The disclosure relates to a sensor apparatus and a method for measuring the flow rate of a shielding gas in a welding apparatus. The sensor apparatus comprises at least one inlet and at least one outlet in fluid connection with one or more bypass channels and with one or more sensor channels, and at least one input hose and one output hose. The apparatus also comprises one or more thermal mass flow sensors connected to the one or more sensor channels, and a control unit configured to retrieve sensor responses from the one or more thermal mass flow sensors and to determine the flow rate of the shielding gas through the sensor apparatus based on the retrieved sensor response and calibration data, wherein the calibration data comprises one or more characteristic curves comprising gas flow values and sensor response values. The control unit is configured to retrieve from a memory unit: the composition of the shielding gas; the number of active thermodynamic degrees of freedom which the molecules of each gas component in the shielding gas possess at the retrieved shielding gas temperature; a characteristic curve for each gas component separately, which consists of sensor response data as a function of gas flow rate, measured in a calibration experiment conducted with a pure gas consisting only of that gas component. The control unit is configured to calculate a new, mixture-specific characteristic curve for the gas mixture as a weighted average of the pure-gas characteristic curves, wherein the weight assigned to each value on a pure-gas characteristic curve is a product of the concentration percentage of that gas component in the shielding gas mixture and the number of active thermodynamic degrees of freedom which the molecules of that gas component possess at the retrieved shielding gas temperature; and to use the mixture-specific characteristic curve as the characteristic curve for the shielding gas mixture by retrieving from this characteristic curve the calibration gas flow rate which corresponds most closely to the retrieved new sensor response; and to identify this flow rate as the current flow rate of the shielding gas through the sensor apparatus. The sensor apparatus also comprises a display unit configured to display the determined flow rate of the shielding gas to a user and/or a memory unit for storing the determined flow rate of the shielding gas.

A physical quantity measuring device detects a physical quantity of gas flowing in a flow passage. The physical quantity measuring device includes a sensor element that outputs a detection signal according to the physical quantity, a case that is provided to the flow passage and houses the sensor element, and a protrusion that protrudes from a passage wall surface facing the flow passage. The case includes a measurement chamber that houses the sensor element and an inflow port that is configured to cause a part of gas flowing in the flow passage to flow into the measurement chamber therethrough. The protrusion is configured to guide gas flowing along the passage wall surface toward the inflow port.

An air flow rate measuring device for a vehicle measures an air flow rate based on an output value of a sensing unit disposed under an environment in which an air flows. The air flow rate measuring device includes a processor programmed to calculate a standard deviation from sampling data in the output value for at least one cycle of a pulsation waveform of the air, calculate a kurtosis of the pulsation waveform from the output value, estimate the pulsation error that is correlated with the standard deviation and the kurtosis, and correct the air flow rate to mitigate the pulsation error by using the pulsation error.

Techniques for the design and operation of an efficient battery-powered meter are described herein. A metrology unit of the meter may be at least partially located in the gas flow of a pipe, and measures gas flow rate data according to a static flow sensor. The metrology unit calculates raw gas-volume data using at least the flow rate data as input. The metrology unit measures gas temperature to produce gas temperature data, and adjusts the raw gas-volume data, based at least in part on the gas temperature data, to produce corrected gas-volume data. The metrology unit accumulates the corrected gas-volume data over multiple minutes, hours or even days, and then sends the accumulated corrected gas-volume data to an index unit of the meter. By accumulating the data over time, fewer data transmissions are required. The index unit may send the accumulated the accumulated corrected gas-volume data to a utility server.

In a capillary heating type thermal type mass flow meter comprising a sensor configured to detect temperature and pressure of a fluid and a correction means configured to correct a mass flow rate based on said temperature and said pressure, change rates of the mass flow rate of the fluid with respect to temperature and pressure have been previously acquired, and the mass flow rate is corrected based on said temperature and said pressure as well as these change rates. Thereby, the mass flow rate can be measured accurately and simply even when the temperature and/or pressure of the fluid, whose mass flow rate is to be measured, change.

In an apparatus and method for measuring air flow in a duct, e.g. in a ventilation duct, the apparatus includes a sensor fittable into connection with the duct at a certain distance from an interference source, the sensor including an ultrasound transmitter and at least two ultrasound receivers, and a control unit to which the ultrasound transmitter and ultrasound receivers are connectable. The control unit is adapted to measure the phase difference of the ultrasound signal received at the same moment in time by at least two ultrasound receivers fitted into connection with the duct and, based on the measured phase difference, to determine the flow velocity and/or flow direction of the air. The control unit is adapted to compensate the determined flow velocity and/or flow direction of the air with a coefficient that is formed on the basis of the diameter of the duct, the type of interference source and the distance between the sensor and the interference source.

Systems and methods for finding and solving problems with wet gas venturi meters in one or more gas well sites include one or more gas well sites configured to supply gas to a gas plant, each gas well site comprising a gas well connected to a piping, one or more valves installed on the piping, one or more pressure sensors, one or more temperature sensors, one or more venturi meters configured to measure a differential pressure of the gas in the piping. The system is configured to directly use the field instrument data (P, T, dP) and use dimensions of venturi meter and the fluid properties values of gas wells, and calculate the gas flow and gas condensate of the wells.

The embodiments of the present disclosure provide a method and system for compensating ultrasonic metering based on a smart gas Internet of Things system, comprising: determining a first preset condition based on a gas pipeline feature obtained from an external database, wherein the first preset condition refers to a judgment condition for evaluating whether a flow compensation is required; obtaining a gas transportation feature and an environmental feature based on at least one sensor; determining a compensation scheme based on the gas transportation feature, the environmental feature, and the first preset condition, wherein the compensation scheme includes at least one of a flow rate compensation coefficient, a flow compensation parameter, a temperature compensation coefficient, or a pressure compensation coefficient; sending the compensation scheme to an ultrasonic metering device, and controlling the ultrasonic metering device to determine updated flow metering data according to the compensation scheme.

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 thermopile sensor includes a thermopile. The thermopile is formed by connecting thermocouples, in series on an insulating film, in which a first PolySi interconnect and a metal interconnect including a metal portion in at least a part thereof are connected, each of the thermocouples connected in series is arranged side by side with a predetermined gap, the metal interconnect is arranged to overlap the first PolySi interconnect in each of the thermocouples, at a connection portion between a thermocouple and an adjacent thermocouple, the metal interconnect crosses the gap between the first PolySi interconnects, and a first width of a portion of the gap where the metal interconnect crosses the gap between the first PolySi interconnects is greater than a second width of a remaining portion of the gap between the first PolySi interconnects.