Optical sensor and method for measuring the pressure of a fluid

摘要

Optical sensor (1) for measuring the pressure of a fluid comprises a transducer (3) with a deformable membrane to which membrane two fibre Bragg gratings (FBG) are attached, one at each side of the membrane. The sensor further comprises a tuneable small band light source (2) for providing light with a small band wavelength varying in time to the fibre Bragg gratings, a photodetector (5) for detecting light diffracted from the fibre Bragg gratings, and a timer (7) for determining at which points in time the diffracted light is detected. This optical sensor does not require a reference light source and neither a temperature sensor. The sensor can be used to measure the level of a liquid. Method for measuring the pressure of a fluid, comprises the step of providing light with a small band wavelength varying in time to two fibre Bragg gratings attached to the opposite sides of a membrane. The method further comprises the step of detecting the light diffracted by the fibre Bragg gratings and the step of determining at which points in time the diffracted light is detected. The method can be used to measure the level of a liquid.