The invention relates to an optical pressure sensor, such as a microphone, being constituted by two membranes, but where the sound does not arrive perpendicular to the membrane, but comes in from the side. The membranes may be parallel as in a Fabry-Perot or slightly skew as in an Air-wedge shearing interferometer. The pressure sensor uses interferometric readout, and consists of two membranes with essentially equal characteristics, where at least one of the membranes is partially transmitting and partially reflective and the other membrane is at least partially reflective, the membranes being separated by a cavity defined by a spacer part, where the distance between the membranes is variable to provide a shift sensitive Fabry-Perot resonator, and where the two membranes have a common back volume being sealed or essentially sealed in the frequency one wish to measure, and where a pressure increase results in that the distance between the membranes move in opposite directions.

This disclosure provides example methods, devices, and systems for a sensor having a Helmholtz resonator. In one embodiment, a system may comprise a sensing element; a header coupled to the sensing element; a housing coupled to the header; an adaptor coupled to the housing; a screen disposed in an opening of the housing, wherein a first cavity is disposed between the screen and the sensing element and a second cavity is disposed between the adaptor and the sensing element, and the screen in combination with the first cavity and the second cavity form a Helmholtz resonator.

This disclosure provides example methods, devices, and systems for a sensor having a Helmholtz resonator. In one embodiment, a system may comprise a sensing element; a header coupled to the sensing element; a housing coupled to the header; an adaptor coupled to the housing; a screen disposed in an opening of the housing, wherein a first cavity is disposed between the screen and the sensing element and a second cavity is disposed between the adaptor and the sensing element, and the screen in combination with the first cavity and the second cavity form a Helmholtz resonator.

The invention relates to a segment of pipe-in-pipe pipeline comprising an annulus under reduced pressure sealed and delimited by a metallic internal pipe inserted into a metallic external pipe and provided with a measurement system to determine in a non-intrusive manner the state of the annulus, the measurement system being composed of a first internal emitter/receiver assembly placed inside the annulus and cooperating with means to measure a first physical quantity such as pressure, hygrometry or temperature inside the reduced pressure annulus and a second external emitter/receiver assembly arranged to the exterior of the segment and facing said first assembly.

Transducer assemblies may include a sensor and a housing including a pass-through portion comprising at least one aperture in a portion of the housing extending along a longitudinal axis of the housing and the sensor. Methods of forming transducer assemblies may include welding a first housing section of the transducer assembly to a second housing portion of the transducer assembly and forming at least one aperture in the first housing section extending along a longitudinal axis of the transducer assembly, along a chamber for holding a sensor, and through the weld.

Transducer assemblies may include a sensor and a housing including a pass-through portion comprising at least one aperture in a portion of the housing extending along a longitudinal axis of the housing and the sensor. Methods of forming transducer assemblies may include welding a first housing section of the transducer assembly to a second housing portion of the transducer assembly and forming at least one aperture in the first housing section extending along a longitudinal axis of the transducer assembly, along a chamber for holding a sensor, and through the weld.

A system to determine a temperature corrected pressure of a medium in a pressure transducer is disclosed. The system comprises a first circuitry to obtain a first value related to a vibration frequency of the vibration of a pressure sensitive vibration member; a second circuity to obtain a second value related to a vibration amplitude of the vibration of the vibration member; and a third circuity to use the first value and the second value to determine the temperature corrected pressure of the medium based on a predetermined relationship between the vibration frequency and the vibration amplitude.

A system to determine a temperature corrected pressure of a medium in a pressure transducer is disclosed. The system comprises a first circuitry to obtain a first value related to a vibration frequency of the vibration of a pressure sensitive vibration member; a second circuity to obtain a second value related to a vibration amplitude of the vibration of the vibration member; and a third circuity to use the first value and the second value to determine the temperature corrected pressure of the medium based on a predetermined relationship between the vibration frequency and the vibration amplitude.

Transducer assemblies may include a sensor and a housing including a pass-through portion comprising at least one aperture in a portion of the housing extending along a longitudinal axis of the housing and the sensor. Methods of forming transducer assemblies may include welding a first housing section of the transducer assembly to a second housing portion of the transducer assembly and forming at least one aperture in the first housing section extending along a longitudinal axis of the transducer assembly, along a chamber for holding a sensor, and through the weld.

Transducer assemblies may include a sensor and a housing including a pass-through portion comprising at least one aperture in a portion of the housing extending along a longitudinal axis of the housing and the sensor. Methods of forming transducer assemblies may include welding a first housing section of the transducer assembly to a second housing portion of the transducer assembly and forming at least one aperture in the first housing section extending along a longitudinal axis of the transducer assembly, along a chamber for holding a sensor, and through the weld.