Astm E83 Pdf ((link)) -

The extensometer is mounted onto the calibration rig in a manner identical to how it would be used on a specimen. Care must be taken to avoid applying torque or stress that could skew the reading.

: Check for mechanical wear, damaged knife edges, or electrical issues. astm e83 pdf

To ensure compliance with ASTM E83, laboratories and testing facilities should: The extensometer is mounted onto the calibration rig