocouple will be unique to its installation. Because temperature profiles in calibration equipment are unlikely to duplicate those of the installation, removal of a used thermocouple to a separate apparatus for calibration is not recommended. Instead, in situ calibration by comparison to a similar thermocouple known to be good is often recommended.
SCOPE
1.1 This document lists methods for testing Mineral-Insulated, Metal-Sheathed (MIMS) thermocouple assemblies and thermocouple cable, but does not require that any of these tests be performed nor does it state criteria for acceptance. The acceptance criteria are given in other ASTM standard specifications that impose this testing for those thermocouples and cable. Examples from ASTM thermocouple specifications for acceptance criteria are given for many of the tests. These tabulated values are not necessarily those that would be required to meet these tests, but are included as examples only.
1.2 These tests are intended to support quality control and to evaluate the suitability of sheathed thermocouple cable or assemblies for specific applications. Some alternative test methods to obtain the same information are given, since in a given situation, an alternative test method may be more practical. Service conditions are widely variable, so it is unlikely that all the tests described will be appropriate for a given thermocouple application. A brief statement is made following each test description to indicate when it might be used.
1.3 The tests described herein include test methods to measure the following properties of sheathed thermocouple material and assemblies.
1.3.1 Insulation Properties:
1.3.1.1 Compaction—direct method, absorption method, and tension method.
1.3.1.2 Thickness.
1.3.1.3 Resistance—at room temperature and at elevated temperature.
1.3.2 Sheath Properties:
1.3.2.1 Integrity—two water test methods and mass spectrometer.
1.3.2.2 Dimensions—length, diameter, and roundness.
1.3.2.3 Wall thickness.
1.3.2.4 Surface—gross visual, finish, defect detection by dye penetrant, and cold-lap detection by tension test.
1.3.2.5 Metallurgical structure.
1.3.2.6 Ductility—bend test and tension test.
1.3.3 Thermoelement Properties:
1.3.3.1 Calibration.
1.3.3.2 Homogeneity.
1.3.3.3 Drift.
1.3.3.4 Thermoelement diameter, roundness, and surface appearance.
1.3.3.5 Thermoelement spacing.
1.3.3.6 Thermoelement ductility.
1.3.3.7 Metallurgical structure.
1.3.4 Thermocouple Assembly Prop...
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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.
´1
Designation: E839 − 11 (Reapproved 2016) An American National Standard
Standard Test Methods for
Sheathed Thermocouples and Sheathed Thermocouple
Cable
This standard is issued under the fixed designation E839; 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.
ε NOTE—Added references to Tables X1.7 and X1.8 to 10.7.4 editorially in December 2016.
1. Scope 1.3.2.2 Dimensions—length, diameter, and roundness.
1.3.2.3 Wall thickness.
1.1 This document lists methods for testing Mineral-
1.3.2.4 Surface—gross visual, finish, defect detection by
Insulated, Metal-Sheathed (MIMS) thermocouple assemblies
dye penetrant, and cold-lap detection by tension test.
and thermocouple cable, but does not require that any of these
1.3.2.5 Metallurgical structure.
testsbeperformednordoesitstatecriteriaforacceptance.The
acceptance criteria are given in other ASTM standard specifi- 1.3.2.6 Ductility—bend test and tension test.
cations that impose this testing for those thermocouples and 1.3.3 Thermoelement Properties:
cable. Examples from ASTM thermocouple specifications for
1.3.3.1 Calibration.
acceptance criteria are given for many of the tests. These
1.3.3.2 Homogeneity.
tabulated values are not necessarily those that would be
1.3.3.3 Drift.
requiredtomeetthesetests,butareincludedasexamplesonly.
1.3.3.4 Thermoelement diameter, roundness, and surface
appearance.
1.2 Thesetestsareintendedtosupportqualitycontrolandto
evaluate the suitability of sheathed thermocouple cable or 1.3.3.5 Thermoelement spacing.
assemblies for specific applications. Some alternative test
1.3.3.6 Thermoelement ductility.
methods to obtain the same information are given, since in a
1.3.3.7 Metallurgical structure.
given situation, an alternative test method may be more
1.3.4 Thermocouple Assembly Properties:
practical. Service conditions are widely variable, so it is
1.3.4.1 Dimensions—length, diameter, and roundness.
unlikely that all the tests described will be appropriate for a
1.3.4.2 Surface—gross visual, finish, reference junction end
given thermocouple application. A brief statement is made
moisture seal, and defect detection by dye penetrant.
following each test description to indicate when it might be
1.3.4.3 Electrical—continuity, loop resistance, and connec-
used.
tor polarity.
1.3 The tests described herein include test methods to
1.3.4.4 Radiographic inspection.
measure the following properties of sheathed thermocouple
1.3.4.5 Thermoelement diameter.
material and assemblies.
