The actual device attached to the specimen (e.g., clip-on, contact, or non-contact/video extensometers).
The standard is widely referenced by other test methods, such as ASTM E8 for tensile testing of metallic materials, making it a fundamental supporting document for many mechanical testing standards. astm e83 pdf
Many laboratories operating internationally need to understand the relationship between ASTM E83 and the international standard (Metallic materials — Calibration of extensometer systems used in uniaxial testing). While both standards address similar topics, there are important differences: The actual device attached to the specimen (e