A gases humidification system includes a measuring chamber and a mixing chamber. The mixing chamber has one or more mixing elements that improve a mixing of gases before reaching the measuring chamber. Ultrasonic sensing is used to measure gases properties or characteristics within the measuring chamber. A baffle or a vane may be used to control and direct the gases flow through the mixing chamber as the gases flow moves into the measuring chamber.

An airflow calibrator 10 may generally comprise an inlet 15 in fluid communication with an outlet 20 to define a flow path 30 of a fluid through the airflow calibrator 10; a face seal valve 40 in fluid communication with the inlet 15; a removable flow cell 50 in fluid communication with the face seal valve 40; a variable restrictor valve 60 in fluid communication with the removable flow cell 50; and an optical sensor array 70 to determine the airflow, i.e., flow rate, of an air sampling pump in fluid communication with the airflow calibrator. Methods of using the airflow calibrator are also described.

A self-diagnosis method of a flow rate control device includes: a step (a) for measuring a pressure drop characteristic after a pressure control valve (6) has been changed to a closed state from a state where a fluid flows from the upstream side of the pressure control valve with the opening of a flow rate control valve (8) is larger than a restriction part; a step (b) for measuring the pressure drop characteristic after the pressure control valve has been changed to the closed state from a state where the fluid flows from the upstream side of the flow rate control valve to the downstream side with the opening of the flow rate control valve is smaller than the restriction part; a step (c) for determining whether there is an abnormality by comparing the pressure drop characteristic measured in step (a) with a corresponding reference pressure drop characteristic; a step (d) for determining whether there is an abnormality by comparing the pressure drop characteristic measured in step (b) with a corresponding reference pressure drop characteristic; and a step (e) for determining that there is an abnormality in the flow rate control valve when it is determined that there is an abnormality only in the step (d).

A fluid sensing apparatus includes a fluid sensor configured to detect a temperature distribution on a detection surface caused by heating, and output a signal value corresponding to a flow of a fluid; a falling time counting unit configured to count a falling time of the signal value after stopping the heating; and a failure determining unit configured to perform failure determination based on the falling time.

A flow rate control system including a flow rate controller controlling a flow rate of a fluid supplied to a controlled object to keep a desired flow rate set value is provided, and includes a flow rate sensor, a pressure sensor measuring a pressure of a primary side of the flow rate controller, a PI calibration value determination unit determining a PI calibration value based on at least a physical property coefficient according to a physical property value of the fluid, a correction unit correcting an estimated flow rate, based on the PI calibration value and a measured value, and a drive control circuit adjusting an opening of a valve supplying the fluid to the controlled object based on the estimated value and controlling the flow rate of the fluid. A flow rate is accurately calculated regardless of types of a fluid in the pressure insensitive type flow rate controller.

The present disclosure discloses a risk prevention method based on energy of natural gas in a full cycle, including: obtaining loss data of natural gas based on metering equipment, wherein the loss data of the natural gas includes metering data of the natural gas consumed in a measured area during a plurality of time periods; obtaining output data of natural gas, wherein the output data of the natural gas includes metering data of the natural gas transmitted by a gas supplier in the measured area during the plurality of time periods; based on the processing of loss data of natural gas and output data of natural gas, determining whether natural gas transmission is abnormal.

Mass flow controllers and methods for controlling mass flow controllers are disclosed. A method includes providing a gas through a thermal mass flow sensor of the mass flow controller and processing a sensor signal from the thermal mass flow sensor to produce a flow signal. A total nonlinearity characteristic function is determined based on nonlinearity effects on the flow signal and includes a first and second nonlinearity component function based on a first and second source of nonlinearity respectively. The total nonlinearity characteristic function is calibrated, and the first nonlinearity component function is adjusted responsive to changes in the first source of nonlinearity, after which the total nonlinearity characteristic function is updated. The flow signal is corrected to produce a corrected flow signal using the total nonlinearity characteristic function. A valve of the mass flow controller is controlled using the corrected flow signal and a setpoint signal.

A system includes a flow tube configured to receive a flow measured by an ultrasonic flow measurement, wherein a center region of the flow tube is configured to have a drop in pressure. The system also includes a heat source/hot wire and temperature sensors configured to enable a flow measured by a thermal massflow measurement. In the system, a controller is configured to compare the flow measured by the ultrasonic flow measurement to the flow measured by the thermal massflow measurement. The controller determines a ratio of the flow measured by an ultrasonic flow measurement to the flow measured on by the flow measurement based on thermal massflow. The controller also calculates a density, a thermal conductivity and an energy and/or gas content of the gas.

Embodiments of a portable verification system can move from one in-field gas flow meter location to another and temporarily connect downstream of a main pipeline's meter run or station. A control valve of the portable verification system allows volume measurement at different flow velocities to be verified. In some embodiments, the portable verification system is connected to the meter run and the main pipeline by an adjustable pipeline section. This section can extend horizontally and vertically, as well as swivel to provide versatility when connecting in the field. Adaptor fittings having one flange sized for and fitted to the inlet and outlet ends of the portable verification system and another flange sized for the meter run or main pipeline connection provide additional versatility. Downtime is limited to the time required to complete a circuit between the meter run, portable verification system, and main pipeline.

A flow controller for filling evacuated canisters can be operated at different reference pressures to produce substantially the same flow rates to facilitate inertness testing of the flow controller through demonstrated recovery of trace level chemicals in a challenge standard prior to using the flow controllers to collect air samples for measurement of VOCs during time weighted sampling events. The flow controller can include a first chamber and a second chamber divided by a diaphragm. The first chamber can be fluidly coupled to an inlet of the flow controller and an outlet of the flow controller. The second chamber can be coupled to a reference port of the flow controller. The outlet of the flow controller can be coupled to an initially (e.g., substantially) evacuated canister that can be used to collect a sample of ambient air or challenge standard (e.g., during testing).