ASTM B77-07 (2018) PDF

Full title and description

ASTM B77-07(2018) — Standard Test Method for Thermoelectric Power of Electrical-Resistance Alloys. This method specifies procedures for measuring the thermoelectric power (Seebeck coefficient) of resistance alloys with respect to copper, intended to assess suitability of materials used in resistance heating, precision resistors and related electrical-resistance applications.

Abstract

A concise two‑page test method that defines apparatus, sample preparation, temperature control and measurement procedures to determine thermoelectric power of metals and alloys relative to copper when the junction temperatures lie between 0 °C and 100 °C. The method emphasizes reproducible measurement practices for quality control and material selection where low thermoelectric power is required.

General information

• Status: Active (reapproved/revised designation B77-07R18 / B77-07(2018)).
• Publication date: Original adoption 2007 (designation B77‑07); reapproval / last update recorded November 15, 2018 (B77‑07R18 / B77‑07(2018)).
• Publisher: ASTM International (Committee B02, Subcommittee B02.10).
• ICS / categories: 77.120.01 — Non‑ferrous metals in general.
• Edition / version: B77‑07R18 (often cited as B77‑07(2018)).
• Number of pages: 2 pages (concise test method).

Scope

This test method covers determination of the thermoelectric power (EMF per degree) of a metal or alloy with respect to copper for junction temperature ranges between 0 °C and 100 °C. It defines recommended temperature differences, measurement arrangements (for example, separate oil baths or thermostatted baths for junctions), and general recommendations for measurement accuracy and reporting. The method is intended for materials used in resistance apparatus where low thermoelectric power relative to copper is important.

Key topics and requirements

• Definition of thermoelectric power and relation to Seebeck effect for metal-to-copper comparisons.
• Specified junction temperature range: 0 °C to 100 °C and guidance on mean temperature selection.
• Requirement that the temperature difference between junctions not be less than recommended minimums for reproducible results (practical guidance often recommends differences on the order of tens of degrees as appropriate for the material and apparatus).
• Apparatus and measurement practice: thermostatted baths or equivalent means to control junction temperatures, accurate temperature measurement, and low-noise emf measurement techniques.
• Units and reporting: inch‑pound units are customary in the standard text; SI conversions are provided for information.
• Scope of use: material selection, quality control and comparative testing of resistance alloys used in heating elements and precision resistors.

Typical use and users

Used by materials engineers, quality and test laboratories, manufacturers of resistance heating wire and precision resistors, R&D teams evaluating alloy performance, and standards/testing organizations. Typical applications include selection and acceptance testing of resistance alloys where low thermoelectric offsets relative to copper are required and comparative characterization of new alloy formulations.

Related standards

Related ASTM and industry documents commonly referenced in conjunction with B77 include other test methods and specifications for resistance alloys and heating elements (for example, ASTM standards covering heating‑element alloys, accelerated life tests for heating alloys, and specification/test methods for precision resistor materials). Users should consult the normative references listed in the B77 text for the exact related documents to be applied for a given testing program.

Keywords

thermoelectric power, Seebeck coefficient, electrical‑resistance alloys, resistance wire, copper reference, junction temperature, thermostatted baths, precision resistors, material selection, test method.

FAQ

Q: What is this standard?

A: ASTM B77-07(2018) is a short, prescriptive test method for measuring the thermoelectric power (relative EMF) of electrical‑resistance alloys with respect to copper, used to evaluate materials for resistance heating and precision resistor applications.

Q: What does it cover?

A: It covers measurement procedures, recommended temperature ranges (0 to 100 °C), apparatus guidance (temperature control and EMF measurement) and reporting conventions for thermoelectric power determinations.

Q: Who typically uses it?

A: Materials and test laboratories, resistance‑wire and heating‑element manufacturers, designers of precision resistors and instrument makers, and R&D groups assessing alloy behavior.

Q: Is it current or superseded?

A: The method B77‑07 is maintained in reapproved/revised form as B77‑07R18 (often cited as B77‑07(2018)). Users should verify through ASTM International for any newer revisions or withdrawals before relying on the method for regulatory or contract purposes.

Q: Is it part of a series?

A: It belongs to ASTM Committee B02 (Nonferrous Metals and Alloys) and is related to other ASTM test methods and specifications for resistance alloys and heating elements; consult the committee listings or the B02 subcommittee for the broader series of related standards.

Q: What are the key keywords?

A: Thermoelectric power, Seebeck coefficient, electrical‑resistance alloys, copper reference, junction temperature, precision resistors, resistance wire.