ASTM E696-07(2013)
(Specification)Standard Specification for Tungsten-Rhenium Alloy Thermocouple Wire
Standard Specification for Tungsten-Rhenium Alloy Thermocouple Wire
ABSTRACT
This specification covers the requirements for bare solid conductors made of tungsten and rhenium alloy thermoelements supplied in matched pairs. These thermoelements shall be suitable for use in either bead-insulated, bare-wire thermocouples, or in compacted metal-sheathed, ceramic insulated thermocouple material or assemblies. Unless otherwise noted, all information in this specification applies to both thermocouple combinations of tungsten-3 % rhenium versus tungsten-25 % rhenium (W3Re/W25Re) and tungsten-5 % rhenium versus tungsten-26 % rhenium (W5Re/W26Re; Type C). Thermoelements should meet specified physical, mechanical, thermoelectric, and compositional requirements.
SCOPE
1.1 This specification covers the requirements for bare, solid conductor, tungsten and rhenium alloy thermoelements having diameters of 0.127 mm (0.005 in.) to 0.508 mm (0.020 in.) supplied in matched pairs. These thermoelements shall be suitable for use either in bead-insulated, bare-wire thermocouples, or in compacted metal-sheathed, ceramic insulated thermocouple material or assemblies.
1.2 This specification covers the thermocouple combinations of tungsten-3 % rhenium versus tungsten-25 % rhenium (W3Re/W25Re) and tungsten-5 % rhenium versus tungsten-26 % rhenium (W5Re/W26Re; Type C). All information applies to both combinations unless otherwise noted.
1.3 It is recognized that the alloys described are refractory and are not suitable for use at high temperatures in oxidizing atmospheres. All tests and processes described herein must be performed under conditions that are non-reactive to tungsten-rhenium alloys.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
Designation:E696 −07 (Reapproved 2013)
Standard Specification for
Tungsten-Rhenium Alloy Thermocouple Wire
This standard is issued under the fixed designation E696; 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 moelement of Similar EMF-Temperature Properties
E220 Test Method for Calibration of Thermocouples By
1.1 This specification covers the requirements for bare,
Comparison Techniques
solid conductor, tungsten and rhenium alloy thermoelements
E230 Specification and Temperature-Electromotive Force
having diameters of 0.127 mm (0.005 in.) to 0.508 mm (0.020
(EMF) Tables for Standardized Thermocouples
in.) supplied in matched pairs. These thermoelements shall be
E344 Terminology Relating to Thermometry and Hydrom-
suitable for use either in bead-insulated, bare-wire
etry
thermocouples, or in compacted metal-sheathed, ceramic insu-
E452 Test Method for Calibration of Refractory Metal Ther-
lated thermocouple material or assemblies.
mocouples Using a Radiation Thermometer
1.2 This specification covers the thermocouple combina-
E988 Temperature-Electromotive Force (EMF) Tables for
tions of tungsten-3 % rhenium versus tungsten-25 % rhenium 3
Tungsten-Rhenium Thermocouples (Withdrawn 2011)
(W3Re/W25Re) and tungsten-5 % rhenium versus tungsten-
E1751 Guide for Temperature Electromotive Force (EMF)
26 % rhenium (W5Re/W26Re; Type C). All information ap-
Tables for Non-Letter Designated Thermocouple Combi-
plies to both combinations unless otherwise noted.
nations (Withdrawn 2009)
1.3 It is recognized that the alloys described are refractory
3. Terminology
and are not suitable for use at high temperatures in oxidizing
atmospheres. All tests and processes described herein must be
3.1 Definitions:
performed under conditions that are non-reactive to tungsten-
3.1.1 For definitions used in this standard, see Terminology
rhenium alloys.
E344.
3.2 Definitions of Terms Specific to This Standard:
1.4 The values stated in SI units are to be regarded as the
3.2.1 dope, vt—in this specification, to add potassium,
standard. The values given in parentheses are for information
silicon and aluminum compounds or other volatile substances
only.
tothealloypowdersduringthepreparationtoproduceaductile
1.5 This international standard was developed in accor-
wire. See NASA CR-72884.
dance with internationally recognized principles on standard-
3.2.1.1 Discussion—Some alloy powders are doped.
ization established in the Decision on Principles for the
3.2.2 lot, n—a quantity of wire processed or heat treated as
Development of International Standards, Guides and Recom-
a single continuous length and identified uniquely.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Ordering Information
2. Referenced Documents
4.1 Apurchase order for thermocouple material conforming
to this specification shall specify the following:
2.1 ASTM Standards:
4.1.1 Thermocouple Wire Composition—May be W3Re/
E8 Test Methods for Tension Testing of Metallic Materials
W25Re or W5Re/W26Re.
