A multi-chamber rate-of-change flow meter system and methods for operating the same are disclosed. The multi-chamber rate-of-change flow meter system includes a collection of N chambers, means for drawing a gas into or out of the collection of N chambers, N pressure sensors corresponding one of the N chambers, and means for redistributing the gas among the chambers. A measurement module is coupled to the pressure sensors to obtain a rate of change of pressure in each of the chambers due to the redistribution of the gas and calculate a flow rate of the gas flowing into or out of the collection of N chambers based upon the rate of change of pressure in each of the chambers.

A temperature sensor differs from a relative humidity sensor in responsiveness when the temperature of air changes. An absolute humidity acquisition unit acquires absolute humidity of air from outputs from the temperature sensor and the relative humidity sensor. A delay adjustment unit is to delay an output from one of the temperature sensor and the relative humidity sensor, which is a high response sensor having a higher responsiveness, and to reconcile change-behaviors of the output from the temperature sensor and the output from the relative humidity sensor in response to a temperature change in air. The absolute humidity acquisition unit acquires the absolute humidity based on the output from the other of the temperature sensor and the relative humidity sensor, which is a low response sensor having a lower responsiveness, and the sensor signal, which is from the high response sensor and delayed in the delay adjustment unit.

Techniques detect a low gas-pressure condition within a region without the use of pressure sensors. In an example, gas usage at a service site is disaggregated to show use by individual appliances. A flowrate of gas at an appliance (e.g., a gas hot water tank) having a generally fixed-rate of gas-consumption is determined. Based at least in part on the flowrate of gas at the appliance, and an historical gas flowrate at that appliance, it is determined if gas pressure at the service site is lower than expected. In an example, failure of the appliance to use its typical fixed-flowrate may indicate low gas pressure at the service site. Information is obtained from a second gas meter at a second service site. Based on the gas pressure at the first and second service sites being lower than expected, a low gas pressure situation may exist in a regional area.

The present disclosure provides a metering and correcting method and system for an ultrasonic gas meter based on smart gas Internet of Things (IoT). The metering and correcting method is implemented on a smart gas device management platform of the metering and correcting system and includes: in response to receiving a co-correction request from the ultrasonic gas meter, obtaining ultrasonic data and gas medium data; determining a target signal stability value of the ultrasonic gas meter based on the ultrasonic data and the gas medium data; in response to the target signal stability value not meeting a second preset condition, determining a co-correction strategy and sending the co-correction strategy to the ultrasonic gas meter; and evaluating a correction accuracy of the ultrasonic gas meter for performing a correction process based on the co-correction strategy.

A method for calibrating a gas flow metrology system for a substrate processing system includes a) measuring temperature using a first temperature sensor and a reference temperature sensor over a predetermined temperature range and determining a first transfer function; b) measuring pressure using a first pressure sensor and a reference pressure sensor over a predetermined pressure range using a first calibration gas and determining a second transfer function; c) performing a first plurality of flow rate measurements in a predetermined flow rate range with a first metrology system and a reference metrology system, wherein the first metrology system and the reference metrology system use a first orifice size and the first calibration gas; and d) scaling temperature and pressure using the first transfer function and the second transfer function, respectively, and determining a corresponding transfer function for the first calibration gas based on the first plurality of flow rate measurements.

A housing defines a bypass passage and a sub-bypass passage therein. A bypass passage is configured to draw a part of an air flowing through a duct. The sub-bypass passage branches off the bypass passage and is configured to draw a part of air flowing through the bypass passage. A flow rate sensor is arranged in the sub-bypass passage and configured to generate an electric signal according to a flow rate of air in the duct by performing heat transfer with air passing through the sub-bypass passage. A physical quantity sensor is configured to measure a physical quantity of air in the duct. A sensor assembly is integrally formed with the flow rate sensor, the physical quantity sensor, and a circuit module. The circuit module includes a substrate that is configured to process signals from the flow rate sensor and the physical quantity sensor.

A sensor for sensing a flow rate of a fluid comprises an upstream resistive element having a first resistance that changes with temperature, a downstream resistive element having a second resistance that changes with temperature, at least one tail resistor configured to determine thermal conductivity of the fluid, at least one pressure sensor configured to determine a differential pressure in the flow direction of the fluid, and circuitry configured to use the differential pressure with the thermal conductivity to determine a kinematic viscosity of the fluid, and compensate an output of the bridge circuit. The downstream resistive element is situated downstream of the upstream resistive element in the flow direction of the fluid, and the upstream resistive element and the downstream resistive element are operatively connected in a bridge circuit.

A method may include obtaining first pressure data regarding a first pressure sensor upstream from a restricted orifice and second pressure data regarding a second pressure sensor downstream from the restricted orifice. The method may further include obtaining temperature data regarding a temperature sensor coupled to the restricted orifice. The method may further include obtaining various gas parameters regarding a predetermined gas flowing through the restricted orifice and various orifice parameters regarding the restricted orifice. The method may further include determining a first gas flow rate of the predetermined gas based on a gas flow model, the first pressure data, the second pressure data, the temperature data, the gas parameters, and the orifice parameters.

An air-mass measuring apparatus for a vehicle, that has a support element, an air-mass sensor for providing air-mass data, the air-mass sensor being disposed on the support element, at least one further sensor for providing further sensor data, the at least one further sensor being disposed on the support element, and an evaluation circuit having a first input interface to receive the air-mass data, at least one second input interface to receive the further sensor data and having an output interface, the evaluation circuit being disposed on the support element and being designed to provide the air-mass data and the further sensor data as bundled sensor data via the output interface.

Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector. The thermal flow meter includes a bypass passage through which a measurement target gas flowing through a main passage flows, and a circuit package which includes a measurement circuit for measuring a flow rate of the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas. The circuit package includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion molded by the resin. The temperature detecting portion is provided in the leading end portion of the protrusion, and at least the leading end portion of the protrusion protrudes to the outside from a housing.