In a compression test, there is a linear region where the material follows Hooke's Law.
This linear region terminates at what is known as the yield point.
This linear region is called "polarization resistance" due to its formal similarity to the Ohm's law.
Every electrode has a range of scan rates called the linear region.
To use this range, a negative bias voltage had to be applied to the grid to position the DC operating point in the linear region.
Stress and strain control analyzers give about the same results as long as characterization is within the linear region of the polymer in question.
If using a micro-plate reader, the test is quantitative and dose-response curves have an initial linear region.
The modulus is the slope of the initial linear region of the stress-strain curve.
The linear region falls between 1.
Beyond this linear region, for ductile materials, such as steel, deformations are plastic.