E207 Test Method forThermal EMFTest of SingleThermo-
4.1.2 Wire Size—Specify size with each order.
element Materials by Comparison with a Reference Ther-
4.1.3 Wire Length—Specify total amount of each wire and
minimum continuous length.
This specification is under the jurisdiction of ASTM Committee E20 on
4.1.4 Thermocouple Calibration—Calibration will be in
Temperature Measurement and is the direct responsibility of Subcommittee E20.13
accordance with Section 5.1.4 unless otherwise specified.
on Thermocouples - Materials and Accessories Specifications.
Current edition approved May 1, 2013. Published May 2013. Originally
approved in 1979. Last previous edition approved in 2007 as E696 – 07. DOI:
10.1520/E0696-07R13. The last approved version of this historical standard is referenced on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM NASA CR-72884, “Some Studies on Behavior of W-Re Thermocouple Mate-
Standards volume information, refer to the standard’s Document Summary page on rials at High Temperatures.” Available from National Aeronautics and Space
the ASTM website. Administration, 400 Maryland Ave. S.W., Washington, DC 20546.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E696−07 (2013)
4.1.5 Supplementary Requirements—SeetheSupplementary 5.1.4.3 The initial calibration tolerance shall be in accor-
Requirements section of this specification. dance with Table 1 (W3Re/W25Re). or Specification E230
4.1.6 Instructions for Spooling, Packaging, and Labeling— (W5Re/W26Re), as appropriate.
Packaging will be in accordance with Section 10 unless
5.2 Composition:
otherwise specified.
5.2.1 Positive thermoelement:
4.1.7 Tests and Certifications Required from the
5.2.1.1 The positive thermoelement for the W3Re/W25Re
Processor—Certification will be in accordance with Section 9
combination shall have a nominal composition of 97 % tung-
unless otherwise specified.
sten and 3 % rhenium.
5.2.1.2 The positive thermoelement for the W5Re/W26Re
5. Materials and Manufacture
combination shall have a nominal composition of 95 % tung-
5.1 Thermocouple Wire: sten and 5 % rhenium.
5.1.1 General—The thermoelements shall be tungsten-3 %
5.2.1.3 The positive thermoelement shall be doped to pro-
rhenium and tungsten-25 % rhenium or tungsten-5 % rhenium vide desirable grain structure and workability and maintain
and tungsten-26 % rhenium (Type C), as indicated on the
ductility after high temperature use.
purchase order.
5.2.2 Negative thermoelement:
5.1.2 Physical: 5.2.2.1 The negative thermoelement for the W3Re/W25Re
5.1.2.1 Thediameterofeachwireshallbewithin 60.01mm
combination shall have a nominal composition of 75 % tung-
(0.0005 in.) of the ordered size for 0.5 mm (0.02 in.) diameter sten and 25 % rhenium.
wire and smaller. The diameter of each wire shall be uniform
5.2.2.2 The negative thermoelement for the W5Re/W26Re
end-to-end to within 0.01 mm (0.0005 in.) for 0.5 mm (0.02 combination shall have a nominal composition of 74 % tung-
in.) diameter wire and smaller.
sten and 26 % rhenium.
5.1.2.2 The wires shall be solid, round, smooth and be free
6. Lot Identification
of weld joints, slivers, kinks, pits or nicks exceeding 5 % of
diameter.
6.1 Thermocouple wires, test results and certifications shall
5.1.2.3 Thewiresurfaceshallbeuniformlycleanandfreeof
be identified by manufacturer’s lot number.
discoloration.
5.1.2.4 Mechanical or optical methods may be used to
7. Lot Designation
verify the requirements of 5.1.2.1, 5.1.2.2, and 5.1.2.3.
7.1 A vendor who purchases wire from processors for
5.1.3 Mechanical:
repackaging and resale shall supply, for each spool, the wire
5.1.3.1 The wires shall withstand, at a temperature of 20 to
processor’s name, lot number and certification to the customer.
35 °C (68 to 95 °F), wrapping five turns around a mandrel five
times the diameter of the wire without breaking or splitting.
8. Extension Wires
5.1.3.2 The tests shall be m
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