ASTM E696-23 PDF
Name in English:
St ASTM E696-23
Name in Russian:
Ст ASTM E696-23
Original standard ASTM E696-23 in PDF full version. Additional info + preview on request
Full title and description
ASTM E696-23 — Standard Specification for Tungsten‑Rhenium Alloy Thermocouple Wire. This specification defines requirements for bare, solid tungsten‑rhenium thermoelement conductors supplied in matched pairs for use in high‑temperature thermocouples (including W3Re/W25Re and W5Re/W26Re combinations).
Abstract
This specification covers bare solid conductors made from tungsten‑rhenium alloys (commonly W‑3%Re vs W‑25%Re and W‑5%Re vs W‑26%Re — Type C). It specifies acceptable diameters, compositional and physical requirements, tolerances, and intended assembly types (bead‑insulated, bare‑wire, compacted metal‑sheathed, ceramic‑insulated assemblies). The standard notes these alloys are refractory and must be handled/tested in non‑oxidizing environments.
General information
- Status: Active / Published.
- Publication date: 2023 (effective/issue date June/July 2023).
- Publisher: ASTM International (formerly American Society for Testing and Materials).
- ICS / categories: 17.200.20 — Temperature‑measuring instruments (classification used for this standard).
- Edition / version: E696‑23 (2023 revision).
- Number of pages: 4 pages (concise specification).
Scope
Applies to bare, solid tungsten‑rhenium thermoelement wires with nominal diameters from 0.127 mm (0.005 in.) to 0.508 mm (0.020 in.) supplied in matched pairs for construction of refractory‑metal thermocouples. Covers the two common refractory thermocouple combinations (W3Re/W25Re and W5Re/W26Re), required physical and mechanical properties, compositional limits, and intended assembly types. The standard clarifies that these alloys are unsuitable for oxidizing atmospheres at high temperature and that handling and testing must avoid reactions with the alloys.
Key topics and requirements
- Designation of acceptable alloy combinations: W‑3%Re vs W‑25%Re and W‑5%Re vs W‑26%Re (Type C thermocouple combinations).
- Approved nominal wire diameters (0.127 mm to 0.508 mm) and tolerances for diameter uniformity and straightness.
- Requirements for matched‑pair supply and resistance/continuity checks to ensure thermoelectric pairing.
- Physical and mechanical property limits (surface quality, freedom from kinks/nicks/welds, dimensional tolerances).
- Compositional limits and metallurgical quality for reliable thermoelectric performance.
- Guidance that fabrication, testing and use must be in non‑oxidizing or inert/reducing environments due to alloy reactivity at high temperature.
- Requirements for labeling, packaging and identification of alloys and sizes for traceability and correct pairing.
Typical use and users
Used by thermocouple manufacturers, high‑temperature instrumentation suppliers, aerospace and turbine test laboratories, research institutions and industrial users requiring refractory‑metal thermocouples for measurements in inert or reducing environments (e.g., vacuum furnaces, inert gas environments, metallurgical processing). Engineers and procurement professionals reference this specification when sourcing tungsten‑rhenium thermoelement wire to ensure interchangeability and traceable material properties.
Related standards
Related and commonly referenced standards include ASTM E988 (temperature‑EMF tables for tungsten‑rhenium thermocouples), ASTM E452 (calibration/test methods for refractory metal thermocouples), and other E20 committee documents covering thermocouple materials and accessories. Users should consult companion ASTM standards for EMF tables, calibration tolerances and mounting/assembly methods.
Keywords
tungsten‑rhenium, thermocouple wire, thermoelement, W3Re, W25Re, W5Re, W26Re, Type C thermocouple, refractory metals, high‑temperature measurement, matched pairs.
FAQ
Q: What is this standard?
A: ASTM E696‑23 is the ASTM International specification that defines the material, dimensional, mechanical and pairing requirements for tungsten‑rhenium alloy thermocouple wire (refractory thermoelements).
Q: What does it cover?
A: It covers bare, solid tungsten‑rhenium thermoelement conductors (typical diameters 0.127–0.508 mm), acceptable alloy combinations (W3Re/W25Re and W5Re/W26Re), required physical and compositional properties, pairing and supply practices, and cautions about use in oxidizing atmospheres.
Q: Who typically uses it?
A: Thermocouple and sensor manufacturers, calibration and test laboratories, aerospace and industrial engineers, procurement/specification writers, and research groups working with high‑temperature measurements in inert or reducing environments.
Q: Is it current or superseded?
A: E696‑23 is the 2023 revision and is published/active as of 2023 (check formal publisher records for any later revisions).
Q: Is it part of a series?
A: It is part of the ASTM E20 (Temperature Measurement) committee output and is commonly used alongside related standards such as ASTM E988 (EMF tables for tungsten‑rhenium thermocouples) and calibration/test method standards for refractory thermocouples.
Q: What are the key keywords?
A: tungsten‑rhenium, thermocouple, thermoelement, W3Re, W25Re, W5Re, W26Re, Type C, refractory, high‑temperature measurement.