ASTM E977-05 (2023) PDF

Full title and description

ASTM E977 − 05 (Reapproved 2023) — Standard Practice for Thermoelectric Sorting of Electrically Conductive Materials. This practice describes procedures for sorting electrically conductive materials using the thermoelectric (Seebeck) effect and covers both direct- and comparator-type thermoelectric instruments used to distinguish variations in material composition and metallurgical state.

Abstract

This practice specifies how to perform thermoelectric sorting by producing and measuring thermoelectric voltages generated when test pieces contact electrodes at different temperatures. It explains direct instrumentation (absolute voltage measurement against standards) and comparator instrumentation (relative comparison to known standards), required temperature differentials, standardization procedures, and considerations such as surface contamination and contact quality that affect measurement reliability.

General information

• Status: Active — reapproved 2023 (current practice).
• Publication date: December 1, 2023 (current edition approved Dec 1, 2023).
• Publisher: ASTM International.
• ICS / categories: 29.050 (Superconductivity and conducting materials) — categorized under specialized nondestructive testing methods.
• Edition / version: E977 − 05 (Reapproved 2023).
• Number of pages: 3 (brief practice document).

Scope

This practice covers the procedure for sorting electrically conductive materials by the thermoelectric method (Seebeck effect). It applies to the use of direct and comparator thermoelectric instruments to distinguish material variations that affect thermoelectric properties, and describes instrument standardization, acceptable ranges, and test-piece handling. It also notes limitations and factors (for example, rust, oil, scale, or poor contact) that can insulate or alter readings and therefore must be controlled or removed prior to testing.

Key topics and requirements

• Thermoelectric principle (Seebeck effect) as the basis for sorting.
• Direct-instrumentation technique: absolute voltage measurement and standardization against known reference materials.
• Comparator-instrumentation technique: relative comparison to one or more known standards with defined acceptance limits.
• Instrument requirements: capability to maintain a sufficient temperature differential across electrodes and stable measurement of thermoelectric voltage.
• Standardization and calibration procedures to set instrument response range and acceptance limits.
• Specimen preparation and surface condition requirements (removal/avoidance of rust, grease, mill scale, and other insulating contaminants).
• Electrode contact quality and consistent test-fixture practice to ensure reproducible results.
• Data interpretation rules: recognizing acceptable deviations, repeatability, and limits of resolution for sorting decisions.

Typical use and users

Common users include nondestructive testing laboratories, metallurgical and materials inspection groups, scrap and recycling facilities, incoming goods inspection in metal-processing plants, and quality-control personnel who need a rapid, nondestructive method to separate or screen electrically conductive parts by composition or metallurgical condition. The practice is maintained under ASTM Committee E07 on Nondestructive Testing, Subcommittee E07.10 on Specialized NDT Methods.

Related standards

Related ASTM and NDT documents include other nondestructive identification and sorting guides and practices referenced by ASTM Committee E07 (for example, guides and practices for electromagnetic, spectrochemical, and other sorting/identification methods). Documents that cite or reference E977 appear in collections of NDT guidance and related committee publications for material identification and sorting.

Keywords

thermoelectric sorting, Seebeck effect, direct instrumentation, comparator instrumentation, thermoelectric voltage, material sorting, nondestructive testing, electrode contact, calibration, ASTM E977.

FAQ

Q: What is this standard?

A: It is ASTM E977 − 05 (Reapproved 2023), a short practice that defines procedures for thermoelectric sorting of electrically conductive materials using the Seebeck effect.

Q: What does it cover?

A: It covers the operating principles and practical procedures for direct and comparator thermoelectric instruments, instrument standardization and calibration, specimen handling, and factors that affect measurement quality (such as surface contamination and contact quality).

Q: Who typically uses it?

A: Nondestructive testing engineers, metallurgical inspectors, recyclers and scrap sorters, incoming inspection teams, and quality-control laboratories that need a rapid nondestructive screening method for conductive materials.

Q: Is it current or superseded?

A: Current — the practice E977 − 05 was reapproved in 2023 and remains an active ASTM practice (current edition approved December 1, 2023).

Q: Is it part of a series?

A: It is part of the body of ASTM Committee E07 nondestructive testing practices and sits alongside other material-identification and sorting guides under Subcommittee E07.10; it is a standalone practice focused specifically on thermoelectric sorting.

Q: What are the key keywords?

A: Thermoelectric, Seebeck effect, comparator, direct measurement, electrode, material sorting, NDT, calibration, ASTM E977.