Abstract: The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

Abstract: Apparatus and methods for reactance measurements are disclosed. The apparatus and methods are particularly suitable for eddy current proximity sensors in turbo-machine assemblies. In one arrangement, there is provided an apparatus comprising a circuit for receiving a sensing component of a sensor. The circuit has a unit having fixed reactance. An electrical source is provided for driving an alternating current through the circuit. An analysis unit measures the phase of a signal in the circuit that is dependent on the reactance of the sensing component. A measure of the reactance of the sensing component is output based on the measured phase.

Abstract: The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

Abstract: The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

Abstract: Methods and apparatus for measuring the position of an object relative to a reference are disclosed. In an arrangement, a pressurized fluid is used to drive rotation of a cylinder around a piston and to bias the cylinder longitudinally. Ducts are provided in the cylinder and arranged so at to provide pulses of the fluid out of the cylinder through a reading port, the pulses being such as to uniquely identify the position of the cylinder relative to the piston and thereby of the object relative to the reference.

Abstract: Apparatus and methods for reactance measurements are disclosed. The apparatus and methods are particularly suitable for eddy current proximity sensors in turbo-machine assemblies. In one arrangement, there is provided an apparatus comprising a circuit for receiving a sensing component of a sensor. The circuit has a unit having fixed reactance. An electrical source is provided for driving an alternating current through the circuit. An analysis unit measures the phase of a signal in the circuit that is dependent on the reactance of the sensing component. A measure of the reactance of the sensing component is output based on the measured phase.

Abstract: The invention relates generating timing signals registering the passage of a component past a sensor. The invention relates particularly to the generation of timing signals in real time for health monitoring of a mechanical system, for example for detecting excessive distortion or vibration of rotor blades in a turbine.

Abstract: The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

Abstract: The invention relates generating timing signals registering the passage of a component past a sensor. The invention relates particularly to the generation of timing signals in real time for health monitoring of a mechanical system, for example for detecting excessive distortion or vibration of rotor blades in a turbine.

Abstract: Methods and apparatus for measuring the position of an object relative to a reference are disclosed. In an arrangement, a pressurized fluid is used to drive rotation of a cylinder around a piston and to bias the cylinder longitudinally. Ducts are provided in the cylinder and arranged so at to provide pulses of the fluid out of the cylinder through a reading port, the pulses being such as to uniquely identify the position of the cylinder relative to the piston and thereby of the object relative to the reference.

Abstract: The clearance between a stationary object (such as a gas turbine engine casing) and one or more moving objects (such as the blades of a rotating turbine) is measured using a pair of electrical proximity sensors mounted on the stationary object with their sensitive fields directed towards the path of the moving object(s) and at angle to each other. The clearance is calculated by deriving a time interval between interceptions of the respective moving object with the sensitive fields of the two sensors and from the geometry of the set up.