A flow sensor for producing an electrical signal dependent upon fluid flow has a housing insertable in a bore extending transversely to and intersecting a flow passage in a port plate. A flap pivoted to the housing about an axis transverse to the flow passage is biassed by spring means into a resting position in which the flow passage is obturated. Pivotal movement of the flap from its resting position by fluid flow in the flow passage is converted into an electrical signal by a transducer, such...

An oxygen sensor is composed of or contains a composite solid electrolyte material and, optionally, a body of a non-conducting ceramic material. The composite solid electrolyte material comprises a mixture of at least two constituents, one of which is a good oxygen ion conductor and the other a non-electrolyte ceramic. Magnesium aluminate spinel may be used for the non-conducting ceramic material in the composite solid electrolyte and for the body of the oxygen sensor.

The presence of a signal is sensed by a signal transducer around which an optical fibre is wrapped so that the length of the fibre is modulated by any signal present. A laser supplies coherent light to one end of the fibre and a homodyne detector is provided at the other end. Discontinuities at both ends of the fibre cause multiple reflections which produce differential phase modulations of the signal. The detected signal contains a large number of frequency components and the peak frequency is ...

A temperature sensor comprises a thin layer of niobium nitride with a dis-ordered structure deposited on a thermally conductive electrically insulating substrate and terminal electrical contacts. The layer of niobium nitride may be deposited by reactive cathodic sputtering on the electrically insulating substrate.

A temperature measuring device for measuring temperatures at axially spaced positions along the bore of a tube comprises a sensor in the form of a central rigid wire of constantan base alloy on to which thermocouple foils are spot welded at prescribed locations. The foils are silver plated over half their length thus forming a silver/constantan thermojunction; the constantan end of the junction only being welded to the rigid wire. A copper wire is crimped to the silver plated end of each foil. T...

A verticality sensor comprises a casing within which is mounted a rotary pick-off device having a body attached to the casing and mounted on a shaft for relative rotational movement with respect thereto, such movement producing an output signal from the pick-off representative of the angular rotation of the casing with respect to the vertical, pendulum means mounted on the pick-off shaft for relative rotational movement with respect thereto, and inertia means fixed to the pick-off shaft and coup...

An oxygen sensor is described which includes an electrochemical cell having a gas diffusion electrode which includes a porous metal layer and another layer substantially non-porous to the electrolyte but porous to oxygen, interposed between the porous metal layer and the environment of the sensor as the cathode or working electrode, a salt electrolyte capable of being molten at the temperature of operation of the sensor, a counter electrode as anode, a reference electrode, means for maintaining ...

There is disclosed an improved electrical contact structure between a solid electrolyte galvanic cell and a powder reference material for detecting the oxygen content of molten metals. The solid electrolyte galvanic cell has a portion embedded in the powder reference material and the portion is irregularly shaped so as to increase the contact area and strength of the joint between the embedded portion and the powder reference material.

A composite solid electrolyte material for use in oxygen sensors, which comprises a mixture of at least two ceramic constituents, one of which is a good oxygen ion conductor and the other a non-electrolyte, is useful for oxygen sensor fabrication. Particularly, it enables gas analysis oxygen sensors to be produced by conventional techniques because the coefficient of thermal expansion of the composite electrolyte material can be closely matched to the material of a supporting sensor body. The cl...

In a gas-sensitive resistor of the metal oxide type, the sensitive body is a single crystal of zinc oxide. Such a sensor has particular application in the testing of oxygen-containing atmospheres for the presence of carbon monoxide.