Principle and Error Analysis of Two-side Electronic Extensometer

The measurement instability and errors of one-side electronic extensometer were discussed and the measurement principle of two-side electronic extensometer was introduced. The relationship between diagonal elongation and axial elongation of tensile specimen in a two-side electronic extensometer was established. It proved that the measurement results of a two-side electronic extensometer are not impacted by eccentric tension and the system error of it is very small or even zero.