1.3.4.6 Thermal response time.
1.3.1 Insulation Properties:
1.3.4.7 Thermal cycle.
1.3.1.1 Compaction—direct method, absorption method,
1.4 The values stated in either SI units or inch-pound units
and tension method.
are to be regarded separately as standard. The values stated in
1.3.1.2 Thickness.
each system may not be exact equivalents; therefore, each
1.3.1.3 Resistance—at room temperature and at elevated
system shall be used independently of the other. Combining
temperature.
values from the two systems may result in non-conformance
1.3.2 Sheath Properties:
with the standard.
1.3.2.1 Integrity—two water test methods and mass spec-
trometer.
1.5 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 appro-
1 priate safety and health practices and determine the applica-
These test methods are under the jurisdiction of ASTM Committee E20 on
Temperature Measurement and is the direct responsibility of Subcommittee E20.14
bility of regulatory limitations prior to use.
on Thermocouples - Testing.
1.6 This international standard was developed in accor-
Current edition approved Nov. 1, 2011. Published January 2016. Originally
dance with internationally recognized principles on standard-
approved in 1989. Last previous edition approved in 2011 as E839–11. DOI:
10.1520/E0839-11R16E01. ization established in the Decision on Principles for the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E839 − 11 (2016)
Development of International Standards, Guides and Recom- 2.2 ANSI Standard
mendations issued by the World Trade Organization Technical B 46.1Surface Texture
Barriers to Trade (TBT) Committee.
2.3 Other Standard
USAEC Division of Reactor Development and Technology
2. Referenced Documents
RDTStandardC2-1TDeterminationofInsulationCom-
2 paction in Ceramic Insulated Conductors August 1970
2.1 ASTM Standards:
E3Guide for Preparation of Metallographic Specimens
3. Terminology
E94Guide for Radiographic Examination Using Industrial
3.1 Definitions—ThedefinitionsgiveninTerminologyE344
Radiographic Film
shall apply to these test methods.
E112Test Methods for Determining Average Grain Size
E165Practice for Liquid Penetrant Testing for General
3.2 Definitions of Terms Specific to This Standard:
Industry
3.2.1 bulk cable, n—a single length of thermocouple cable
E177Practice for Use of the Terms Precision and Bias in
produced from the same raw material lots after completion of
ASTM Test Methods
fabrication.
E207TestMethodforThermalEMFTestofSingleThermo-
3.2.2 cable lot, n—a quantity of finished mineral–insulated,
element Materials by Comparison with a Reference Ther-
metal-sheathed thermocouple cable manufactured from tubing
moelement of Similar EMF-Temperature Properties
or other sheath material from the same heat, wire from the
E220Test Method for Calibration of Thermocouples By
same spool and heat, and insulation from the same batch, then
Comparison Techniques
assembled and processed together under controlled production
E230Specification for Temperature-Electromotive Force
conditions to the required final outside diameter.
(emf) Tables for Standardized Thermocouples
3.2.3 cold-lap, n—sheath surface defect where the sheath
E235 Specification for Type K and Type N Mineral-
surface has been galled and torn by a drawing die and the torn
Insulated, Metal-Sheathed Thermocouples for Nuclear or
surface smoothed by a subsequent diameter reduction.
for Other High-Reliability Applications
3.2.4 insulation compaction density, n—the density of a
E344Terminology Relating to Thermometry and Hydrom-
compacted powder is the combined density of the powder
etry
particlesandthevoidsremainingafterthepowdercompaction.
E585/E585M Specification for Compacted Mineral-
Sometimes the insulation compaction density is divided by the
Insulated, Metal-Sheathed, Base Metal Thermocouple
theoretical density of the powder particles to obtain a dimen-
Cable
sionless fraction of theoretical density as a convenient method
E608/E608MSpecification for Mineral-Insulated, Metal-
to express the relative compaction.
Sheathed Base Metal Thermocouples
E691Practice for Conducting an Interlaboratory Study to
3.2.5 raw material, n—tubing or other sheath material,
Determine the Precision of a Test Method
insulation and wires used in the fabrication of sheathed
E780Test Method for Measuring the Insulation Resistance
thermocouple cable.
of Mineral-Insulated, Metal-SheathedThermocouples and
3.2.6 short range ordering, n—the reversible short-ranged,
Mineral-Insulated, Metal-Sheathed Cable at Room Tem-
order-disorder transformation in which the nickel and chro-
perature
mium atoms occupy specific (ordered) localized sites in the
E1025 Practice for Design, Manufacture, and Material
Type EP or Type KP thermoelement alloy crystal structure.
Grouping Classification of Hole-Type Image Quality In-
3.2.7 thermal response time, n—the time required for a
dicators (IQI) Used for Radiography
sheathed thermocouple signal to attain the specified percent of
E1129/E1129MSpecification for Thermocouple Connectors
the total voltage change produced by a step change of
E1350GuideforTestingSheathedThermocouples,Thermo-
temperature at the sheath’s outer surface.
couple Assemblies, and Connecting Wires Prior to, and
After Installation or Service
4. Summary of Test Methods
E1684Specification for Miniature Thermocouple Connec-
4.1 Insulation Properties:
tors
4.1.1 Compaction—These tests ensure that the insulation is
E1751Guide for Temperature Electromotive Force (emf)
compacted sufficiently (1) to prevent the insulation from
Tables for Non-Letter Designated Thermocouple Combi-
shifting during use with the possibility of the thermoelements
nations
shorting to each other or to the sheath, and (2) to have good
E2181/E2181M Specification for Compacted Mineral-
heat transfer between the sheath and the thermoelements.
