How can you measure "strain"?

Measurement method for measuring strain

The straincan be measured directly

• With strain gauges ("electrical"),
• With strain gauges ("optical"),
• With stress-optical methods,
• With zipper,
• with magnetoelastic materials,
• with piezoelectric materials.

The strain can be measured indirectly

• with distance sensors and relation of "length change" to the "reference length"
• ...