Abstract: An interferometric sensing arrangement includes an interferometric sensor having an optical path length that varies depending on one or more physical parameters to be measured using the interferometric sensor. One or more light sources are used to generate light at three or more predetermined different fixed wavelengths. In a preferred example embodiment, four fixed wavelength lasers are used to generate light at four predetermined different fixed wavelengths. An optical coupler couples the multiple wavelength light to the interferometric sensor, and a detector measures an amplitude response of an interferometric signal produced by the interferometric sensor. A controller determines the optical path length based on the measured amplitude response.

Abstract: A fiber optic system (10, 210) including a plurality of optical sensors, each with an identification system (20, 120, 220, 320). The fiber optic system (10) includes a fiber (12, 112) extending a distance, a demodulator (14), and at least one coupler (16, 116), optical sensor (18, 118) and corresponding identification system (20, 120). The identification system (20, 120) is powered by light shunted from the fiber (12, 112) by the coupler (16, 116) to a modulating device (24, 124). The modulating device (24, 124) modulates the light and transmits it to a power converting device (16, 116), which transforms the light energy into electrical energy. The electrical energy powers a high temperature integrated circuit (28, 128) upon which is stored a digital identification of a respective optical sensor (18, 118). The integrated circuit (28, 128), upon being powered up, sends a modulated response (30, 130) back up to the surface through the modulating device (24, 124).

Abstract: An optical sensor (10) that provides for concurrent pressure and temperature measurements at substantially the same location includes at least one launch fiber (22) and at least one temperature sensitive material (52) having a refractive index that changes with a change in temperature. The launch fiber and temperature sensitive material are spaced from each other across a gap (21) having length (L). A reflecting fiber (26) can be provided adjacent the temperature sensitive material. The optical sensor (10) also includes a sealed cavity (20). The launch fiber (22) and reflecting fiber (26) can be attached to the tube and at least partially disposed within the cavity. Changes in pressure change the length (L) of the gap (21).

Abstract: An optical inclination sensor is provided having at least one reflective surface and at least two separate optical fibers having ends spaced from a reflective surface. As the reflective surface tilts with respect to a pre-determined reference position the gap lengths between the fiber ends and the reflective surface change and the differences in these gap lengths is used to calculate an angle of inclination with respect to a reference position. The optical inclination sensor can include at least one mass attached to a housing and moveable with respect to the housing as the mass and housing are rotated about one or more axes. Optical strain sensors are disposed a various locations between the mass and housing so that as the mass moves with respect to the housing, each one of the optical strain sensors are placed in compression or tension. The housing can be a generally u-shaped housing having two arms and a base section with the mass disposed within the housing.

Abstract: A sensor assembly includes a stainless steel tubular housing. Within the housing is a polyetheretherketone tube and a sensor. An optical fiber joins the sensor to a transmission cable and is fixedly positioned within the tube. A first end of the housing includes a pressure transmission device or bellows and the second end of the housing is crimped about the tube to fixedly position the tube and the sensor within the housing. The sensor assembly is positioned within a channel of a gasket to obtain pressure data from a combustion chamber. This abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An optical sensor that includes multiple filter cavities for the simultaneous, co-located measurement of pressure and a temperature in a single structure. The sensor may include a single launch fiber bonded to a tube a pre-determined distance from a reflective fiber. The end of the reflective fiber not encased within the tube is enclosed within a cap formed of a material that has a refractive index that changes with changing temperature. Alternatively, a material having a refractive index that changes with changing temperature can be inserted into the tube to take the place of the reflective fiber. Multiple launch fibers may be incorporated within a tube.

Abstract: A sensor assembly includes a stainless steel tubular housing. Within the housing is a polyetheretherketone tube and a sensor. An optical fiber joins the sensor to a transmission cable and is fixedly positioned within the tube. A first end of the housing includes a pressure transmission device or bellows and the second end of the housing is crimped about the tube to fixedly position the tube and the sensor within the housing. The sensor assembly is positioned within a channel of a gasket to obtain pressure data from a combustion chamber. This abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.