An environment detection system includes a sound wave transmitter, a sound wave receiver, and a control unit. The sound wave transmitter transmits a detection sound wave to a target space. The sound wave receiver receives the detection sound wave transmitted by the sound wave transmitter. The control unit controls the sound wave transmitter. The environment detection system detects at least either a temperature distribution or an air velocity distribution in the target space. The control unit executes a first control to regulate at least either a volume or a frequency of the detection sound wave transmitted by the sound wave transmitter so that a volume of the detection sound wave received by the sound wave receiver is higher than or equal to a predetermined reference reception volume.

A method for the measurement of the speed of sound in a gas suitable for the determination of gas characteristics, especially the composition of the gas, the temperature and/or the humidity of the gas, and a speed of sound based gas sensor arrangement adapted to measure that gas characteristics comprising sound sending means and sound receiving means and signal processing unit. A sound sender is used as sound sender and a first sound receiver and a second sound receiver as sound receiving means, all three of them being arranged such that the travel distance of the sound provided by the sender to the first receiver is different from the travel distance of the sound provided by the sender to the second receiver. Further the arrangement includes the signal processing means connected with the sender and the receivers which operate the sender and determine gas characteristics, especially the composition of the gas, the temperature and/or the humidity of the gas, from the different signals provided by the first and the second receiver.

A respiratory flow therapy apparatus including a sensor module can measure a flow rate of gases or gases concentration provided to a patient. The sensor module can be located after a blower and/or mixer. The sensor module can include at least an ultrasonic transmitter, a receiver, a temperature sensor, a pressure sensor, a humidity sensor and/or a flow rate sensor. The receivers can be immersed in the gases flow path. The receivers can cancel delays in the transmitters and improve accuracy of measurements of characteristics of the gases flow. The receivers can allow for detection of a fault condition in a blower motor of the apparatus.

A MEMS device for detecting particulate and gases in the air, comprising: a first semiconductor body; a second semiconductor body with a first surface facing a first surface of the first semiconductor body; and a first spacer element and a second spacer element, which extend between the first surfaces of the semiconductor bodies so as to arrange them at a distance apart from one another and define a first duct. The MEMS device further comprises at least one of the following: a first particulate sensor comprising a first emitter unit for generating acoustic waves in the first duct, and a first particulate-detection unit for detecting the particulate, the first emitter unit and the first particulate-detection unit facing one another through the first duct; and a first gas sensor, which faces the first duct and is configured to detect said gases in the air present in the first duct.

An environment detection system includes a sound wave transmitter, a sound wave receiver, and a determination unit. The sound wave transmitter transmits a detection sound wave to a target space where an environment control device that conditions air in a space is installed. The sound wave receiver receives the detection sound wave transmitted by the sound wave transmitter. The determination unit determines a temperature or an air velocity in a first region near the environment control device, based on predetermined acquired information acquired from the environment control device. The environment detection system obtains a temperature or air velocity distribution in the target space, based on measured sound wave data. A temperature or air velocity distribution in a second region is obtained based on at least either the temperature or the air velocity in the first region determined by the determination unit and the measured sound wave data.

The present disclosure relates to a system and a method for gas fingerprinting. The system includes multiple holders having a distinct gas-permeable membrane disposed of therewithin such that a confined space is created behind the membranes. The test gas is pressurized in a single gas reservoir and is allowed to permeate through the membranes into respective confined spaces. The accumulated pressure values behind the utilized membranes (in the confined spaces) at a given time, are simultaneously recorded using pressure sensors. The recorded gas accumulation data is processed by a computing device to determine a characteristic property for each test gas. The system ability to fingerprint gases is demonstrated by ten test gases including helium, neon, argon, hydrogen, nitrogen, carbon dioxide, methane, ethane, propane, and ethylene, and is also able to discriminate between closely related gases.

To provide an odor sensor capable of using an additive that was not capable of being adopted in an odor sensor including a polymer film, an odor measurement system using the odor sensor, and a method for producing the odor sensor, an odor sensor comprises a plurality of sensor elements, the sensor element including a substance absorption film adsorbing an odor substance; and a detection unit detecting adsorption of the odor substance with respect to the substance absorption film, wherein the substance absorption film is a porous fine particle film that contains fine particles containing a compound having silicon and oxygen as a skeleton, and a surface modifier for modifying surfaces of the fine particles, and in at least a part of the plurality of sensor elements, compositions of the fine particles and/or the surface modifier are different from each other.

A measurement apparatus comprises a memory that stores instructions. The measurement apparatus comprises a processor that executes the instructions stored in the memory to: identify a propagation distance which is a length of a propagation path that a sound wave transmitted from a transmitting apparatus takes before reaching a receiving apparatus; determine, based on the identified propagation distance, a method to be used to identify a propagation time for the sound wave transmitted from the transmitting apparatus to reach the receiving apparatus from among a plurality of methods for identifying a propagation time of a sound wave; identify the propagation time for the sound wave transmitted from the transmitting apparatus to reach the receiving apparatus by the determined method; and measure an air characteristic of a location on the propagation path based on the identified propagation time and the identified propagation distance.

A gas analyzer uses continuous sonic signals through a conduit to determine the composition of a gas in the conduit. A transmitting transducer drives sonic signals at a fixed frequency and a second transducer receives the sonic signals. The phase shift between two signals corresponds to the speed of sound through the gas and is related to the composition of the gas. The electronic versions of these signals are processed by lowering, or dividing, the fixed frequency which expands the range of phase shift measurement and allows the determination of an expanded range for the gas composition. In an ozone generation system, the gas analyzer is highly suitable for determining the composition of gases derived from air as a gas of known composition and a calibration point.

A method for determining properties of a hydrocarbon-containing gas mixture includes determining a thermal conductivity value, density measurement, viscosity measurement, and temperature and pressure. The method also includes determining a hydrogen content of the gas mixture on the basis of the thermal conductivity value and the temperature and pressure, determining a density measurement and associated temperature and pressure, and determining the mean molar mass or standard density on the basis of the density measurement and the temperature and pressure. The method further includes determining the mean molar mass or standard density of a hydrogen-free residual gas mixture based on the mean molar mass or standard density and the hydrogen fraction, determining the Wobbe index of the residual gas mixture based on the viscosity measurement and the temperature and pressure, and determining a calorific value based on the mean molar mass or standard density and the Wobbe index.