MONITORING OF CLEARANCE

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. 1. Apparatus for use in monitoring the clearance between a stationary object and one or more moving objects comprising a pair of electrical proximity sensors mounted in relation to the stationary object with their sensitive fields directed towards the path of the moving object(s) and at an angle to each other.2. Apparatus according to wherein said angle is within the range of 15-90°.3. Apparatus according to wherein said fields converge towards each other.4. Apparatus according to wherein said fields diverge from each other.5. Apparatus according to wherein said sensors are eddy current sensors.6. Apparatus according to wherein each said sensor comprises a common coil for use in both generating a magnetic field and detecting the effect of eddy currents generated by said field in such moving object(s).7. Apparatus according to further comprising one or more oscillators for applying alternating currents to each said coil at different frequencies to each other.8. Apparatus according to wherein said coils are wound on intersecting formers.9. (canceled)10. A turbomachine equipped with apparatus according to for use in monitoring the clearance between rotor blade tips and a surrounding casing.11. A gas turbine engine equipped with apparatus according to for use in monitoring the clearance between turbine blade tips and a surrounding casing.12. A method of monitoring the clearance between a stationary object and one or more moving objects ...

REACTANCE MEASUREMENT

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. 1. A reactance measuring apparatus for measuring the reactance of a sensing component in a sensor , comprising:a circuit configured to receive the sensing component and comprising a unit having fixed reactance;an electrical source configured to drive an alternating current through the circuit; andan analysis unit configured to:measure the phase of a signal in the circuit that is dependent on the reactance of the sensing component of the sensor; andoutput a measure of the reactance of the sensing component based on the measured phase.2. The apparatus of claim 1 , whereinthe electrical source is configured to drive the alternating current through the sensing component via the unit having fixed reactance; andthe phase measured by the analysis unit is the phase of a signal generated at a reference point between the sensing component coil and the unit having fixed reactance.3. The apparatus of claim 1 , wherein:the circuit is configured simultaneously to drive equal and opposite alternating currents through the sensing component via respective first and second units having fixed reactance; andthe analysis unit is configured to combine a first signal with a second signal, the first signal being obtained at a first reference point between the sensing component and the first unit, and the second signal being obtained at a second ...

GENERATING TIMING SIGNALS

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. In a disclosed arrangement, a method is provided in which a the sensor is configured to output a signal that is dependent on a separation between a component and the sensor, and the method comprises: performing a first passage event integral of an output from the sensor over at least a portion of a first passage event of a reference component past the sensor; performing a second passage event integral of an output from the sensor over at least a portion of a second passage event of a component to be measured past the sensor, the second passage event occurring after the first passage event; and generating a timing signal when the second passage event integral is equal to a predetermined fraction of the first passage event integral. By integrating the signal, short noise pulses will not cause timing errors. Optionally, only a part of the received signal will be integrated, e.g. portions of the signal which are above the average value of the signal in a preceding period of time. 1. An apparatus for generating a timing signal for registering a passage of a component past a sensor , comprising:the sensor, wherein the sensor is configured to output a signal that is dependent on a separation between a component and the sensor; anda timing signal generation device, wherein the timing signal generation device is configured to:perform a first passage event integral, defined as an integral of an output from the sensor over at least a portion of a first passage event of a reference component past the sensor;perform a second passage event integral, defined as an integral of an output from the sensor over at least a portion of a second passage event of a component ...

Detecting composition of a sample based on thermal properties

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.

DETECTING COMPOSITION OF A SAMPLE BASED ON THERMAL PROPERTIES

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. 1. An apparatus for detecting a composition of a sample , 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 configured to measure a rate of heat transfer through the first surface; anda processing unit configured to analyse 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.2. The apparatus of wherein:the sample is a liquid and the detecting of the composition of the sample comprises detecting contamination of the liquid;the first probe element is configured to provide the first surface in direct contact with the liquid and the second surface not in direct contact with the liquid; andthe processing unit is configured to analyse the measured rate of heat transfer in order to detect a change in a heat transfer characteristic of the liquid that is indicative of contamination of the liquid.3. The apparatus of claim 1 , wherein the first probe element penetrates through a containing wall containing the sample.4. The apparatus of claim 1 , further comprising a first-probe-element heater configured to heat the first probe element.5. The apparatus of claim 1 , wherein the measurement system comprises:a first ...

Fluid driven position sensor

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.

Generating timing signals

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. In a disclosed arrangement, a method is provided in which a the sensor is configured to output a signal that is dependent on a separation between a component and the sensor, and the method comprises: performing a first passage event integral of an output from the sensor over at least a portion of a first passage event of a reference component past the sensor; performing a second passage event integral of an output from the sensor over at least a portion of a second passage event of a component to be measured past the sensor, the second passage event occurring after the first passage event; and generating a timing signal when the second passage event integral is equal to a predetermined fraction of the first passage event integral. By integrating the signal, short noise pulses will not cause timing errors. Optionally, only a part of the received signal will be integrated, e.g. portions of the signal which are above the average value of the signal in a preceding period of time.

Inspection system for coordinate positioning machine

A coordinate measuring machine carries a modular touch trigger probe (100), via an adaptor (200), on its movable arm (10). The probe (100) consists of a retaining module (102) which is mounted to the adaptor (200), and a stylus module (104) which is magnetically connected to the retaining module (102) in a manner which enables the exchange of one stylus module (104) for another. The adaptor consists of a pair of coupling members (202, 204) which are urged into mutual engagement by magnets (212). Automatic exchange of stylus modules occurs by using movement of the arm (10) to disengage a stylus module (104) from the retaining module (102). Similarly, the exchange of one probe for another is carried out by using movement of the arm (10) to disengage the lower coupling member (204) from the upper coupling member (202). Because magnetic attraction between the coupling members (202, 204) is necessarily greater than the attraction between retaining and stylus modules (102, 104), lower coupling member (204) has three levers (222), operable by downward relative movement of a release ring (220), which occurs during uncoupling. The levers (222) provide the mechanical advantage necessary to enable movement of the arm (10) to overcome the relatively large magnetic attraction force between coupling members (202, 204).

Reactance measurement

Generating timing signals

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. In a disclosed arrangement, a method is provided in which a the sensor is configured to output a signal that is dependent on a separation between a component and the sensor, and the method comprises: performing a first passage event integral of an output from the sensor over at least a portion of a first passage event of a reference component past the sensor; performing a second passage event integral of an output from the sensor over at least a portion of a second passage event of a component to be measured past the sensor, the second passage event occurring after the first passage event; and generating a timing signal when the second passage event integral is equal to a predetermined fraction of the first passage event integral. By integrating the signal, short noise pulses will not cause timing errors. Optionally, only a part of the received signal will be integrated, e.g. portions of the signal which are above the average value of the signal in a preceding period of time.

An ozone treatment system

The present invention provides a system for treating a granular organic material with ozone comprises: a processing vessel having an upper end and an opposed lower end, in which the vessel comprises an inlet located at or adjacent the upper end of the vessel. The inlet is configured to supply material from a delivery system to the vessel, and an outlet located at or adjacent the lower end of the vessel. At least one baffle is provided within the vessel, the at least one baffle directs the passage of the material falling from the inlet towards at least one rotating ozone injector. A pressurised supply of ozone gas is configured to pass through the one rotating ozone injector to treat the material with ozone. A separate retrofit system, with its own drive means, is also described in which at least one rotating ozone injector is supported in a hollow housing between a grain store and animal feeding system.

Generating timing signals

Oxidising system

Fluid driven position sensor

Fluid driven position sensor

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.