A fluid mixture parameter determination (FMPD) system for analyzing a fluid mixture while moving includes a computing system and at least one material model that includes two or more model parameters for a plurality of material compositions stored in the memory. An ultrasonic sensor and a millimeter wave (MMW) sensor are each coupled to sense the fluid mixture and are coupled to the computing system. The ultrasonic sensor is for providing ultrasonic data to the computing system including a velocity of the fluid mixture or a volumetric flow, and a velocity of sound (VoS) through the fluid mixture. The MMW sensor is for providing MMW velocity data to the computing system. The computing system is for utilizing the material model together with the ultrasonic data and the MMW velocity data for identifying parameters including a plurality of components in the fluid mixture and a concentration for the plurality of components.

A gas sensor comprises a membrane, a first plate arranged on a first side of the membrane and having through openings for the passage of a gas, a second plate arranged on a second side of the membrane, the second side being situated opposite the first side, and an electronic circuit, which is connected to the membrane, the first plate and the second plate and causes the membrane to emit ultrasonic radiation, and which is configured to determine a resonant frequency of the ultrasonic radiation.

A photoacoustic sensor includes a first layer with an optical MEMS emitter; a second layer stacked over the first layer with a MEMS pressure pick-up and an optically transparent window, wherein the MEMS pressure pick-up and the optically transparent window are offset laterally with respect to one another; and a third layer stacked over the second layer with a cavity for a reference gas. The optical MEMS emitter transmits optical radiation along an optical path, wherein the optical path runs through the optically transparent window and the cavity for the reference gas, and wherein the MEMS pressure pick-up is outside the course of the optical path.

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.

An analyzer determining/classifying aircraft air contaminants using a contaminant collector comprises a microporous medium, a bypass; a sensor generating frequency response when contaminant mass is added to/removed from the sensor, receiving contaminants desorbed from the medium; a first sample flow path, passing through the collector; a second sample flow path, bypassing the collector; a frequency measurement device, measuring response generated by the sensor as contaminant is added to and removed; a computer readable medium bearing a contaminant recognition program and calibration data; and, a processor executing the program, the program including a module classifying the contaminant and measuring response signal magnitudes, and a module using the data for comparison with magnitude of the response generated by the sensor to calculate contaminant concentration and determine a target value for contaminant type, and using measured response magnitudes to adjust first sample flow rates and/or flow durations based upon measured response magnitudes.

The objective of the present invention is to measure gas concentration with a high degree of accuracy. A gas sensor is provided with: a sensor enclosure: an ultrasonic transducer provided at one end of the sensor enclosure; an ultrasonic wave reflecting surface which is provided at the other end of the sensor enclosure and which intersects an axial direction of the sensor enclosure; and a plurality of ventilation holes provided in a side wall of the sensor enclosure. The plurality of ventilation holes are provided at positions such that one side of the sensor enclosure cannot be seen from the other side thereof when viewed from a side surface side of the sensor enclosure, and each ventilation hole has a shape extending in the axial direction of the sensor enclosure.

Disclosed are methods for determining and classifying aircraft air contaminants comprising one or more of: turbine engine oil, hydraulic fluid and deicing fluid using contaminant analyzers comprising a contaminant collector comprising a membrane and a heater vaporizing the contaminants; a gravimetric sensor generating a response when contaminant mass is added to or removed from the sensor, the sensor receiving contaminants desorbed from the heated membrane; a frequency measurement device, measuring the response generated by the sensor as the contaminant is added to and removed from the sensor; a computer readable medium bearing a contaminant recognition program and calibration data; a processor executing the program, the program including a module classifying contaminants by type, and a module using the data for comparison with magnitude of response generated by the sensor to calculate contaminant concentration; and, a pump, generating flow of air through the collector before and after the membrane is heated.

An object of the present invention is to provide a resonant sensor having excellent sensitivity and selectivity with respect to a component to be detected that is contained at a low concentration in the system. A resonant sensor of the present invention has a receiving layer that contains a polymer having a repeating unit represented by Formula (1). In Formula, R.sup.1 represents an alkyl group. A plurality of R.sup.1's may be the same as or different from each other. R.sup.2 represents a hydrogen atom, an alkyl group, or an aryl group. ##STR00001##

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.

[Object] To provide an arithmetic device, an arithmetic method, and a gas detection system that are capable of easily correcting deterioration over time of a detection element.

[Solving Means] The arithmetic device includes a calculation unit. The calculation unit calculates a correction coefficient from a detection element that causes a resonant frequency change by adsorption of gas on the basis of a resonant frequency change amount associated with a humidity change of the detection element in a degraded state and a resonant frequency change amount associated with a humidity change of the detection element in an initial state that was acquired in advance, and corrects the resonant frequency change amount of the detection element in the degraded state by using the correction coefficient.