A photoacoustic detection system (20) includes a detector (22) that has a chamber (24), a pulsed light source (26), piezoelectric tuning forks (28), and a photosensor (30). The chamber has an inlet and an outlet for flow of an analyte. The pulsed light source is adjacent the chamber and is operable to emit a light beam along a path through the chamber. The tuning forks are arranged along the path, and each of the tuning forks is operable to emit first sensor signals. The photosensor is arranged along the path and is operable to emit second sensor signals. A controller (38) is connected to receive the first and second sensor signals. The controller is configured to determine whether a target species is present in the analyte based on the first sensor signals and determine whether the target species is present in the analyte based on the second sensor signals.

The present disclosure relates to a photoacoustic gas sensor for detecting the presence or absence of gas using the interaction of a laser beam and gas molecules. The integrated photoacoustic gas sensor according to an embodiment includes a light output unit; a lens unit configured to concentrate a laser beam output from the light output unit; and a photoacoustic sensing unit having a quartz tuning fork aligned on the lens unit and configured to convert a vibration, generated when the laser beam passing through the lens unit interacts with gas molecules, into an electric signal.

Devices, systems, and methods for determining gas characteristics to monitor transformer operation include extracting gas from transformer fluid for analysis.

A measuring device for analyzing a composition of a fuel gas including at least a first gas and a second gas different from the first gas, the first gas and the second gas absorbing an infrared light in at least one common first wavelength range in the electromagnetic spectrum, the measuring device including: an intermittent first infrared emitter; a first sample chamber for receiving the fuel gas; a first detector including at least the first gas and operating according to a photoacoustic effect; and a first filter chamber containing the second gas. The first sample chamber, the first detector, and the first filter chamber are arranged relative to each other such that an infrared light emitted from the first infrared emitter passes through the first sample chamber and the first filter chamber and impinges on the first detector.

The present disclosure provides a gas sensor, including a substrate, a first housing fixed on the substrate and enclosed with the substrate to form a first chamber, and a first infrared transmitter and a first acoustic sensor connected to the substrate. The first acoustic sensor and the first infrared transmitter are housed in the first chamber, and the first housing is provided with a first venthole. The gas sensor also includes an environmental detection assembly connected to the substrate and located outside the first housing, and a differential processor connected to the substrate. The differential processor of the present disclosure can eliminate the ambient sound signal and the vibration signal in the first detection signal according to the second detection signal. Eliminate the strong interference of noise and vibration in the external environment, and improve the accuracy of the gas concentration detection of the gas sensor.

A sensor device and method to determine an amount of gas in the environment. The sensor device comprises at least one transducer. A sensing material (e.g., a metal-organic framework or a polymer film) is disposed on the transducer, and the sensing material captures an amount of the gas that depends on a temperature of the sensing material and a concentration or partial pressure of the gas. At least one detector or readout circuit is arranged to detect responses of the transducer as it captures gas in the sensing material and to output transducer measurement signals indicative of the responses of the transducer. At least one processor is arranged to process (e.g., demodulate) the transducer measurement signals according to the frequency of the temperature modulation. The processor determines the amount of gas according to the demodulated signals.

A photoacoustic sensor (100) is capable of detecting a predefined target gas in an area (Um). A process is capable of detecting the target gas with the use of such a sensor (100). A sample chamber (3) holds a gas sample (Gp) to be tested. Electromagnetic waves (eW) from a radiation source (1) pass through the sample chamber (3) and the detection chamber (4). The waves elicit in the detection chamber (4) an acoustic effect, which is measured by an acoustic sensor (7). The acoustic effect is correlated with the concentration of the target gas in the sample chamber (3). The detection chamber (4) is fluid-tightly sealed, is free from target gas and is filled with a replacement gas (Eg). The transmission of the replacement gas (Eg) has a spectral response similar to that of the transmission of the target gas in a predefined target gas wavelength range.

An emitter structure includes a substrate with a membrane arrangement. The membrane arrangement includes at least one first membrane, a first heating path and a second heating path in different substrate planes. The first heating path and the second heating path are positioned with respect to one another such that a projection of the first heating path and a projection of the second heating path onto a common plane lie at least partly next to one another in the common plane.

An integrated photoacoustic transducer, sensing system and method for assisting in sensing a concentration of a species in a fluid such that the integrated photoacoustic transducer includes a waveguide structure. The waveguide structure has an optical resonance spectrally overlapping a spectral absorption line or band of the species. The photoacoustic transducer includes at least one acoustic cavity formed in a portion of the waveguide structure and configured for receiving the fluid for sensing comprising the species. The at least one acoustic cavity has an acoustic resonance spectrally overlapping with a harmonic of a modulation frequency. At least one acoustic transducer comprising a deformable mechanical portion is included in the photoacoustic transducer. The deformable mechanical portion is in direct acoustic communication with the at least one acoustic cavity and has an adjustable mechanical resonance, which can be brought into spectral overlap with an acoustic resonance of the least one acoustic cavity.

In a first aspect, the invention relates to a photoacoustic gas sensor comprising a gas-fillable detection chamber and a reference chamber arranged laterally adjacent to each other and connected by a sensor channel. A sensor located at or in the sensor channel allows measurement of the photoacoustic signals. Both chambers are preferably located in a plane perpendicular to the emitted IR radiation of the IR emitter which is also comprised. The gas sensor is also formed from a multilayer substrate.

In further aspects, the invention also relates to a method of manufacturing a gas sensor and a method of analyzing gas with a gas sensor.