Abstract: Methods of detecting non-uniformities in a material are described. Such methods can comprise inducing changes in strain state or changing the magnetic moment of a material and measuring magnetic flux leakage that is synchronous with the changes in strain state or magnetic moment, while simultaneously applying an external magnetic field to control the relative magnitude of the magnetic flux leakage.

Abstract: Methods of detecting non-uniformities in a material are described. Such methods can comprise inducing changes in strain state or changing the magnetic moment of a material and measuring magnetic flux leakage that is synchronous with the changes in strain state or magnetic moment, while simultaneously applying an external magnetic field to control the relative magnitude of the magnetic flux leakage.

Abstract: An optical fiber-based sensor assembly in the form of a cable assembly that can measure at least both pressure characteristics and temperature characteristics of a pressurized fluid in a channel in which the sensor cable assembly is disposed.

Abstract: Disclosed herein is a carrier for an optical fiber having a plurality of optical sensors located thereon. The carrier has a test section comprising a cavity and at least one geometric discontinuity, wherein in response to a pressure applied to the test section, a stress concentration is formed proximate to the geometric discontinuity, and wherein the optical sensor is adhered to at least a part of the geometric discontinuity. The cavity may be filled with a liquid or a gel. A temperature optical sensor may also be provided adjacent to the pressure optical sensor.

Abstract: Disclosed herein is a carrier for an optical fiber having a plurality of optical sensors located thereon. Such carrier can be a thick-walled capillary tube or other shapes. The carrier has a sealed hollow body with a side wall. The side wall is profiled at least one predetermined location to form a thin-walled section and at least one optical sensor is attached to said thin-walled section. As the thin-walled section flexes in response to a pressure difference across it, the pressure difference is sensed by the optical sensor. The carrier may also have a slot defined on its side wall to receive the optical fiber. A temperature optical sensor may also be provided adjacent to the pressure optical sensor.

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: 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: 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: Disclosed herein is a carrier for an optical fiber having a plurality of optical sensors located thereon. The carrier has a test section comprising a cavity and at least one geometric discontinuity, wherein in response to a pressure applied to the test section, a stress concentration is formed proximate to the geometric discontinuity, and wherein the optical sensor is adhered to at least a part of the geometric discontinuity. The cavity may be filled with a liquid or a gel. A temperature optical sensor may also be provided adjacent to the pressure optical sensor.

Abstract: Disclosed herein is a carrier for an optical fiber having a plurality of optical sensors located thereon. Such carrier can be a thick-walled capillary tube or other shapes. The carrier has a sealed hollow body with a side wall. The side wall is profiled at least one predetermined location to form a thin-walled section and at least one optical sensor is attached to said thin-walled section. As the thin-walled section flexes in response to a pressure difference across it, the pressure difference is sensed by the optical sensor. The carrier may also have a slot defined on its side wall to receive the optical fiber. A temperature optical sensor may also be provided adjacent to the pressure optical sensor.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A self-powered switching device using a prestressed flextensional electroactive member generates a signal for activation of a latching relay. The electroactive member has a piezoelectric element with a convex and a concave face that may be compressed to generate an electrical pulse. The flextensional electroactive member and associated signal generation circuitry can be hardwired directly to the latching relay or may be coupled to a transmitter for sending an RF signal to a receiver which actuates the latching relay.

Abstract: A pressure responsive mechanically resonant sensor device is provided that comprises a torsion pendulum driven at resonance. The pressure sensor includes a rigid frame to which is affixed a torsion pendulum comprising a hollow tube and a resonant mass as well as optimal means for applying energy to drive the torsion pendulum at resonance. The interior of the hollow tube portion of the torsion pendulum communicates through a pressure port in the rigid frame with the fluid whose pressure is to be sensed. The input pressure affects the torsion constant of the hollow tube and therefor changes the resonant frequency of the torsion pendulum, which frequency is converted into an indication of the sensed pressure.

Abstract: A multi-layer piezoelectric transformer (PT) is provided that is capable of achieving high mechanical momentum and, therefore, is capable of high energy transmission. The PT has a plurality of layers arranged as a composite structure. The outermost portions of the PT comprise the input portions, which are bonded to the central output portion of the PT. The construction and anisotropic nature of the PT allows it to be driven at the longitudinal resonant frequency of the PT corresponding to its overall thickness, which increases the achievable gain and power density of the PT.

Abstract: A piezoelectric transformer is provided having segmented electrodes on one or both faces of a piezoelectric ceramic disk. Application of a voltage sequentially to one or more adjacent segments forms a travelling wave in the disk. Application of a voltage to alternate segments forms a resonant standing wave in the disk. The transformer may be configured with a resonant feedback circuit that provides step up voltage transformation, and may provide voltage to multiple loads.

Abstract: A multi-layer piezoelectric transformer (PT) is provided having an insulation layer having an input electroactive ceramic layer bonded to one of its major faces and an output electroactive ceramic layer bonded to its other major face. The input layer is electroded on both major faces and is poled in the thickness direction. The output layer has segmented electrodes patterned on its two opposing major faces and portions of the output layer are alternatingly poled in opposite directions across the output layer's thickness. The configuration of the poling and electrodes places adjacent portions of the output layer electrically in series.