Insulated, Metal-Sheathed, Noble Metal Thermocouples
4.1.2 Insulation Resistance—The insulation shall be free of
and Thermocouple Cable
moisture and contaminants that would compromise the
voltage-temperature relationship or shorten the useful life of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036.
´1
E839 − 11 (2016)
the sheathed thermocouple. Measurement of insulation resis- 5.2 The usefulness and purpose of the included tests are
tance is a useful way to detect the presence of unacceptable given for the category of tests.
levels of impurities in the insulation.
5.3 Warning—Users should be aware that certain charac-
4.2 Sheath Properties: teristics of thermocouples might change with time and use. If
a thermocouple’s designed shipping, storage, installation, or
4.2.1 Integrity—These tests ensure that (1) the sheath will
be impervious to moisture and gases so the insulation and operating temperature has been exceeded, that thermocouple’s
moisture seal may have been compromised and may no longer
thermoelements will be protected, (2) surface flaws and cracks
that might develop into sheath leaks are detected, and (3) the adequately prevent the deleterious intrusion of water vapor.
Consequently,thethermocouple’sconditionestablishedbytest
sheath walls are as thick as specified.
4.2.2 Dimensions—Determination of length, diameter, and at the time of manufacture may not apply later. In addition,
inhomogeneities can develop in thermoelements because of
sheath roundness are often necessary to assure proper dimen-
sional fit. exposure to higher temperatures, even in cases where maxi-
mum exposure temperatures have been lower than the sug-
4.2.3 Sheath Ductility—The sheath shall be ductile enough
gested upper use temperature limits specified in Table 1 of
to bend the required amount without breaking or cracking.
Specification E608/E608M. For this reason, calibration of
4.3 Thermoelement Properties Service Life:
thermocouples destined for delivery to a customer is not
4.3.1 Calibration—This test ensures that the temperature-
recommended. Because the EMF indication of any thermo-
emf relationship initially corresponds to standardized toler-
couple depends upon the condition of the thermoelements
ances.
along their entire length, as well as the temperature profile
4.3.2 Size—The thermocouple sheath and thermoelement
pattern in the region of any inhomogeneity, the EMF output of
sizes are related to the service life and the thermoelement
a used thermocouple will be unique to its installation. Because
spacing is related to possible low insulation resistance or
temperature profiles in calibration equipment are unlikely to
shorting.
duplicate those of the installation, removal of a used thermo-
4.3.3 Thermoelement Ductility—Ductility of the thermoele-
couple to a separate apparatus for calibration is not recom-
ments shall be sufficient to allow the assembly to be bent
mended. Instead, in situ calibration by comparison to a similar
during assembly or service without significant damage to the
thermocouple known to be good is often recommended.
thermoelements.
4.4 Thermocouple Assembly Properties—The criteria listed
6. General Requirements
aboveshallapplytoboththermocoupleassembliesandtobulk
6.1 All the inspection operations are to be performed under
cable. In addition, the following tests are important for
clean conditions that will not degrade the insulation, sheath, or
thermocouple assemblies.
thermoelements.This includes the use of suitable gloves when
4.4.1 Continuity—The loop continuity test assures that the
appropriate.
thermocouple assembly has a completed circuit.
6.2 During all process steps in which insulation is exposed
4.4.2 Loop Resistance—The loop resistance test can detect
to ambient atmosphere, the air shall be clean, with less than
shorted or damaged thermoelements.
50% relative humidity, and at a temperature between 20 and
4.4.3 Polarity—The connector polarity test indicates
26°C (68 and 79°F).
whether the connector is correctly installed.
4.4.4 Moisture Seal—The moisture seal at the reference
6.3 All samples which are tested shall be identified by
junction end of the thermocouple, if faulty, may allow con-
material code, and shall be traceable to a production run.
tamination of the insulation with moisture or gases.
4.4.5 Radiography—Radiographic examination of the junc-
7. Insulation Properties
tion and sheath closure weld can indicate faulty junctions and
7.1 Insulation Compaction Density—The thermal conduc-
sheath closures that will lead to early failure. Most internal
tivityoftheinsulation,aswellastheabilityoftheinsulationto
dimensions can also be measured from the radiograph.
lock the thermoelements into place, will be affected by the
4.4.6 Response Time—The thermal response time gives an
insulation compaction density.
indication of the quickness with which an installed thermo-
7.1.1 Adirect method for measuring insulation compaction
couple will signal a changing temperature under the test
density is applicable if a representative sample can be sec-
conditions.
tioned so that the sample ends are perpendicular to the sample
4.4.7 Thermal Cycle—The thermal cycle test will offer
length and the sheath, thermoelements, and insulation form a
assurance that the thermocouple will not have early failure
smooth surface free of burrs. The procedure is as follows:
because of strains imposed from temperature transients.
