Abstract: An acoustic gas analyzer for gas mixture has an acoustic velocity meter that provides a first output dependent on a detected transmission of acoustic energy through a gas to be analyzed, a temperature probe having a probe time constant that provides a second output indicative of a measured temperature of the gas, and a calculation unit that receives the first and the second outputs and determines compositional information of the gas therefrom. A signal processor is connected between the acoustic velocity meter and the calculation unit and temporally adapts the amplitude of the first output from the meter in a manner dependent on the probe time constant and provides a temporally adapted first output for use as the first output within the calculation unit.

Abstract: A mechanical breathing aid has first and second inlets respectively connectable to a source of air and a source of oxygen. A mixing location is in gaseous communication with the first and second inlets, at which controlled amounts of air and oxygen from the respective inlets are mixed. An acoustic analyzer operates during a measurement procedure to access a moisture content value for air from the source of air, to generate acoustic velocity-related information from acoustic energy interaction with the breathing gas, and to determine therefrom an oxygen content. The analyzer operates during a calibration procedure to generate acoustic velocity-related information from acoustic energy interaction with air from the source of air, and to determine therefrom an oxygen content value for the air from which is determined a moisture content value for air.

Abstract: In a calibration apparatus and method for a resistance thermometer a reference thermometer is located in thermal contact with a gas composition to generate, during a calibration period, a first reference temperature value for the gas composition at a first temperature, and an acoustic meter is located in acoustic contact with the gas composition and, during the calibration period, makes an acoustic velocity-related measurement for use in generating a second reference temperature value for the gas composition at a second temperature. A calibration unit coordinates the first and second reference temperature values with first and second measurement temperature values provided by the resistance thermometer at the first and the second temperatures, respectively, and establishes a calibration relationship therefrom.

Abstract: An acoustic meter assembly has a measurement chamber for receiving a pressurized fluid to be monitored; an acoustic transducer for transmitting acoustic energy into and receiving the transmitted energy from the measurement chamber; and a holder for the acoustic transducer including a receiving section in which the acoustic transducer is locatable to expose a front surface to fluid pressure within the measurement chamber. The holder further has a pressure transfer arrangement for communicating pressure between the measurement chamber and a rear surface of the transducer, opposite to the front surface.

Abstract: An acoustic gas monitor has a measurement chamber into which a reference gas of known composition is received and is provided with a wall section for the selective transmission of a gaseous substance to be monitored between the reference gas internal the chamber and a host gas externally of the chamber. An acoustic velocity meter is arranged to supply to an analyzer a signal indicative of an acoustic velocity within the mixture of reference gas and gaseous substance in the chamber. The analyzer being programmed to derive, from the velocity measurement made within the single chamber, information relating to the level of the gaseous substance to be monitored.

Abstract: An acoustic gas meter has an acoustic transmitter/receiver arrangement disposed within a gas flow conduit for transmitting and receiving acoustic energy along an acoustic path. A temperature probe has an elongate sensor region disposed relative to, preferably along, the acoustic path to provide a measure of a gas temperature indicative of an average gas temperature within the acoustic path.

Abstract: A mechanical breathing aid has first and second inlets respectively connectable to a source of air and a source of oxygen. A mixing location is in gaseous communication with the first and second inlets, at which controlled amounts of air and oxygen from the respective inlets are mixed. An acoustic analyzer operates during a measurement procedure to access a moisture content value for air from the source of air, to generate acoustic velocity-related information from acoustic energy interaction with the breathing gas, and to determine therefrom an oxygen content. The analyzer operates during a calibration procedure to generate acoustic velocity-related information from acoustic energy interaction with air from the source of air, and to determine therefrom an oxygen content value for the air from which is determined a moisture content value for air.

Abstract: In a calibration apparatus and method for a resistance thermometer a reference thermometer is located in thermal contact with a gas composition to generate, during a calibration period, a first reference temperature value for the gas composition at a first temperature, and an acoustic meter is located in acoustic contact with the gas composition and, during the calibration period, makes an acoustic velocity-related measurement for use in generating a second reference temperature value for the gas composition at a second temperature. A calibration unit coordinates the first and second reference temperature values with first and second measurement temperature values provided by the resistance thermometer at the first and the second temperatures, respectively, and establishes a calibration relationship therefrom.

Abstract: An acoustic gas analyzer for gas mixture has an acoustic velocity meter that provides a first output dependent on a detected transmission of acoustic energy through a gas to be analyzed, a temperature probe having a probe time constant that provides a second output indicative of a measured temperature of the gas, and a calculation unit that receives the first and the second outputs and determines compositional information of the gas therefrom. A signal processor is connected between the acoustic velocity meter and the calculation unit and temporally adapts the amplitude of the first output from the meter in a manner dependent on the probe time constant and provides a temporally adapted first output for use as the first output within the calculation unit.

Abstract: An acoustic meter assembly has a measurement chamber for receiving a pressurized fluid to be monitored; an acoustic transducer for transmitting acoustic energy into and receiving the transmitted energy from the measurement chamber; and a holder for the acoustic transducer including a receiving section in which the acoustic transducer is locatable to expose a front surface to fluid pressure within the measurement chamber. The holder further has a pressure transfer arrangement for communicating pressure between the measurement chamber and a rear surface of the transducer, opposite to the front surface.

Abstract: In a method and apparatus for monitoring the composition of a breathing gas mixture having a first gaseous component and a second gaseous component, a data processor is supplied, either as an input value or as a measured value from associated humidity sensors with an indication of a moisture content value (RHComp1) for the first gaseous component and a moisture content value (RHComp2) second gaseous component before mixing. An indication of the moisture content value for the mixture (RHMix) is measured and provided to the data processor. From these inputs the data processor determines a value indicative of the amount (x,y) of one or both of the first gaseous component and the second gaseous component in the mixture according to the relationship: RHComp1·x+RHComp2·y=RHMix.

Abstract: In a method and apparatus for monitoring the composition of a breathing gas mixture having a first gaseous component and a second gaseous component, a data processor is supplied, either as an input value or as a measured value from associated humidity sensors with an indication of a moisture content value (RHComp1) for the first gaseous component and a moisture content value (RHComp2) second gaseous component before mixing. An indication of the moisture content value for the mixture (RHMix) is measured and provided to the data processor. From these inputs the data processor determines a value indicative of the amount (x,y) of one or both of the first gaseous component and the second gaseous component in the mixture according to the relationship: RHcomp1·x+RHcomp2·y=RHMix.

Abstract: An acoustic gas monitor has a measurement chamber into which a reference gas of known composition is received and is provided with a wall section for the selective transmission of a gaseous substance to be monitored between the reference gas internal the chamber and a host gas externally of the chamber. An acoustic velocity meter is arranged to supply to an analyzer a signal indicative of an acoustic velocity within the mixture of reference gas and gaseous substance in the chamber. The analyzer being programmed to derive, from the velocity measurement made within the single chamber, information relating to the level of the gaseous substance to be monitored.

Abstract: An acoustic gas meter has an acoustic transmitter/receiver arrangement disposed within a gas flow conduit for transmitting and receiving acoustic energy along an acoustic path. A temperature probe has an elongate sensor region disposed relative to, preferably along, the acoustic path to provide a measure of a gas temperature indicative of an average gas temperature within the acoustic path.