©2010 International Journal of Computer Applications (0975 – 8887) Volume 1 – No. 14 73 Modeling Simulation and Fabrication of Fiber Optic Pressure Sensor Pobe M.L.Dongare Department of Electronic Science S.M.Joshi College, Hadapsar, Pune - 4110 28, India P.B.Buchade Department of Electronic Science Abasaheb Garware College Pune - 411004, India A.D.Shaligram Department of Electronic Science, University of Pune, Pune – 411007, India ABSTRACT Elastic element mechanical pressure gages consisting diaphragm are basically used for the differential pressure measurement. In FODPS, diaphragm acts as a reflector. A flexible disc of plastic is used as a diaphragm to convert the measuring pressure to the deflection of diaphragm. Concentric corrugations are designed to linearise the deflections according to pressure. Reference and measuring pressures are applied to control and experimental headspaces respectively. As the pressure changes in the experimental head space, the diaphragm is deform and displaces, and distance between fiber tip and plane of diaphragm changes and thus resultant reading is proportional to the differential pressure. Keywords Diaphragm, FODPS, pressure, sensor 1. INTRODUCTION The FODPS is needed in physical, chemical, biochemical, analytical and biomedical applications [1-3]. The diaphragm deformation due to change in pressure was sensed by FODPS. The change in output due change in pressure was measured in terms of voltage. The application of fiber optic sensors in pressure measurement has the advantage that there is no physical contact with the process parameter to be measured. Block diagram of FODPS is shown in figure.1. A flexible plastic disc is used as a diaphragm to convert the measuring pressure to the deflection of diaphragm. The FODPS is based on intensity modulation technique. Plastic fibers are used for its construction. The design aspect includes details of assembly of pressure chamber and sensing zone. The diaphragm deformation due to change in pressure was sensed by FODPS. The change in output voltage of the FODPS due to change in air pressure is acquired through ADC and directly displayed on LCD connected to a microcontroller. Figure1. Block diagram of FODPS 2 Modeling and Simulation of FODPS Simulation is carried for varying a pressure at experimental side. The reference pressure was kept constant throughout the work. Initial pressure applied on both sides of the diaphragm was 21325 Pa. Simulation values for pressure drop, on experimental sides varied from upper limit 21325 pa to lower limit rang 0 pa., because 21325 Pa is the partial pressure of pure distilled water. The geometrical information and corresponding changes through developed sensor are translated in to 3-D model. Diaphragm of plastic material of thickness 0.2mm, diameter 70 mm and applied pressure is from 1kpa to 21kpa. For a small deflection range, the diaphragm deflections are mainly due to bending stresses in the plate. The deflection and the stresses developed due to uniformly acting pressure on diaphragm can be determined from the theory of plates. We have used ANSYS as a FEA tool. It is a critical part in the whole structure of FODPS model of corrugated diaphragm. Estimation of its deflection was calculated using ANSYS. Finite element method is used for simulation of diaphragm under static pressure [4]. The overall equilibrium equation for linear structural static analysis [5] is given by Microcontroller Diaphragm Sensing Head Reference Pressure Modulation Zone SCU LED Photo Detector D Fiber