7.1.1.1 Weigh the sample section,
7.1.1.2 Measure the sheath diameter and length with a
5. Significance and Use
microme
...
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: E839 − 11 (Reapproved 2016) An American National Standard
Standard Test Methods for
Sheathed Thermocouples and Sheathed Thermocouple
Cable
This standard is issued under the fixed designation E839; 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.
ε NOTE—Added references to Tables X1.7 and X1.8 to 10.7.4 editorially in December 2016.
1. Scope 1.3.2.2 Dimensions—length, diameter, and roundness.
1.3.2.3 Wall thickness.
1.1 This document lists methods for testing Mineral-
1.3.2.4 Surface—gross visual, finish, defect detection by
Insulated, Metal-Sheathed (MIMS) thermocouple assemblies
dye penetrant, and cold-lap detection by tension test.
and thermocouple cable, but does not require that any of these
1.3.2.5 Metallurgical structure.
tests be performed nor does it state criteria for acceptance. The
1.3.2.6 Ductility—bend test and tension test.
acceptance criteria are given in other ASTM standard specifi-
cations that impose this testing for those thermocouples and 1.3.3 Thermoelement Properties:
cable. Examples from ASTM thermocouple specifications for
1.3.3.1 Calibration.
acceptance criteria are given for many of the tests. These
1.3.3.2 Homogeneity.
tabulated values are not necessarily those that would be
1.3.3.3 Drift.
required to meet these tests, but are included as examples only.
1.3.3.4 Thermoelement diameter, roundness, and surface
appearance.
1.2 These tests are intended to support quality control and to
evaluate the suitability of sheathed thermocouple cable or 1.3.3.5 Thermoelement spacing.
assemblies for specific applications. Some alternative test 1.3.3.6 Thermoelement ductility.
methods to obtain the same information are given, since in a
1.3.3.7 Metallurgical structure.
given situation, an alternative test method may be more
1.3.4 Thermocouple Assembly Properties:
practical. Service conditions are widely variable, so it is
1.3.4.1 Dimensions—length, diameter, and roundness.
unlikely that all the tests described will be appropriate for a
1.3.4.2 Surface—gross visual, finish, reference junction end
given thermocouple application. A brief statement is made
moisture seal, and defect detection by dye penetrant.
following each test description to indicate when it might be
1.3.4.3 Electrical—continuity, loop resistance, and connec-
used.
tor polarity.
1.3 The tests described herein include test methods to
1.3.4.4 Radiographic inspection.
measure the following properties of sheathed thermocouple
1.3.4.5 Thermoelement diameter.
material and assemblies.
1.3.4.6 Thermal response time.
1.3.1 Insulation Properties:
1.3.4.7 Thermal cycle.
1.3.1.1 Compaction—direct method, absorption method,
1.4 The values stated in either SI units or inch-pound units
and tension method.
are to be regarded separately as standard. The values stated in
1.3.1.2 Thickness.
each system may not be exact equivalents; therefore, each
1.3.1.3 Resistance—at room temperature and at elevated
system shall be used independently of the other. Combining
temperature.
values from the two systems may result in non-conformance
1.3.2 Sheath Properties:
with the standard.
1.3.2.1 Integrity—two water test methods and mass spec-
trometer.
1.5 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 appro-
priate safety and health practices and determine the applica-
These test methods are under the jurisdiction of ASTM Committee E20 on
Temperature Measurement and is the direct responsibility of Subcommittee E20.14 bility of regulatory limitations prior to use.
on Thermocouples - Testing.
1.6 This international standard was developed in accor-
Current edition approved Nov. 1, 2011. Published January 2016. Originally
dance with internationally recognized principles on standard-
approved in 1989. Last previous edition approved in 2011 as E839 – 11. DOI:
10.1520/E0839-11R16E01. ization established in the Decision on Principles for the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E839 − 11 (2016)
Development of International Standards, Guides and Recom- 2.2 ANSI Standard
B 46.1 Surface Texture
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2.3 Other Standard
USAEC Division of Reactor Development and Technology
2. Referenced Documents
RDT Standard C 2-1T Determination of Insulation Com-
2 paction in Ceramic Insulated Conductors August 1970
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
3. Terminology
E94 Guide for Radiographic Examination Using Industrial
Radiographic Film 3.1 Definitions—The definitions given in Terminology E344
shall apply to these test methods.
E112 Test Methods for Determining Average Grain Size
E165 Practice for Liquid Penetrant Testing for General
3.2 Definitions of Terms Specific to This Standard:
Industry
3.2.1 bulk cable, n—a single length of thermocouple cable
E177 Practice for Use of the Terms Precision and Bias in
produced from the same raw material lots after completion of
ASTM Test Methods
fabrication.
