Development of a linear fiber optic pressure sensor

This paper deals with the theory, design, fabrication and test results of a fiber optic pressure sensor. It employs intensity modulation and diaphragm type elastic pressure sensor. The distance between diaphragm and optical fiber probe plays important role in achieving linearity and accuracy of measurement. It is designed in such a way that it can measure differential as well as gauge pressures. Prototype model was calibrated up to 6.6 kN/m² and has a sensitivity of 200 mV/kN/m². Range as well as sensitivity can be further increased with proper selection of diaphragm and its polish. Sources of error and their minimization have been discussed.