ASTM E696-00

Standard Specification for Tungsten-Rhenium Alloy Thermocouple Wire

SCOPE
1.1 This specification covers the requirements for bare, solid conductor, tungsten and rhenium alloy thermoelements having diameters of 0.13 mm (0.005 in.) to 0.5 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). 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 non-inert atmospheres. All tests and processes described herein must be performed under suitably inert conditions that are nonreactive 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

• Status: Historical
• Publication Date: 09-Oct-2000
• ICS: 17.200.20 - Temperature-measuring instruments
• Technical Committee: E20 - Temperature Measurement

Relations

• Replaced By: ASTM E696-07 - Standard Specification for Tungsten-Rhenium Alloy Thermocouple Wire
• Effective Date: 01-May-2007
• Referred By: ASTM E344-20 - Terminology Relating to Thermometry and Hydrometry
• Effective Date: 10-Oct-2000
• Referred By: ASTM E1751/E1751M-20 - Standard Guide for Temperature Electromotive Force (emf) Tables for Non-Letter Designated Thermocouple Combinations
• Effective Date: 10-Oct-2000

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E 696 – 00
Standard Specification for
Tungsten-Rhenium Alloy Thermocouple Wire
This standard is issued under the fixed designation E 696; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope E 988 Temperature-Electromotive Force (EMF) Tables for
Tungsten-Rhenium Thermocouples
1.1 This specification covers the requirements for bare,
solid conductor, tungsten and rhenium alloy thermoelements
3. Terminology
having diameters of 0.13 mm (0.005 in.) to 0.5 mm (0.020 in.)
3.1 Definitions:
supplied in matched pairs. These thermoelements shall be
3.1.1 For definitions used in this standard, see Terminology
suitable for use either in bead-insulated, bare-wire thermo-
E 344.
couples, or in compacted metal-sheathed, ceramic insulated
3.2 Definitions of Terms Specific to This Standard:
thermocouple material or assemblies.
3.2.1 dope, vt—in this specification, to add potassium,
1.2 This specification covers the thermocouple combina-
silicon and aluminum compounds to the alloy powders during
tions of tungsten-3 % rhenium versus tungsten-25 % rhenium
the preparation to produce a ductile wire. See NASA CR-
(W3RE/W25RE) and tungsten-5 % rhenium versus tungsten-
72884.
26 % rhenium (W5RE/W26RE). All information applies to
3.2.2 Discussion—Alloy powders are doped.
both combinations unless otherwise noted.
1.3 It is recognized that the alloys described are refractory
4. Ordering Information
and are not suitable for use at high temperatures in non-inert
4.1 Apurchase order for thermocouple material conforming
atmospheres. All tests and processes described herein must be
to this specification should specify the following:
performed under suitably inert conditions that are non-reactive
4.1.1 Thermocouple Wire Composition— May be doped
to tungsten-rhenium alloys.
W3RE/W25RE or doped W5RE/W26RE.
1.4 The values stated in SI units are to be regarded as the
4.1.2 Wire Size—Specify size with each order.
standard. The values given in parentheses are for information
4.1.3 Wire Length—Specify total amount of each wire and
only.
minimum continuous length.
4.1.4 Thermocouple Calibration—Paired wires shall be fur-
2. Referenced Documents
nished to the initial calibration tolerances stated in 5.1.4.2
2.1 ASTM Standards:
2 unless otherwise requested.
E 8 Test Methods forTensionTesting of Metallic Materials
4.1.5 Required Mechanical Properties— See 5.1.3.
E 207 Test Method for Thermal EMF Test of Single Ther-
4.1.6 Instructions for Spooling, Packaging, and Labeling—
moelement Materials by Comparison with a Reference
3 Wires shall be supplied on spools of a nominal 100 mm (4-in.)
Thermoelement of Similar EMF-Temperature Properties
diameter core and boxed individually, unless otherwise re-
E 220 Test Method for Calibration of Thermocouples by
3 quested. Each spool shall be marked to identify the wire
Comparison Techniques
composition, diameter, quantity, processor’s name, spool des-
E 344 Terminology Relating to Thermometry and Hydrom-
3 ignation and customers purchase order number in a manner to
etry
identify the pair of wires to be used to form a thermocouple
E 452 Test Method for Calibration of Refractory Metal
meeting the calibration requirement.
Thermocouples Using an Optical Pyrometer
4.1.7 Tests and Certifications Required from the
Processor—Unless otherwise requested, the processor shall
1 supply a certificate with each order stating the wire composi-
This specification is under the jurisdiction of ASTM Committee E20 on
Temperature Measurement and is the direct responsibility of Subcommittee E20.04 tion, size and calibration information.
on Thermocouples.
Current edition approved Oct. 10, 2000. Published December 2000. Originally
published as E 696–79. Last previous edition E 696–95. NASA CR-72884, “Some Studies on Behavior of W-Re Thermocouple Mate-
Annual Book of ASTM Standards, Vol 03.01. rials at High Temperatures.” Available from National Aeronautics and Space
Annual Book of ASTM Standards, Vol 14.03. 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.
E 696
5. Materials and Manufacture of the reference length and test pieces of known, practical
lengths should be within 0.005 mm (0.0002 in.) of each other.
5.1 Thermocouple Wire:
5.1.5.3 The resistance measurement taken according to
5.1.1 General—The thermoelements shall be tungsten-3 %
5.1.5.2 shall be compared to the dc resistance measurements of
rhenium and tungsten-25 % rhenium or tungsten-5 % rhenium
each measured full length of wire.
andtungsten-26 %rhenium,asindicatedonthepurchaseorder.
5.1.5.4 The full length resistance per unit length (ohms per
5.1.2 Physical:
meter or foot) of each of the test lengths shall be within 10 %
5.1.2.1 The diameter of each wire shall be uniform end-to-
of the value obtained from the reference length.
end to within 0.01 mm (0.0005 in.) for 0.5 mm (0.02 in.)
NOTE 1—The resistivity of W25RE and that of W26RE is more than
diameter wire and smaller.
double that of either W3RE or W5RE, and all of these alloys have high
5.1.2.2 The wires shall be solid, round, smooth and be free
temperature coefficients of resistance.
of weld joints, slivers, kinks, pits or nicks exceeding 5 %
...