E207 Test Method for Thermal EMF Test of Single Thermo-
3.2.2 cable lot, n—a quantity of finished mineral–insulated,
element Materials by Comparison with a Reference Ther-
metal-sheathed thermocouple cable manufactured from tubing
moelement of Similar EMF-Temperature Properties
or other sheath material from the same heat, wire from the
E220 Test Method for Calibration of Thermocouples By
same spool and heat, and insulation from the same batch, then
Comparison Techniques
assembled and processed together under controlled production
E230 Specification for Temperature-Electromotive Force
conditions to the required final outside diameter.
(emf) Tables for Standardized Thermocouples
3.2.3 cold-lap, n—sheath surface defect where the sheath
E235 Specification for Type K and Type N Mineral-
surface has been galled and torn by a drawing die and the torn
Insulated, Metal-Sheathed Thermocouples for Nuclear or
surface smoothed by a subsequent diameter reduction.
for Other High-Reliability Applications
3.2.4 insulation compaction density, n—the density of a
E344 Terminology Relating to Thermometry and Hydrom-
compacted powder is the combined density of the powder
etry
particles and the voids remaining after the powder compaction.
E585/E585M Specification for Compacted Mineral-
Sometimes the insulation compaction density is divided by the
Insulated, Metal-Sheathed, Base Metal Thermocouple
theoretical density of the powder particles to obtain a dimen-
Cable
sionless fraction of theoretical density as a convenient method
E608/E608M Specification for Mineral-Insulated, Metal-
to express the relative compaction.
Sheathed Base Metal Thermocouples
E691 Practice for Conducting an Interlaboratory Study to
3.2.5 raw material, n—tubing or other sheath material,
Determine the Precision of a Test Method
insulation and wires used in the fabrication of sheathed
E780 Test Method for Measuring the Insulation Resistance
thermocouple cable.
of Mineral-Insulated, Metal-Sheathed Thermocouples and
3.2.6 short range ordering, n—the reversible short-ranged,
Mineral-Insulated, Metal-Sheathed Cable at Room Tem-
order-disorder transformation in which the nickel and chro-
perature
mium atoms occupy specific (ordered) localized sites in the
E1025 Practice for Design, Manufacture, and Material
Type EP or Type KP thermoelement alloy crystal structure.
Grouping Classification of Hole-Type Image Quality In-
3.2.7 thermal response time, n—the time required for a
dicators (IQI) Used for Radiography
sheathed thermocouple signal to attain the specified percent of
E1129/E1129M Specification for Thermocouple Connectors
the total voltage change produced by a step change of
E1350 Guide for Testing Sheathed Thermocouples, Thermo-
temperature at the sheath’s outer surface.
couple Assemblies, and Connecting Wires Prior to, and
After Installation or Service
4. Summary of Test Methods
E1684 Specification for Miniature Thermocouple Connec-
4.1 Insulation Properties:
tors
4.1.1 Compaction—These tests ensure that the insulation is
E1751 Guide for Temperature Electromotive Force (emf)
compacted sufficiently (1) to prevent the insulation from
Tables for Non-Letter Designated Thermocouple Combi-
shifting during use with the possibility of the thermoelements
nations
shorting to each other or to the sheath, and (2) to have good
E2181/E2181M Specification for Compacted Mineral-
heat transfer between the sheath and the thermoelements.
Insulated, Metal-Sheathed, Noble Metal Thermocouples
4.1.2 Insulation Resistance—The insulation shall be free of
and Thermocouple Cable
moisture and contaminants that would compromise the
voltage-temperature relationship or shorten the useful life of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036.
´1
E839 − 11 (2016)
the sheathed thermocouple. Measurement of insulation resis- 5.2 The usefulness and purpose of the included tests are
tance is a useful way to detect the presence of unacceptable given for the category of tests.
levels of impurities in the insulation.
5.3 Warning—Users should be aware that certain charac-
4.2 Sheath Properties: teristics of thermocouples might change with time and use. If
4.2.1 Integrity—These tests ensure that (1) the sheath will a thermocouple’s designed shipping, storage, installation, or
operating temperature has been exceeded, that thermocouple’s
be impervious to moisture and gases so the insulation and
thermoelements will be protected, (2) surface flaws and cracks moisture seal may have been compromised and may no longer
adequately prevent the deleterious intrusion of water vapor.
that might develop into sheath leaks are detected, and (3) the
sheath walls are as thick as specified. Consequently, the thermocouple’s condition established by test
at the time of manufacture may not apply later. In addition,
4.2.2 Dimensions—Determination of length, diameter, and
sheath roundness are often necessary to assure proper dimen- inhomogeneities can develop in thermoelements because of
exposure to higher temperatures, even in cases where maxi-
sional fit.
4.2.3 Sheath Ductility—The sheath shall be ductile enough mum exposure temperatures have been lower than the sug-
gested upper use temperature limits specified in Table 1 of
to bend the required amount without breaking or cracking.
