Fiber-optic strain gauge manometer up to 100 MPa

A description is given of the realization of a pressure transducer, utilizing a fiber-optic strain sensor and an active element configured to simulate an infinite cylinder with free ends. The deformation of such a cylinder depends uniquely on the pressure acting from its inside and is independent of the stress resulting from the attachment of the device to the pressure system. The fiber-optic strain sensor is permanently bonded to the external surface of the cylinder and as such is fully isolated from the high pressure region. The sensing element of the device consists of a highly birefringent (HB) polarization-maintaining optical fiber strain gauge. The device was characterized for pressures up to 100 MPa. The sensor has inherent advantages such as immunity to electromagnetic interference, safety in electrically dangerous, hazardous or explosive environments, direct compatibility with optical data transmission systems, simplicity, and cost-effectiveness. It does not require any fiber-optic lead-through since it is located outside the pressure region and has significantly increased sensitivity (around 0.1 MPa/sup -1/) over similar devices based on electrical strain gauges.<<ETX>>