A fiber optic, Fabry-Perot strain gauge calibrator

In this paper, we describe a compact, non-destructive calibration setup using a fiber optic Fabry-Perot interferometric (FOFPI) displacement sensor and a circular, mono-morphic piezoelectric plate actuator. The piezoelectric actuator strains the sensor under calibration, and the FOFPI measures the resulting displacement and strain. Using a linear fitting equation that relates the fractional change in sensor output and the measured strain, the strain gauge factor (SGF) is determined. For demonstration purposes, the setup is used to determine the strain gauge factor of a resistive strain gauge (RSG). The measured SGF of the RSG was found to be within 2% of the manufacturer's stated value.