Specification E608/E608M. For this reason, calibration of
4.3 Thermoelement Properties Service Life:
thermocouples destined for delivery to a customer is not
4.3.1 Calibration—This test ensures that the temperature-
recommended. Because the EMF indication of any thermo-
emf relationship initially corresponds to standardized toler-
couple depends upon the condition of the thermoelements
ances.
along their entire length, as well as the temperature profile
4.3.2 Size—The thermocouple sheath and thermoelement
pattern in the region of any inhomogeneity, the EMF output of
sizes are related to the service life and the thermoelement
a used thermocouple will be unique to its installation. Because
spacing is related to possible low insulation resistance or
temperature profiles in calibration equipment are unlikely to
shorting.
duplicate those of the installation, removal of a used thermo-
4.3.3 Thermoelement Ductility—Ductility of the thermoele-
couple to a separate apparatus for calibration is not recom-
ments shall be sufficient to allow the assembly to be bent
mended. Instead, in situ calibration by comparison to a similar
during assembly or service without significant damage to the
thermocouple known to be good is often recommended.
thermoelements.
4.4 Thermocouple Assembly Properties—The criteria listed
6. General Requirements
above shall apply to both thermocouple assemblies and to bulk
6.1 All the inspection operations are to be performed under
cable. In addition, the following tests are important for
clean conditions that will not degrade the insulation, sheath, or
thermocouple assemblies.
thermoelements. This includes the use of suitable gloves when
4.4.1 Continuity—The loop continuity test assures that the
appropriate.
thermocouple assembly has a completed circuit.
6.2 During all process steps in which insulation is exposed
4.4.2 Loop Resistance—The loop resistance test can detect
to ambient atmosphere, the air shall be clean, with less than
shorted or damaged thermoelements.
50 % relative humidity, and at a temperature between 20 and
4.4.3 Polarity—The connector polarity test indicates
26°C (68 and 79°F).
whether the connector is correctly installed.
4.4.4 Moisture Seal—The moisture seal at the reference
6.3 All samples which are tested shall be identified by
junction end of the thermocouple, if faulty, may allow con-
material code, and shall be traceable to a production run.
tamination of the insulation with moisture or gases.
4.4.5 Radiography—Radiographic examination of the junc-
7. Insulation Properties
tion and sheath closure weld can indicate faulty junctions and
7.1 Insulation Compaction Density—The thermal conduc-
sheath closures that will lead to early failure. Most internal
tivity of the insulation, as well as the ability of the insulation to
dimensions can also be measured from the radiograph.
lock the thermoelements into place, will be affected by the
4.4.6 Response Time—The thermal response time gives an
insulation compaction density.
indication of the quickness with which an installed thermo-
7.1.1 A direct method for measuring insulation compaction
couple will signal a changing temperature under the test
density is applicable if a representative sample can be sec-
conditions.
tioned so that the sample ends are perpendicular to the sample
4.4.7 Thermal Cycle—The thermal cycle test will offer
length and the sheath, thermoelements, and insulation form a
assurance that the thermocouple will not have early failure
smooth surface free of burrs. The procedure is as follows:
because of strains imposed from temperature transients.
7.1.1.1 Weigh the sample section,
7.1.1.2 Measure the sheath diameter and length with a
5. Significance and Use
micrometer,
7.1.
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
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Designation: E839 − 11 (Reapproved 2016) E839 − 11 (Reapproved 2016)
Standard Test Methods for
Sheathed Thermocouples and Sheathed Thermocouple
Cable
This standard is issued under the fixed designation E839; 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.
ε NOTE—Added references to Tables X1.7 and X1.8 to 10.7.4 editorially in December 2016.
1. Scope
1.1 This document lists methods for testing Mineral-Insulated, Metal-Sheathed (MIMS) thermocouple assemblies and
thermocouple cable, but does not require that any of these tests be performed nor does it state criteria for acceptance. The
acceptance criteria are given in other ASTM standard specifications that impose this testing for those thermocouples and cable.
Examples from ASTM thermocouple specifications for acceptance criteria are given for many of the tests. These tabulated values
are not necessarily those that would be required to meet these tests, but are included as examples only.
1.2 These tests are intended to support quality control and to evaluate the suitability of sheathed thermocouple cable or
assemblies for specific applications. Some alternative test methods to obtain the same information are given, since in a given
situation, an alternative test method may be more practical. Service conditions are widely variable, so it is unlikely that all the tests
described will be appropriate for a given thermocouple application. A brief statement is made following each test description to
indicate when it might be used.
1.3 The tests described herein include test methods to measure the following properties of sheathed thermocouple material and
assemblies.
