The application relates to a method for determining a property of a fluid component of a fluid present in a compartment of an electrical apparatus by means of a measurement device arranged outside the compartment and comprising a chamber for receiving a quantity of the fluid from the compartment. Amongst other steps of the method, an optical path in the chamber is illuminated by a light source and a first intensity of light is measured by a light detector. Then fluid is released from the compartment into the chamber and a second intensity (Ix) of light is measured. Based on these measurements the property of the fluid component is determined.

The invention is a method for characterizing a liquid sample, said liquid sample containing particles, the method comprising the following steps: a) illuminating said sample using a light source that is able to emit an incident light wave towards the sample; b) detecting, using a photodetector, a light wave transmitted by the sample thus illuminated; c) characterizing the sample depending on an intensity of the light wave detected by the photodetector.

The method comprises, prior to step c), applying an acoustic wave to the sample, said acoustic wave forming pressure nodes and pressure antinodes in the sample, so as to separate, in the latter, a poor portion, poor in particles, and rich portion, rich in particles, such that, in step c), the sample is characterized: either on the basis of the intensity of the light wave transmitted by the poor portion; or on the basis of the intensity of the light wave transmitted by the rich portion.

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

A photonic quantum dew point sensor determines a dew point of an analyte and includes a common substrate; a photonic dew sensor on the common substrate and exposed for direct contact with the analyte; a photonic temperature sensor on the common substrate; an optomechanical temperature sensor on the common substrate; a dew sensor substrate interposed between the photonic dew sensor and the common substrate; a heater on the dew sensor substrate proximate to the photonic dew sensor; a temperature sensor substrate interposed between the common substrate and each of the photonic temperature sensor and the optomechanical temperature sensor; and a sensor cover on the photonic temperature sensor, the optomechanical temperature sensor, and the temperature sensor substrate to cover the photonic temperature sensor and the optomechanical temperature sensor to prevent direct contact between the analyte and each of the photonic temperature sensor and the optomechanical temperature sensor.

The application relates to a method for determining a property of a fluid component of a fluid present in a compartment of an electrical apparatus by means of a measurement device arranged outside the compartment and comprising a chamber for receiving a quantity of the fluid from the compartment. Amongst other steps of the method, an optical path in the chamber is illuminated by a light source and a first intensity of light is measured by a light detector. Then fluid is released from the compartment into the chamber and a second intensity (Ix) of light is measured. Based on these measurements the property of the fluid component is determined.

A photonic quantum dew point sensor determines a dew point of an analyte and includes a common substrate; a photonic dew sensor on the common substrate and exposed for direct contact with the analyte; a photonic temperature sensor on the common substrate; an optomechanical temperature sensor on the common substrate; a dew sensor substrate interposed between the photonic dew sensor and the common substrate; a heater on the dew sensor substrate proximate to the photonic dew sensor; a temperature sensor substrate interposed between the common substrate and each of the photonic temperature sensor and the optomechanical temperature sensor; and a sensor cover on the photonic temperature sensor, the optomechanical temperature sensor, and the temperature sensor substrate to cover the photonic temperature sensor and the optomechanical temperature sensor to prevent direct contact between the analyte and each of the photonic temperature sensor and the optomechanical temperature sensor.

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

A gas detection system, comprising a sample gas inlet, a reference gas inlet and a gas modulation valve alternatingly connecting one of the sample gas inlet and the reference gas inlet to a gas sensor, is characterized in that a selective transfer filter is located in the gas flow path connecting the gas modulation valve and the gas sensor.

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

A gas detection system, comprising a sample gas inlet, a reference gas inlet and a gas modulation valve alternatingly connecting one of the sample gas inlet and the reference gas inlet to a gas sensor, is characterized in that a selective transfer filter is located in the gas flow path connecting the gas modulation valve and the gas sensor.