Abstract: A probe comprises a resistive element configured to be brought into thermal contact with an entity to be sensed. A measurement system applies a plurality of heating pulses to the resistive element by driving an electrical current through the resistive in element and measures an electrical response of the resistive element to the heating pulses in order to determine information about either or both of the composition and state of the entity. The measurement system generates an output signal using the measured electrical response, wherein the output signal is generated by progressively offsetting the measured electrical response such that, in the event of an average temperature of the resistive element changing between different heating pulses due to a drift in the average temperature of a portion of the entity being sensed, a variance over the plurality of heating pulses of a value of the output signal at a predetermined common reference point within each heating pulse is reduced.

Abstract: The invention relates to sensing compositional information about material by measuring thermal properties of the material. In one arrangement there is provided a needle probe for sensing compositional information. The probe comprises a needle having a tip region. A resistive element is attached to the needle at the tip region. A measurement system is configured to: 1) drive an electrical current through the resistive element to apply heating to the resistive element, and 2) measure an electrical response of the resistive element to the heating. A processing unit analyses the measured electrical response of the resistive element to the heating to determine compositional information about material in contact with the tip region.

Abstract: An energy recovery system and a method of recovering energy are disclosed. In one arrangement, an exhaust gas conduit system guides a flow of exhaust gas generated by a combustion process. A heat exchange fluid circuit guides a flow of a heat exchange fluid. An electrical generator generates electrical power from the flow of heat exchange fluid. The heat exchange fluid circuit is configured so that heat is transferred from the exhaust gas to the heat exchange fluid while the exhaust gas is flowing through the exhaust gas conduit system.

Abstract: The invention relates to sensing compositional information about material by measuring thermal properties of the material. In one arrangement there is provided a needle probe for sensing compositional information. The probe comprises a needle having a tip region. A resistive element is attached to the needle at the tip region. A measurement system is configured to: 1) drive an electrical current through the resistive element to apply heating to the resistive element, and 2) measure an electrical response of the resistive element to the heating. A processing unit analyses the measured electrical response of the resistive element to the heating to determine compositional information about material in contact with the tip region.

Abstract: A sensor element (4) is used to apply a heating pulse to a pharmaceutical product (6). Chemical or structural information about the pharmaceutical product is determined by measuring a response of the sensor element (4) during the heating pulse. The response is dependent on a heat transfer characteristic of the pharmaceutical product (6).

Abstract: Apparatus and methods for electrosurgery are disclosed. In one arrangement, an electrosurgical element and a control system are provided. The electrosurgical element is electrically driven in a first electrical driving mode. The first electrical driving mode is such as to cause heating of human or animal tissue by the electrosurgical element. The heating contributes to modification or cutting of tissue by the electrosurgical element. The electrosurgical element is electrically driven in a second electrical driving mode. An electrical response of the electrosurgical element is measured during the electrical driving of the electrosurgical element in the second electrical driving mode.

Abstract: The invention provides an apparatus and a method for testing a sample, with a sensor element (4) comprising a first conductor (301), a second conductor (302) and a third conductor (303) in series. The first conductor (301) is connected to the second conductor (302) at a first sensing junction (316A) and the second conductor (302) is connected to the third conductor (303) at a second sensing junction (316B). Heating is applied to a sample via Joule heating in the second conductor (303). A thermal response is measured (12) via a potential difference between the first conductor and the third conductor generated by the Seebeck effect.

Abstract: An energy recovery system and a method of recovering energy are disclosed. In one arrangement, an exhaust gas conduit system guides a flow of exhaust gas generated by a combustion process. A heat exchange fluid circuit guides a flow of a heat exchange fluid. An electrical generator generates electrical power from the flow of heat exchange fluid. The heat exchange fluid circuit is configured so that heat is transferred from the exhaust gas to the heat exchange fluid while the exhaust gas is flowing through the exhaust gas conduit system.

Abstract: Methods of sensing a dental region are disclosed. In one arrangement, a sensor element is used to apply a heating pulse to the dental region. Chemical or structural information about the dental region is determined by measuring a response of the sensor element during the heating pulse. The response is dependent on heat transfer characteristics of the dental region.

Abstract: A probe comprises a resistive element configured to be brought into thermal contact with an entity to be sensed. A measurement system applies a plurality of heating pulses to the resistive element by driving an electrical current through the resistive element and measures an electrical response of the resistive element to the heating pulses in order to determine information about either or both of the composition and state of the entity. The measurement system generates an output signal using the measured electrical response, wherein the output signal is generated by progressively offsetting the measured electrical response such that, in the event of an average temperature of the resistive element changing between different heating pulses due to a drift in the average temperature of a portion of the entity being sensed, a variance over the plurality of heating pulses of a value of the output signal at a predetermined common reference point within each heating pulse is reduced.

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: A sensor element (4) is used to apply a heating pulse to a pharmaceutical product (6). Chemical or structural information about the pharmaceutical product is determined by measuring a response of the sensor element (4) during the heating pulse. The response is dependent on a heat transfer characteristic of the pharmaceutical product (6).

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: The invention relates to a method of measuring turbulence in a high temperature fluid flow, comprising: applying different levels of cooling at different times to a region of a substrate in the high temperature fluid flow; and/or applying different levels of cooling at the same time to different regions of a substrate in the high temperature fluid flow and/or to regions on different substrates in the high temperature fluid flow, wherein the method further comprises: measuring fluctuations in the temperature of the region or regions of the substrate or substrates at each of the different levels of cooling; and using the measured fluctuations to determining an amount of turbulence in the high temperature fluid flow and/or the size of temperature fluctuations in the high temperature fluid flow.

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: A rotor assembly has a sealing system for sealing at apexes or faces of the rotor. An apex seal or face seal comprises a compliant member that is configured such that the shape or orientation of the compliant member can change in use in response to a change in the speed of rotation of the rotor, a change in the pressurization across the compliant member, or a change in clearance between the sealing surface and a mounting element to which the compliant member is mounted, to deflect towards or away from the sealing surface.

Abstract: The invention relates to sensing compositional information about material by measuring thermal properties of the material. In one arrangement there is provided a needle probe for sensing compositional information. The probe comprises a needle having a tip region. A resistive element is attached to the needle at the tip region. A measurement system is configured to: 1) drive an electrical current through the resistive element to apply heating to the resistive element, and 2) measure an electrical response of the resistive element to the heating. A processing unit analyses the measured electrical response of the resistive element to the heating to determine compositional information about material in contact with the tip region.

Abstract: A method for monitoring local defects in a rotating engine component such as a gear uses one or more eddy current sensor(s) arranged to interact with the engine component as it is rotating during service. The eddy current sensor(s) may be carried by one or more teeth of a monitoring gear. A device is arranged to measure an output signal from the eddy current sensor(s) resulting from interaction with the rotating engine component. The output signal is processed so as to detect a change in shape of the output signal indicative of a local defect.