Abstract: A system for an icing resistant sensor port assembly includes shaped and patterned features for resisting the formation and propagation of ice around a sensor port, such as for a pressure sensor in an aircraft fuel tank. Water may be present in fuel tanks due to condensation and other factors. The water, being heavier than fuel, such as jet fuel, sinks to the bottom of the tank and may be present around the sensor port. If the water completely fills the pressure port, it may damage the sensor. In various embodiments, an inlet assembly having a cone-shaped countersink, sharp edges that reduce surface area, anti-wetting coatings, and slots to allow fluid flow within the inlet assembly, among other features, may be used to help resist ice formation and propagation around a sensor port.

Abstract: A proximity sensor assembly includes a multilayer printed wiring board proximity sensor, the proximity sensor being operable as either a variable-reluctance sensor or an eddy current loss sensor. The proximity sensor includes a plurality of layers configured to form at least one wound coil disposed about at least a portion of a core. The coils are electrically driven to generate an alternating magnetic field such that the inductance of the coils changes when a permeable or conductive object is moved in relation to the magnetic field. The change in inductance is recognized and used to detect the proximity and presence of an object relative to the sensor.

Abstract: A method of fabricating a multilayer wiring board proximity sensor includes forming a laminate, and fabricating a plurality of through-conductors through the layers of the laminate. The laminate has a plurality of layers including one or more core layers and a plurality of coil layers. Each core layer includes a core pattern formed of a permeable material, and each coil layer comprises at least one coil trace formed of a conducting material. Thus, the through-conductors may be fabricated through the layers of the laminate such that the coil traces are interconnected by the through-conductors to thereby form one or more coils disposed about at least a portion of the core patterns of the core layers.

Abstract: An inductive proximity sensor comprises: a housing including an opening on one side; an inductive core including two legs, each core leg including a foot portion; an inductive coil wound bobbin disposed about each leg of the core, each bobbin including an integral ledge cantilevered from an inside surface of the bobbin for forming a pocket under the integral ledge at a bottom of the bobbin for containing the foot portion of the corresponding core leg; a thruster element including a top surface and two legs, each thruster leg disposed into a respective bobbin resting on the integral ledge thereof, the core, wound bobbins and thruster element disposed in the housing; a spring element disposed on the top surface of the thruster element at the housing opening; and a housing cover disposed over the housing opening for compressing the spring element against the thruster element which renders the core and wound bobbins in a fixed relationship to each other in the housing.

Abstract: An ultrasonic transducer is disclosed comprising a layer of piezoresonator material capable of transmitting from a top surface thereof an ultrasonic pulse into a tank of liquid and receiving at the top surface reflections of the transmitted pulse from the liquid; and a matching layer of pure crystalline Boron Nitride disposed on the top surface. The pure crystalline Boron Nitride layer is operative to match the acoustic impedances of the piezoresonator material and the tank liquid about the operational frequency passband of the ultrasonic pulse. The ultrasonic transducer may be disposed in an assembly for measuring a quantity of liquid in the tank.

Abstract: Apparatus for detecting relative displacement includes a first magnet for producing a first magnetic field along an axis; a second magnet for producing a second magnetic field along the axis; the first and second magnetic fields interacting to produce a position-dependent magnetic field along the axis; a sensor disposed for detecting the position-dependent magnetic field; and a movable element for causing relative displacement between the position-dependent magnetic field and the sensor. In a preferred embodiment, the sensor is a magneto-optic sensor.

Abstract: Apparatus for detecting ferromagnetic debris in a fluid medium in a container includes a plug attachable to the container and having an associated magnetic field preferably produced by a permanent magnet. The plug is at least partly exposed to the fluid to capture debris in the fluid. The apparatus further includes a portable sensor for optically sensing the captured debris, with the sensor having a probe that is connectable to the plug. A method for using such apparatus is provided, and in general a method of detecting ferromagnetic particles in a fluid medium in a container includes the steps of: a) magnetically capturing particles from the fluid using a plug with the container, and b) interrogating the plug with light for captured particles using a portable probe.