Fiber Optic Pressure Sensor of 0–0.36 psi by Multimode Interference Technique

Abstract

This paper presents the design, development and tests made to a fiber optic pressure sensor using the multimodalinterference methodology (MMI) thus, we propose an alternative sensor to the ones available which are limited byhigh robust environments where the use of them is a potential hazard (explosive gases, corrosion and evenelectromagnetic fields). The range of work for this sensor is 0 to 0.36 psi, the arrangement used is formed by a laserdiode, a sensing element, an electronic amplifying circuit, a data acquisition board and a computer. The sensingelement used is a SMS fiber optic structure (singlemode–multimode–singlemode, where a multimode fiber isembedded between two singlemode fibers) placed within the contact surface (diaphragm) made of a polymericmaterial; the body of the sensor was made of nylamid. The bending produced in the diaphragm by the pressure insidethe body of the sensor generates changes in the transmitted power response carried inside the fiber.