About the fiber optic pressure sensors
In fiber optic pressure sensors, known as microbend sensors, the refractive index of the fiber and hence the intensity of light transmitted varies according to the mechanical deformation of the fibers caused by pressure. The sensitivity of pressure sensors can be optimized by applying the pressure via a roller chain such that the bending is applied periodically. The optimal pitch for the chain varies according to the radius, refractive index and type of cable involved. Microbend sensors are typically used to measure the small pressure changes generated in vortex-shedding flowmeters. Vortices can be detected more simply in the alternative version where a fiber optic cable is merely stretched across the pipe.