Fiber-optic strain-gauge manometer up to 100 MPa

A practical realization of a novel pressure transducer utilizing a fiber-optic strain sensor and an active element configured to simulate an infinite cylinder with free ends is described. The deformation of such a cylinder depends uniquely on 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 bound 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 at ambient temperatures for pressure up to 100 MPa. The sensor has inherent advantages such as immunity to electromagnetic interference, safety, direct compatibility with optical data transmission systems, simplicity and cost-effectiveness. It does not require any fiber-optic leadthrough and has significantly increased sensitivity (around 0.1 MPa/sup -1/) compared to similar devices based on electrical strain gauges.<
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