A throughflow measurement system for measuring a fluid throughflow through a pipe comprises a first measurement arrangement that comprises at least two ultrasonic transducers and that is configured to determine a value for the fluid throughflow through the pipe on the basis of transit times of ultrasonic signals transmitted and received with and against the flow; a second measurement arrangement that comprises a plurality of hot-wire sensors that are arranged distributed over the cross-section of the pipe and that are each configured to determine a local flow value; and an evaluation device that is in signal connection with the first measurement arrangement and with the second measurement arrangement and that is configured to determine a flow profile on the basis of the local flow values determined by the hot-wire sensors and to modify the value for the fluid throughflow, which is determined by the first measurement arrangement, on the basis of the determined flow profile.

A throughflow measurement system for measuring a fluid throughflow through a pipe comprises a first measurement arrangement that comprises at least two ultrasonic transducers and that is configured to determine a value for the fluid throughflow through the pipe on the basis of transit times of ultrasonic signals transmitted and received with and against the flow; a second measurement arrangement that comprises a plurality of hot-wire sensors that are arranged distributed over the cross-section of the pipe and that are each configured to determine a local flow value; and an evaluation device that is in signal connection with the first measurement arrangement and with the second measurement arrangement and that is configured to determine a flow profile on the basis of the local flow values determined by the hot-wire sensors and to modify the value for the fluid throughflow, which is determined by the first measurement arrangement, on the basis of the determined flow profile.

The present invention provides a thermal flow meter that includes a sensor flow path along which flows a fluid being measured, an upstream-side electrical resistance element provided on the sensor flow path, a downstream-side electrical resistance element provided downstream of the upstream-side electrical resistance element, a sensor output generator that, based on respective voltages that are output in accordance with changes in the upstream-side and downstream-side electrical resistance elements, generates a sensor output in accordance with the flow rate of the fluid being measured, a slope effect estimator that, based on at least a Prandtl number of the fluid being measured, estimates a slope effect that is generated in the sensor output in accordance with an attitude of the sensor flow path, and a flow rate calculator that corrects the slope effect from the sensor output, and calculates the flow rate of the fluid being measured.

The present invention provides a thermal flow meter that includes a sensor flow path along which flows a fluid being measured, an upstream-side electrical resistance element provided on the sensor flow path, a downstream-side electrical resistance element provided downstream of the upstream-side electrical resistance element, a sensor output generator that, based on respective voltages that are output in accordance with changes in the upstream-side and downstream-side electrical resistance elements, generates a sensor output in accordance with the flow rate of the fluid being measured, a slope effect estimator that, based on at least a Prandtl number of the fluid being measured, estimates a slope effect that is generated in the sensor output in accordance with an attitude of the sensor flow path, and a flow rate calculator that corrects the slope effect from the sensor output, and calculates the flow rate of the fluid being measured.

Aspects of the subject technology relate to electronic devices having speakers and airflow sensors for the speakers. In one or more implementations, the airflow sensor may be formed, in part, by a mesh structure that spans a port in a housing of the electronic device. In one or more implementations, the airflow sensor may be formed, in part, by an exposed portion of a conductive trace of the speaker.

A thermoresistive gas sensor includes two identical, flat meshes that consist of a semiconductor material with a predetermined type of conductivity and that are interconnected in sections of an electric measuring bridge that are diametrically opposite one another, wherein each mesh of the two identical, flat meshes has mesh webs that extend parallel, adjacent to one another and that are connected electrically in parallel at the ends, where the mesh webs of the two meshes extend alternately adjacent to one another in a shared mesh plane horizontally across a window opening in a carrier plate.

A thermoresistive gas sensor includes two identical, flat meshes that consist of a semiconductor material with a predetermined type of conductivity and that are interconnected in sections of an electric measuring bridge that are diametrically opposite one another, wherein each mesh of the two identical, flat meshes has mesh webs that extend parallel, adjacent to one another and that are connected electrically in parallel at the ends, where the mesh webs of the two meshes extend alternately adjacent to one another in a shared mesh plane horizontally across a window opening in a carrier plate.

A method is provided for measuring different flow properties of a fluid. The method includes (a) providing a nanowire, the resistance of the nanowire varying based on temperature changes of the nanowire that reflect values of the different flow properties of the fluid when the nanowire is operated in different modes of operation respectively, such that the nanowire measures different flow properties when operated in different modes of operation respectively, and (b) alternating the nanowire between different modes of operation, measuring different flow properties of the fluid during the different modes of operation, respectively, and using the measurements of one of the flow properties to correct the measurements of another flow property. Other applications are also described.

A method is provided for measuring different flow properties of a fluid. The method includes (a) providing a nanowire, the resistance of the nanowire varying based on temperature changes of the nanowire that reflect values of the different flow properties of the fluid when the nanowire is operated in different modes of operation respectively, such that the nanowire measures different flow properties when operated in different modes of operation respectively, and (b) alternating the nanowire between different modes of operation, measuring different flow properties of the fluid during the different modes of operation, respectively, and using the measurements of one of the flow properties to correct the measurements of another flow property. Other applications are also described.

A sensor support portion supports a physical quantity sensor. A flow path housing portion forms a measurement flow path, which accommodates a support tip end portion of the sensor support portion. The sensor support portion includes a support front surface, which includes a front fixed portion away from the support tip end portion and fixed to an inner surface of the flow path housing portion. The physical quantity sensor includes a sensor exposure surface exposed from the support front surface. A separation distance between an end portion of the front fixed portion and an end portion of the sensor exposure surface is smaller than a separation distance between the end portion of the sensor exposure surface and the support tip end portion.