Related Experiment Video
Updated: Jun 17, 2026

Measuring Local Tissue Strains in Tendons via Open-Source Digital Image Correlation
Published on: January 27, 2023
Abstract:
An optical strain gauge has been built to measure extremely small torsion strains in cylindrical specimens. Moiré fringe techniques are used to measure the differential angular changes between two sensing mirrors supported on two rings attached to the specimen. The present instrument has a useable linear range of about 0.5 mrad with a sensitivity of 500 mV/mrad. Angular changes as small as 2 microrad are easily detected. Risley prisms are used to extend the range to 10 mrad as well as to verify the calibration procedure.
Related Concept Videos
Measurements of Strain
Design Example: Strain Gauge Bridge or Wheatstone Bridge
Stress-Strain Diagram
Angle of Twist - Elastic Range
Torsion of Noncircular Members
Thin-Walled Hollow Shafts

