An Optical Fibre Sensor For The Measurement Of Pressure

Abstract

The paper describes the design, construction and testing of a fibre optic pressure sensor based on a reflecting Fabry -Perot etalon.The etalon comprised one fixed mirror and a second mirror designed to flex under the action of the pressure being monitored.A single multimode fibre was used to connect the passive, remote sensor to the transmitter /receiver section, and dual wavelength referencing was used to eliminate the effects of bending-induced attenuation in the fibre.

MEMS versus MOMS from a systems point of view

“…Other possible techniques include diffraction gratings, fluorescence and interferometry, e.g. by way of a Fabry-Perot cavity [10], though strictly speaking the latter is a phase sensing method. Diffraction gratings and Fabry-Perot cavities lend themselves well to silicon fabrication technologies.…”

Optical fibre pressure measurement

“…This may best be visualized by referring back to figure 4, and noting that there is a radial contribution to the overall strain monitored from 0 to 71 radians. The determination of each component may be described geometrically [SI, and the integrated strain (EJ for each 4 may be written as E= = J : E cos' 'p d'p (3) where E is the radial strain at the centre of the diaphragm in one direction only. This integrated strain for the centre of the diaphragm was calculated as -580pm m-' for the intended maximum pressure.…”