A reference chamber for a fluid sensor comprises a housing, a deflectable structure, which is arranged movably within the housing, a control device configured to drive the deflectable structure at a first point in time such that the deflectable structure assumes a defined position, and to drive the deflectable structure at a second point in time such that the deflectable structure moves out of the defined position and a movement of the deflectable structure in the housing is obtained. The reference chamber comprises an evaluation device configured to determine a movement characteristic of the movement of the deflectable structure on the basis of the moving into the defined position or on the basis of the moving out of the defined position and to determine an atmospheric property in the housing on the basis of the movement characteristic.

A MEMS photoacoustic gas sensor includes a first membrane and a second membrane opposing the first membrane and spaced apart from the first membrane by a sensing volume. The MEMS photoacoustic gas sensor includes an electromagnetic source and communication with the sensing volume to deflect the first membrane and the second membrane.

Apparatus and methods for measuring infrared absorption of a sample that includes delivering a pulse of infrared radiation to a region of the sample, delivering pulses of radiation of a shorter wavelength than infrared radiation to a sub-region within the region, and using one or more properties of the induced photoacoustic signals to create a signal indicative of infrared absorption of the sub-region of the sample.

A MEMS sensor includes a sensor package and a membrane arranged in the sensor package, wherein a first partial volume of the sensor package adjoins a first main side of the membrane and a second partial volume of the sensor package adjoins a second main side of the membrane, wherein the second main side is arranged opposite the first main side. The MEMS sensor includes a first opening in the sensor package, said first opening connecting the first partial volume to an external environment of the sensor package in an acoustically transparent fashion. The MEMS sensor includes a second opening in the sensor package, said second opening connecting the second partial volume to the external environment of the sensor package in an acoustically transparent fashion.

A MEMS photoacoustic gas sensor includes a first membrane and a second membrane opposing the first membrane and spaced apart from the first membrane by a sensing volume. The MEMS photoacoustic gas sensor includes an electromagnetic source and communication with the sensing volume to deflect the first membrane and the second membrane.

A fluid sensor includes a housing structure forming a cavity for an IR emitter for emitting an IR radiation in the cavity, wherein the IR radiation has a center wavelength for providing an interaction of the IR radiation with the target fluid resulting in a temperature change in the cavity or in the housing structure, which effects a mechanical pulse in the housing structure, and an inertial detection sensor mechanically coupled to the housing structure for sensing the mechanical pulse in the housing structure.

A photoacoustic measurement setup having an infrared radiator that is suitable for radiating broadband light with periodically modulated energy/intensity. The infrared radiator is configured to change an excitation spectra of a radiated broadband light, and a gas volume is heated by the radiated broadband light to generate an acoustic wave within the gas volume. The photoacoustic measurement setup also includes an acoustic sensor, which is suitable for measuring the acoustic wave generated in the gas volume.

A method of detecting a species, strain or type of bacteria includes mixing a labeled bacteriophage including a label that is detectible via a detection system with a bacterial culture including the species, strain or type of bacteria to which the labeled bacteriophage selectively binds and using the detection system to detect the labeled bacteriophage bound to the species, strain or type of bacteria.

This disclosure presents a process to determine characteristics of a subterranean formation proximate a borehole. Borehole material can be typically pumped from the borehole, though borehole material can be used within the borehole as well. Extracted material of interest can be collected from the borehole material and prepared for analyzation. Typically, the preparation can utilize various processes, for example, separation, filtering, moisture removal, pressure control, cleaning, and other preparation processes. The prepared extracted material can be placed in a photoacoustic device where measurements can be taken, such as a photoacoustic imager or a photoacoustic spectroscopy device. A photoacoustic analyzer can generate results utilizing the measurements, where the results of the extracted material can include one or more of fracture parameters, fracture plane parameters, permeability parameters, porosity parameters, and composition parameters. The results can be communicated to other systems and processes to be used as inputs.

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.