This paper focused on the experimental validation of diaphragm-based Fabry-Perot fiber optic pressure sensors (D-FP-FOPS) with ethylene propylene diene terpolymers (EPDM) diaphragm as designed and analyzed sensor tip theoretically. We also used self-adhesive EPDM rubber as a diaphragm for the first time in the literature. Analytical calculation and finite element method (FEM) analysis were carried out to obtain values of fundamental resonance frequency (f(0)) and deflection (d) with diaphragm specific values of Young's modulus and Poisson's ratio measured by tensile tests. We produced D-FP-FOPS tip with EPDM diaphragm and obtained experimental f(0) between 250-400 Hz from extended signal to noise ratio (SNR) plot which figured out with the help of theoretical values of f(0). We also analyzed minimum detectable pressure (MDP) mapping which is used to confirm SNR mapping for D-FP-FOPS. We noticed that our sensor could be operated up to 1.6 Pa pressure which confirms the mechanical limit given in the literature. Before production of D-FP-FOPS, a pioneering way which includes design, analytical calculation, FEM analysis, and experimental validation was demonstrated as a novel. Moreover, since we used self-adhesive EPDM tape as a diaphragm material, our sensor tip cost is less than 50 $ which capable to compete with commercial sensors.