A sensor device includes a substrate having a front surface and an opposing back surface. The back surface defines an indented region having an indented surface. The substrate defines a bottom port extending between the front surface and the indented surface. The sensor further includes a microelectromechanical systems (MEMS) transducer mounted on the front surface of the substrate over the bottom port. The sensor also includes a filtering material disposed on the indented surface and covering the bottom port. The filtering material provides resistance to ingression of solid particles or liquids into the sensor device. The filtering material is configured to provide high acoustic permittivity and have low impact on a signal-to-noise ratio of the sensor device.

A pressure sensing device is configured for measuring water pressure in a soil medium, and includes a sensor housing and a pressure sensor. The sensor housing is adapted with a sensor cavity delimited by an enveloping surface. The sensor housing is provided with a selective passage for water between an outer surface of the sensor housing and the sensor cavity. The pressure sensor is arranged within the sensor cavity for measurement of a water pressure within the sensor cavity. The pressure sensing device includes an antimicrobial substance for preventing microbial gas production in the sensor cavity.

A pressure introducing chamber is provided with a baffle plate which is positioned with one surface thereof facing in a direction orthogonal to a direction of travel of a measured medium introduced through a pressure introducing hole into the pressure introducing chamber. A first distance between a pressure receiving surface of a sensor diaphragm and an inner surface of the pressure introducing chamber facing the pressure receiving surface and a second distance between the pressure receiving surface of the sensor diaphragm and the other surface of the baffle plate facing the pressure receiving surface are both smaller than a mean free path of the measured medium in the entire region of the pressure receiving surface of the sensor diaphragm.

A differential pressure monitoring apparatus includes a case having a continuous sidewall including a first end closed a by first end cap, and a second end closed by a second end cap. A differential pressure monitoring unit mounted in the case includes a differential pressure sensor in communication with the external environment, a temperature and humidity sensor in communication with an internal atmosphere inside the case, a data processor operatively connected to the sensors, data storage, an information display viewable through the case, a non-gas permeable membrane tube in connection with the differential pressure sensor and an internal environment and a harsh and/or corrosive gas filter in connection to the differential pressure sensor.

A sensor device includes a substrate having a front surface and an opposing back surface. The back surface defines an indented region having an indented surface. The substrate defines a bottom port extending between the front surface and the indented surface. The sensor further includes a microelectromechanical systems (MEMS) transducer mounted on the front surface of the substrate over the bottom port. The sensor also includes a filtering material disposed on the indented surface and covering the bottom port. The filtering material provides resistance to ingression of solid particles or liquids into the sensor device. The filtering material is configured to provide high acoustic permittivity and have low impact on a signal-to-noise ratio of the sensor device.

An air sensor system including a pressure or airflow sensor, a filter housing that defines an air flow path to the air pressure sensor, and a filter in the air flow path. The filter includes a micro filter and a hydrophobic membrane. The hydrophobic membrane is downstream of the micro filter in the air flow path to the pressure or airflow sensor.

Aspects of the subject technology relate to an apparatus having a housing including a port exposed to an environment. A pressure sensor is disposed within the housing to measure a pressure of the environment. A medium partially fills a sensor cavity or is coated over the pressure sensor, and a cap including multiple openings is disposed over the pressure sensor. The openings of the cap are arranged to be offset from the port.

A sensor device including a case main body, a sensor portion provided in the case main body, and an exterior member which is provided on a circumferential portion of the case main body, and has at least one first opening at a positioned shifted in a predetermined direction from an opposing direction of the sensor portion, in which a flow route where fluid is flowable into the sensor portion through at least the first opening is formed between the case main body and the exterior member.

According to the present disclosure, at least two fluid inlet/outlet pipes, each of which is provided with a filter, are installed outside a structure to be bent and an end of each of the fluid inlet/outlet pipes is connected to a pressure sensor provided on the structure. Thus, since a fluid in the state in which low-frequency and high-frequency components of the disturbances generated outside the structure are removed therefrom acts on the pressure sensor, the underwater pressure sensing apparatus is capable of measuring fluid pressure in a stable state.

The disclosed technology includes a transducer assembly having a first transducer element. The transducer assembly includes a first filter element adjacent to least of portion of the first transducer element such that a first cavity is defined between the first filter element and the first transducer element. The first filter element includes a plurality of machined passageways in communication with the first cavity. The transducer assembly also includes an inlet passage having a first end in communication with a first external portion of the transducer assembly and a second end in communication with the plurality of machined passageways.