1.3.1 Insulation Properties:
1.3.1.1 Compaction—direct method, absorption method, and tension method.
1.3.1.2 Thickness.
1.3.1.3 Resistance—at room temperature and at elevated temperature.
1.3.2 Sheath Properties:
1.3.2.1 Integrity—two water test methods and mass spectrometer.
1.3.2.2 Dimensions—length, diameter, and roundness.
1.3.2.3 Wall thickness.
1.3.2.4 Surface—gross visual, finish, defect detection by dye penetrant, and cold-lap detection by tension test.
1.3.2.5 Metallurgical structure.
1.3.2.6 Ductility—bend test and tension test.
1.3.3 Thermoelement Properties:
1.3.3.1 Calibration.
1.3.3.2 Homogeneity.
1.3.3.3 Drift.
1.3.3.4 Thermoelement diameter, roundness, and surface appearance.
1.3.3.5 Thermoelement spacing.
1.3.3.6 Thermoelement ductility.
1.3.3.7 Metallurgical structure.
1.3.4 Thermocouple Assembly Properties:
1.3.4.1 Dimensions—length, diameter, and roundness.
1.3.4.2 Surface—gross visual, finish, reference junction end moisture seal, and defect detection by dye penetrant.
1.3.4.3 Electrical—continuity, loop resistance, and connector polarity.
These test methods are under the jurisdiction of ASTM Committee E20 on Temperature Measurement and is the direct responsibility of Subcommittee E20.04 on
Thermocouples.
Current edition approved Nov. 1, 2016Nov. 1, 2011. Published January 2016. Originally approved in 1989. Last previous edition approved in 2011 as E839 – 11. DOI:
10.1520/E0839-11R16.10.1520/E0839-11R16E01.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E839 − 11 (2016)
1.3.4.4 Radiographic inspection.
1.3.4.5 Thermoelement diameter.
1.3.4.6 Thermal response time.
1.3.4.7 Thermal cycle.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.5 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
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
E94 Guide for Radiographic Examination
E112 Test Methods for Determining Average Grain Size
E165 Practice for Liquid Penetrant Examination for General Industry
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E207 Test Method for Thermal EMF Test of Single Thermoelement Materials by Comparison with a Reference Thermoelement
of Similar EMF-Temperature Properties
E220 Test Method for Calibration of Thermocouples By Comparison Techniques
E230 Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples
E235 Specification for Thermocouples, Sheathed, Type K and Type N, for Nuclear or for Other High-Reliability Applications
E344 Terminology Relating to Thermometry and Hydrometry
E585/E585M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Base Metal Thermocouple Cable
E608/E608M Specification for Mineral-Insulated, Metal-Sheathed Base Metal Thermocouples
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E780 Test Method for Measuring the Insulation Resistance of Mineral-Insulated, Metal-Sheathed Thermocouples and
Thermocouple Cable at Room Temperature
E1025 Practice for Design, Manufacture, and Material Grouping Classification of Hole-Type Image Quality Indicators (IQI)
Used for Radiology
E1129/E1129M Specification for Thermocouple Connectors
E1350 Guide for Testing Sheathed Thermocouples, Thermocouples Assemblies, and Connecting Wires Prior to, and After
Installation or Service
E1684 Specification for Miniature Thermocouple Connectors
E1751 Guide for Temperature Electromotive Force (EMF) Tables for Non-Letter Designated Thermocouple Combinations
(Withdrawn 2009)
E2181/E2181M Specification for Compacted Mineral-Insulated, Metal-Sheathed, Noble Metal Thermocouples and Thermo-
couple Cable
2.2 ANSI Standard
B 46.1 Surface Texture
2.3 Other Standard
USAEC Division of Reactor Development and Technology RDT Standard C 2-1T Determination of Insulation Compaction in
Ceramic Insulated Conductors August 1970
3. Terminology
3.1 Definitions—The definitions given in Terminology E344 shall apply to these test methods.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 bulk cable, n—a single length of thermocouple cable produced from the same raw material lots after completion of
fabrication.
3.2.2 cable lot, n—a quantity of finished mineral–insulated, metal-sheathed thermocouple cable manufactured from tubing or
other sheath material from the same heat, wire from the same spool and heat, and insulation from the same batch, then assembled
and processed together under controlled production conditions to the required final outside diameter.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.
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E839 − 11 (2016)
3.2.3 cold-lap, n—sheath surface defect where the sheath surface has been galled and torn by a drawing die and the torn surface
smoothed by a subsequent diameter reduction.
3.2.4 insulation compaction density, n—the density of a compacted powder is the combined density of the powder particles and
the voids remaining after the powder compaction. Sometimes the insulation compaction density is divided by the theoretical
density of the powder particles to obtain a dimensionless fraction of theoretical density as a convenient method to express the
relative compaction.
3.2.5 raw material, n—tubing or other sheath material, insulation and wires used in the fabrication of sheathed thermocouple
cable.
3.2.6 short range ordering, n—the reversible short-ranged, order-disorder transformation in which the nickel and chromium
atoms occupy specific (ordered) localized sites in the Type EP or Type KP thermoelement alloy crystal structure.
3.2.7 thermal response time, n—the time required for a sheathed thermocouple signal to attain the specified percent of the total
voltage change produced by a step change of temperature at the sheath’s outer surface.
