Fibre optic pressure sensor has fibre-Bragg grids with approximately equal gas sensitivity; thermally induced Bragg wavelength displacements of at least 2 grids have predefined relationship

摘要

The sensor has an optical fibre (1) with at least two fibre-Bragg grids )10, 11) and a pressure transfer element (2) with a pressure body (3) and a reference body (4), to which the optical fibre is connected. The pressure transfer element converts the pressure of a medium into a longitudinal expansion or compression of at least one section of the optical fibre contg. a fibre-Bragg grid. The fibre-Bragg grids are arranged to have an approximately equal gas sensitivity and thermally induced displacements of the Bragg wavelength of at least two grids have a predefined mutual relationship.