A chemical vapor deposition or atomic layer deposition system includes a gas concentration sensor for determining the quantity of precursor gases admitted thereto. The gas concentration sensor can include a transmitter and a receiver for transmitting an acoustic signal across a chamber. In embodiments, the transmitter and receiver are designed to increase transmitted signal while reducing transmitted noise, facilitating use of the gas concentration sensor at low pressure and high temperature.

In accordance with embodiments there is proposed an ultrasound sensor device and an ultrasound sensor system configured to perform a method using ultrasound to determine a ratio or concentration of respective gases in a flow of mixed gases. There is provided a method to adapt a distribution system with an ultrasound sensor device and/or an ultrasound sensor system.

Systems and methods for material composition detection includes a vessel containing a quantity of a fluid composition therein which has at least a first and second fluids. At least one acoustic transducer is positioned on an exterior sidewall of the vessel. A computerized device has a processor and is in communication with the acoustic transducer. A metric of a property of the first fluid is determined based on a first signal of the acoustic transducer. A metric of a property of the second fluid is determined based on a second signal of the acoustic transducer. A metric of a property of the fluid composition at a point in time is determined based on the metrics of the first and second fluids, and at least a determinable volume of at least a portion of the vessel. A material identity of the fluid composition is determined at the point in time.

A collimated beam (23) of a surface acoustic wave propagates on a piezoelectric substrate (22) while passing through sensitive film (25) to adsorb a sensing gas. Signal processing unit (40) transmits an exciting burst signal to sensor electrode (24) to excite the collimated beam (23), receives first and second returned burst signals after the collimated beam (23) has propagated, and calculates a target gas parameter by a target leakage factor of the background gas and a relation between reference gas parameters and reference leakage factors of reference gases, the leakage factor is provided by first and second attenuations of the first and second returned burst signals, respectively, using waveform data of the first and second returned burst signals.

A gas sensor includes: a main elongate gas chamber with a supply opening arranged on a first end of the main gas chamber and a discharge opening positioned opposite the supply opening and arranged on a second end of the main gas chamber, to permit gas to flow through the main gas chamber; a magnetic field device providing a magnetic field in the main gas chamber; and an ultrasonic transmitter and receiver sensor arranged on either the first or second end of the main elongate gas chamber for directing an ultrasonic wave along a longitudinal axis of the main elongate gas chamber, an opposite end of the main elongate gas chamber being reflective for an ultrasonic wave, or an ultrasonic transmitter sensor arranged on a first end of the main elongate gas chamber and an ultrasonic receiver sensor arranged on a second end of the main elongate gas chamber.

A gases humidification system includes a measuring chamber and a mixing chamber. The mixing chamber has one or more mixing elements that improve a mixing of gases before reaching the measuring chamber. Ultrasonic sensing is used to measure gases properties or characteristics within the measuring chamber. A baffle or a vane may be used to control and direct the gases flow through the mixing chamber as the gases flow moves into the measuring chamber.

A gases humidification system includes a measuring chamber and a mixing chamber. The mixing chamber has one or more mixing elements that improve a mixing of gases before reaching the measuring chamber. Ultrasonic sensing is used to measure gases properties or characteristics within the measuring chamber. A baffle or a vane may be used to control and direct the gases flow through the mixing chamber as the gases flow moves into the measuring chamber.

A respiratory assistance apparatus has a gases inlet configured to receive a supply of gases, a blower unit configured to generate a pressurised gases stream from the supply of gases; a humidification unit configured to heat and humidify the pressurised gases stream; and a gases outlet for the heated and humidified gases stream. A flow path for the gases stream extends through the respiratory device from the gases inlet through the blower unit and humidification unit to the gases outlet. A sensor assembly is provided in the flow path before the humidification unit. The sensor assembly has an ultrasound gas composition sensor system for sensing one or more gas concentrations within the gases stream.

An acoustic sensor, comprising: a side wall, closed by first and second end walls to form a substantially cylindrical cavity for containing a fluid, wherein a radius, a, of the cavity and an axial height, h, of the cavity satisfies the inequality a/h is greater than 1.2; a transmitter, operatively associated with one of the first and second end walls; a receiver, operatively associated with the other of the first and second end walls; and a first stiffener plate, comprising an outer peripheral edge and an aperture which defines an inner peripheral edge, and located on an outer face of the first end wall such that the aperture overlies the axis of the cavity; wherein: the first end wall comprises at least one through-hole, located radially of the axis of the cavity between the inner and outer peripheral edges of the first stiffener plate; the first stiffener plate comprises at least one duct, which connects the at least one through-hole, of the first end wall, to at least one of the inner and outer peripheral edges of the first stiffener plate, thereby to provide at least one fluid passageway between the cavity and the external surroundings of the acoustic sensor via the first end wall; and in use: the transmitter causes oscillatory motion, of the one of the first and second end walls with which the transmitter is associated, in a direction substantially perpendicular to the plane of that end wall, such that axial oscillations of that end wall drive substantially radial oscillations of a fluid pressure in the cavity; and the substantially radial oscillations in the pressure of the fluid drive oscillatory motion of the other of the first and second end walls, with which the receiver is associated, generating an electrical signal.

A respiratory assistance apparatus has a gases inlet configured to receive a supply of gases, a blower unit configured to generate a pressurised gases stream from the supply of gases; a humidification unit configured to heat and humidify the pressurised gases stream; and a gases outlet for the heated and humidified gases stream. A flow path for the gases stream extends through the respiratory device from the gases inlet through the blower unit and humidification unit to the gases outlet. A sensor assembly is provided in the flow path before the humidification unit. The sensor assembly has an ultrasound gas composition sensor system for sensing one or more gas concentrations within the gases stream.