A system and method for measuring a flow of saturated steam can include a temperature sensor that measures process temperature, and one or more pressure sensors that measure pressure including differential pressure and static pressure. A flow of saturated steam can be calculated from two sets of measurements, one measurement using the differential pressure and the static pressure and a second measurement using the differential pressure and the process temperature. Redundant flow measurements can be provided with respect to the flow of saturated steam in case of failure of the temperature sensor or the pressure sensors. In addition, a deviation between the flow of the saturated steam as calculated from the process temperature and the differential pressure compared to a flow of saturated steam as calculated from the differential pressure and the static pressure can provide an indication of degradation of the temperature sensor or the pressure sensors.

A mass flow control system can be self verified for its accuracy when controlling a flow to a process. The system comprises: a control valve for controlling the flow of fluid through the system as a function of a control signal; a controller for generating the control signal as a function of measured flow of fluid through the system and a targeted flow set point; a pressure sensor for measuring the controlling fluid pressure for use in measuring and verifying the flow rate; and a source of fluid for providing a known volume of fluid for use in verifying the system accuracy anytime between steps of the flow control process.

Provided is a technique capable of more accurately measuring and outputting a flow rate according to an intended purpose, in a flow rate measurement device. A flow rate measurement device (1) for detecting a flow rate of measurement target fluid flowing through a main flow path (2) includes: a heater (113) configured to heat measurement target fluid; a plurality of temperature detectors (111, 112) that are arranged with the heater interposed in between in a flow direction of the measurement target fluid, and are configured to detect a temperature of the measurement target fluid; and a converter (133) configured to convert a difference in outputs of the plurality of temperature detectors into a heat flow rate or a heat quantity of measurement target fluid flowing through the main flow path.

An airflow velocity measuring apparatus that includes a fixed-temperature heat generating device. The fixed-temperature heat generating device includes a power supply, a positive-temperature-coefficient thermistor element, a switching element, a comparator element, a first negative-temperature-coefficient thermistor element, a second negative-temperature-coefficient thermistor element, and plural resistor elements. The positive-temperature-coefficient thermistor element is disposed at a measuring point at which the velocity of airflow is measured. The switching element is repeatedly turned ON and OFF so as to cause the positive-temperature-coefficient thermistor element to generate heat at a preset temperature, thereby applying a pulse voltage from the power supply to the positive-temperature-coefficient thermistor element. The airflow velocity measuring apparatus measures the velocity of airflow at the measuring point based on the waveform of this pulse voltage. Adding of a second switch makes it possible to correct measurement errors caused by a rise or a fall in the temperature of subject airflow.

A diagnostics system comprising a controller for controlling operations of a mass flow controller. The controller is communicable coupled to at least one sensor and to a valve and tuned to control the valve based on a predetermined set point value and communication from the at least one sensor. The controller determines at least one predetermined value associated with a reverse flow of a fluid and either cause the controller to enter a hard fault or a safe state. The predetermined value of the flow is either a percentage of total flow or a percentage of total flow over a time period. The controller can log the date, time, and a device identifier in response to determining the at least one predetermined value. In addition, the diagnostics system can include a centralized controller configured to receive diagnostics data from a plurality of controllers and control operation of the controllers.

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 device for measuring the speed or flow of a gas at a temperature different from an ambient temperature is provided, which includes: a first platform suspended by first arms above a support designed to be kept at an ambient temperature, the first arms comprising thermoelectric strips designed to supply a first voltage based on the difference between the temperatures of the first platform and the support; and a processing unit designed to supply the speed or flow measurement on the basis of the first voltage, the gas temperature and the ambient temperature.

A communication system includes a flow measuring device and a control device. The flow measuring device includes a flow sensor that generates a flow rate signal which is a signal in accordance with a flow rate of intake air drawn into an internal-combustion engine. The flow measuring device transmits the flow rate signal. The control device receives the flow rate signal and performs at least one of injection control of fuel to be supplied to the engine and ignition control at each cylinder of the engine based on the received flow rate signal. The flow measuring device includes a measurement-side transmitting part that transmits various signals by wireless communication, and transmits the flow rate signal by the measurement-side transmitting part. The control device includes a control-side receiving part that receives the various signals by the wireless communication, and receives the flow rate signal by the control-side receiving part.

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.

An imaging system includes a sight tube extending along a longitudinal axis of the imaging system and configured to extend through an access port. The sight tube includes a wall extending about the longitudinal axis and defining a cavity. The imaging system also includes a plurality of cooling channels extending through the sight tube. The plurality of cooling channels are configured to direct cooling fluid through the sight tube for cooling the imaging system. The plurality of cooling channels are formed in the sight tube such that at least one cooling channel of the plurality of cooling channels extends in a direction oblique to the longitudinal axis.