ASTM E83-25 PDF

Full title and description

ASTM E83-25 — Standard Practice for Calibration, Verification, and Classification of Extensometer Systems. This practice defines procedures and apparatus for verifying extensometer systems, classifying them by maximum error of indicated strain, and categorizing them by gage length. It is intended as a verification/classification practice rather than a complete purchase specification.

Abstract

This practice covers procedures for the calibration, verification, and classification of extensometer systems that indicate or record values proportional to changes in length for tensile or compressive strain. It specifies the verification apparatus (means for applying controlled displacements and accurately measuring those displacements), classification criteria based on maximum strain error (Classes A, B‑1, B‑2, C, D, and E), and gage‑length categories (Type 1, Type 2, Type 3). The practice notes exclusions (for example, directly bonded resistance strain gages are not verified with the same apparatus — see Test Methods E251) and permits use with either SI or US customary displacement units.

General information

• Status: Active standard (E83-25).
• Publication date: 2025 (document record shows publication/last update in 2025).
• Publisher: ASTM International.
• ICS / categories: 19.060 (Metallurgy; mechanical testing and related apparatus).
• Edition / version: E83-25 (current revision).
• Number of pages: 18 pages (document metadata indicates 18 pages).

Scope

The standard specifies methods for calibration, verification, and classification of extensometer systems that measure changes in length (strain) under tensile or compressive loads. It applies to extensometers that provide readings proportional to specimen length change and classifies systems by allowable error magnitude; it is not intended as a purchase specification and excludes bonded resistance strain gages from verification by the apparatus described (referencing Test Methods E251 for those devices). The practice supports both SI and US customary displacement units and includes provisions related to measurement uncertainty and verification apparatus requirements.

Key topics and requirements

• Definitions and terminology related to extensometer measurement and strain (references to Terminology E6 and related ASTM test methods).
• Requirements for verification apparatus: controlled displacement application to a simulated specimen and accurate measurement of applied displacement.
• Classification scheme by maximum error of indicated strain: Classes A, B‑1, B‑2, C, D, and E, with specified limits.
• Categorization by gage length into Type 1, Type 2, and Type 3 extensometer systems.
• Guidance on verification procedure and acceptance criteria, and references to related ASTM test methods (for example E251 for bonded resistance strain gages).

Typical use and users

Laboratories performing mechanical testing of materials, calibration laboratories, manufacturers of extensometers and test frames, quality assurance and metrology personnel, and standards committees rely on E83-25 for consistent verification and classification of extensometer performance. Users apply the practice when certifying extensometer accuracy for tensile/compressive testing, when establishing acceptance criteria for instrument purchases, and when documenting instrument performance for quality systems.

Related standards

Commonly referenced documents and related standards include: ASTM E6 (terminology for mechanical testing), ASTM E21 (elevated temperature tension tests), ASTM E251 (performance characteristics and calibration of bonded resistance strain gages), and international guides on measurement uncertainty (for example JCGM 100, the GUM). Historical and prior editions of E83 (for example E83‑23 and earlier) provide background on previous classification and verification language.

Keywords

extensometer, calibration, verification, classification, strain measurement, gage length, measurement uncertainty, extensometer types, test equipment, ASTM E83.

FAQ

Q: What is this standard?

A: ASTM E83-25 is a standard practice that provides procedures to calibrate, verify, and classify extensometer systems used to measure changes in length (strain) during tensile and compressive testing. It defines apparatus and acceptance criteria for verification.

Q: What does it cover?

A: It covers verification apparatus and procedures, classification by maximum error (Classes A, B‑1, B‑2, C, D, E), categorization by gage length (Type 1–3), and notes exclusions (e.g., bonded resistance strain gages are handled under Test Methods E251). It supports both SI and US customary units.

Q: Who typically uses it?

A: Calibration and mechanical testing laboratories, instrument manufacturers, quality and metrology engineers, and procurement/specification writers use E83-25 to verify extensometer performance and to set acceptance criteria.

Q: Is it current or superseded?

A: E83-25 is the current active revision (designation E83-25). It follows earlier revisions (for example E83‑23) and remains the active practice at the time of publication. Work items and revision ballots may be recorded against the document for future updates.

Q: Is it part of a series?

A: E83 is part of ASTM Committee E28’s suite of standards for calibration of mechanical testing machines and apparatus; it cross-references and complements other ASTM mechanical testing standards (E6, E21, E251, etc.).

Q: What are the key keywords?

A: Extensometer, calibration, verification, classification, strain, gage length, measurement uncertainty, tensile testing, compressive testing.