The disclosed apparatus for sensing the flow of liquid along a passage includes a turbine-type rotor formed of high-resistivity insulation and supported coaxially in the passage. The rotor has spiral vanes distributed about a core. A stator upstream of the rotor provides a spiralling flow pattern in the zone of the rotor. The stator has vanes that spiral in the same direction as the rotor's vanes but at a lower pitch. An electrical sensor provides a varying signal representing the rotation of th...

A CCD frame transfer image sensor wherein the effective integration period can be shortened by electrical means. The sensor comprises an image section having a first photo-sensitive portion of an array of CCD channels and a store section having a second light shielded portion of the array. Means are provided for controlling the potentials applied to the control electrodes of the array so as to transfer along the channels charge generated in the image section into a charge sink structure during o...

A semiconductor sensor adapted to detect with a high degree of sensitivity small magnitudes of a mechanical force, presence of traces of a gas or light. The sensor includes a high energy gap (i.e., .about. 1.0 electron volts) semiconductor wafer. Mechanical force is measured by employing a non-centrosymmetric material for the semiconductor. Distortion of the semiconductor by the force creates a contact potential difference (cpd) at the semiconductor surface, and this cpd is determined to give a ...

An intruder sensor contains a microwave detector and a passive infra-red detector in the same housing. A panel in the housing defines a series of Fresnel lens segments which define the zones for the infra-red sensitive element. The panel also forms the radome for the microwave detector. In the twin horn microwave detector, the infra-red sensitive element is mounted on a circuit board between the horns.

A motion sensor comprising a permanent magnet suspended in pendulum fashion at one end of a length of cord string so as to be capable of swinging freely within an electrical coil when the motion sensor is moved. The movement of the magnet induces an emf in the coil which can be detected by simple electronic circuitry. The motion sensor is extremely simple but yet highly effective to detect both shock movement or a gentle motion.

A system for locating zones defined by Fresnel lens segments or mirror facets of an optical arrangement in a passive infra-red security sensor uses a prism sheet which deflects light emitted by an LED mounted to the circuit board adjacent the infra-red sensitive detector so that it follows the path of infra-red radiation that would be focused onto the element of the detector without the prism sheet present.

An oxygen sensor is disclosed, which includes a planar sensor element and a metallic cover. The planar sensor element is provided with a detecting section at least at one of outer side surfaces thereof for detecting a gas to be measured. The detecting section is protected with the metallic cover. The metallic cover is provided with gas introduction openings for introducing the gas into the metallic cover. The gas introduction openings are arranged so as not to be opposed to the detecting section...

A capacitive force responsive transducer provides a linear relationship between electrical output and input force variations while protecting the sensing diaphragm from damage during extremely high overload forces. In one example differential pressures or forces are applied to opposite sides of a diaphragm interposed between two supporting plates, such that the diaphragm deflects toward one supporting plate and away from the other. Electrodes on opposite sides of the diaphragm are moved opposite...

An electrochemical gas sensor for detecting the amount of a gas or vapor in an atmosphere is described having a sensing electrode and a barrier limiting the rate of access of the gas or vapor to the sensing electrode, the barrier being made of ceramics material and having an inwardly-tapering shape.

An air flow sensor which employs a thermocouple using a film of bismuth.sub.0.92 antimony.sub.0.08 to form junctions with gold, platinum or nickel strips and a resistive strip heater of the same metal.