4. Summary of Test Methods
4.1 Insulation Properties:
4.1.1 Compaction—These tests ensure that the insulation is compacted sufficiently (1) to prevent the insulation from shifting
during use with the possibility of the thermoelements shorting to each other or to the sheath, and (2) to have good heat transfer
between the sheath and the thermoelements.
4.1.2 Insulation Resistance—The insulation shall be free of moisture and contaminants that would compromise the
voltage-temperature relationship or shorten the useful life of the sheathed thermocouple. Measurement of insulation resistance is
a useful way to detect the presence of unacceptable levels of impurities in the insulation.
4.2 Sheath Properties:
4.2.1 Integrity—These tests ensure that (1) the sheath will be impervious to moisture and gases so the insulation and
thermoelements will be protected, (2) surface flaws and cracks that might develop into sheath leaks are detected, and (3) the sheath
walls are as thick as specified.
4.2.2 Dimensions—Determination of length, diameter, and sheath roundness are often necessary to assure proper dimensional
fit.
4.2.3 Sheath Ductility—The sheath shall be ductile enough to bend the required amount without breaking or cracking.
4.3 Thermoelement Properties Service Life:
4.3.1 Calibration—This test ensures that the temperature-emf relationship initially corresponds to standardized tolerances.
4.3.2 Size—The thermocouple sheath and thermoelement sizes are related to the service life and the thermoelement spacing is
related to possible low insulation resistance or shorting.
4.3.3 Thermoelement Ductility—Ductility of the thermoelements shall be sufficient to allow the assembly to be bent during
assembly or service without significant damage to the thermoelements.
4.4 Thermocouple Assembly Properties—The criteria listed above shall apply to both thermocouple assemblies and to bulk
cable. In addition, the following tests are important for thermocouple assemblies.
4.4.1 Continuity—The loop continuity test assures that the thermocouple assembly has a completed circuit.
4.4.2 Loop Resistance—The loop resistance test can detect shorted or damaged thermoelements.
4.4.3 Polarity—The connector polarity test indicates whether the connector is correctly installed.
4.4.4 Moisture Seal—The moisture seal at the reference junction end of the thermocouple, if faulty, may allow contamination
of the insulation with moisture or gases.
4.4.5 Radiography—Radiographic examination of the junction and sheath closure weld can indicate faulty junctions and sheath
closures that will lead to early failure. Most internal dimensions can also be measured from the radiograph.
4.4.6 Response Time—The thermal response time gives an indication of the quickness with which an installed thermocouple will
signal a changing temperature under the test conditions.
4.4.7 Thermal Cycle—The thermal cycle test will offer assurance that the thermocouple will not have early failure because of
strains imposed from temperature transients.
5. Significance and Use
5.1 This standard provides a description of test methods used in other ASTM specifications to establish certain acceptable limits
for characteristics of thermocouple assemblies and thermocouple cable. These test methods define how those characteristics shall
be determined.
5.2 The usefulness and purpose of the included tests are given for the category of tests.
5.3 Warning—Users should be aware that certain characteristics of thermocouples might change with time and use. If a
thermocouple’s designed shipping, storage, installation, or operating temperature has been exceeded, that thermocouple’s moisture
seal may have been compromised and may no longer adequately prevent the deleterious intrusion of water vapor. Consequently,
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E839 − 11 (2016)
the thermocouple’s condition established by test at the time of manufacture may not apply later. In addition, inhomogeneities can
develop in thermoelements because of exposure to higher temperatures, even in cases where maximum exposure temperatures have
been lower than the suggested upper use temperature limits specified in Table 1 of Specification E608/E608M. For this reason,
calibration of thermocouples destined for delivery to a customer is not recommended. Because the EMF indication of any
thermocouple depends upon the condition of the thermoelements along their entire length, as well as the temperature profile pattern
in the region of any inhomogeneity, the EMF output of a used thermocouple will be unique to its installation. Because temperature
profiles in calibration equipment are unlikely to duplicate those of the installation, removal of a used thermocouple to a separate
apparatus for calibration is not recommended. Instead, in situ calibration by comparison to a similar thermocouple known to be
good is often recommended.
6. General Requirements
6.1 All the inspection operations are to be performed under clean conditions that will not degrade the insulation, sheath, or
thermoelements. This includes the use of suitable gloves when appropriate.
6.2 During all process steps in which insulation is exposed to ambient atmosphere, the air shall be clean, with less than 50 %
relative humidity, and at a temperature between 20 and 26°C (68 and 79°F).
6.3 All samples which are tested shall be identified by material code, and shall be traceable to a production run.
7. Insulation Properties
7.1 Insulation Compaction Density—The thermal conductivity of the insulation, as well as the ability of the insulation to lock
the thermoelements into place, will be affected by the insulation compaction density.
7.1.1 A direct method for measuring insulation compaction density is applicable if a representative sample can be sectioned so
that the sample ends a
...
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