The difference between the displacement indicated by the extensometer and the actual displacement produced by a certified calibration apparatus.

At least two series of readings (runs) are taken to check for repeatability and hysteresis.

This guide breaks down the core sections of the ASTM E83 standard document, the technical nuances of classification tiers, and the practical implementation steps required during lab calibrations. 1. Scope and Core Purpose of ASTM E83

ASTM E83 classifies extensometer systems into four classes:

Allows test results from different laboratories worldwide to be compared accurately. Key Classifications Under ASTM E83

The core value of the ASTM E83 document is its classification table. Extensometers are not universally "accurate" or "inaccurate." Instead, they are graded into specific classes based on their performance across two primary metrics: and Fixed Error . The standard classifies systems into the following tiers:

: Commonly used for materials with higher elongation properties, such as plastics, composites, and certain wire products.

Keep standard operating procedures (SOPs) updated with the latest revisions of the standard. Key Components of the ASTM E83 Standard

Regular calibration documented via ASTM E83 guidelines provides a clear paper trail for ISO 9001 and Nadcap audits. The Classification System of ASTM E83

: Guidelines on how to document the verification results and classification. Where to Access Astm E83-16 | PDF - Scribd

The standard applies to any instrument that indicates or records values proportional to changes in length caused by either tensile or compressive strain. It is relevant across numerous industries, including aerospace, automotive, construction, metallurgy, and plastics manufacturing, wherever precise material property testing is required.

This comprehensive guide breaks down what ASTM E83 covers, why it matters, how calibration works, and how to interpret its classification system. What is ASTM E83?