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 U-shaped tube is used to measure the mass flow rate of the fluid using both thermal method and the Coriolis principle simultaneously. Two resistant coils are wound on the tube to do the thermal measurement and an excitation coil and two optical sensors are used to do the Coriolis flow measurement. It takes the advantages of both technologies and create a flow sensor which is super accurate, gas type insensitive, long-term stable and fast responsive without too much pressure drop.

An HVAC system and method for characterizing a chosen VAV valve involves measuring the valve's volumetric flow rate versus valve position at just one or at some other limited number of data points and comparing that to the average characteristics a rather large group of similar valves. A custom characterization of airflow versus valve position for the chosen VAV valve is then created based on a difference between the characteristics of the chosen valve and that of the group of valves. In some examples, the VAV valve is of a venturi style such that a generic characterization of the group of valves is substantially linear when their flow rates are expressed logarithmically.

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 invention relates to a measuring system for determining a dispensed amount of hydrogen of a hydrogen dispensing location from a hydrogen dispensing unit present there to a receiving tank including a measuring unit. The measuring unit can have a flowmeter, wherein the measuring system is designed to establish a fluid-tight connection between the hydrogen dispensing unit and the receiving tank. Furthermore, the flowmeter has an active cooling. The invention further relates to a measuring method for determining a dispensed amount of hydrogen.

The flow rate measurement device according to one aspect of the present invention comprises a heating unit for heating a fluid; temperature sensing units that are provided flanking the heating unit in the direction of fluid flow, and that sense the temperature of the heated fluid; a flow rate calculation unit that calculates the flow rate of the fluid on the basis of a sensing signals outputted from the temperature sensing units; angle calculation unit for calculating the tilt angle of the temperature sensing units with respect to a specific reference plane; a storage unit that stores the relation between the flow rate, the tilt angle, and a flow rate correction value; and a flow rate correction unit that corrects the flow rate by using the flow rate correction value stored in the storage unit.

A gas meter is configured for diagnostics using differential pressure (DP) measurements. The configurations include executable instructions to actively manage the DP sensor. These instructions active the DP sensor only during stable flow and, where applicable, for a defined test time period. This feature manages power consumption to maintain battery life with acceptable standards or regulations.

A working condition monitoring system for a positive displacement rotary flow meter determines flow rate and differential pressure information for logging to determine a history of such data for a meter in the field. Deviation from good working data established for the meter model may be used such as to indicate maintenance and/or repair needs. Mechanical or other wear in a meter may lead to higher differential pressure measures for a given flow rate (or a lower measured flow rate for a given differential pressure) than is true for a meter in good working order. A corrective factor responsive at least to a current different pressure may be applied to correct a measure of flow rate that is determined in response to a measure of impeller rotation to account for additional flow of gas through the meter that is not driving the impeller(s).

Mass flow controllers and methods for controlling mass flow controllers are disclosed. One method includes providing a process gas through a flow sensor of the mass flow controller, obtaining a gas-adjusted sensitivity coefficient for the flow sensor, and obtaining gas-adjusted nonlinearity data for the flow sensor. The method also includes producing gas-adjusted characterization data for the flow sensor using the gas-adjusted sensitivity coefficient and the gas-adjusted nonlinearity data. A flow value from the gas-adjusted characterization data is obtained using a flow sensor signal from the flow sensor, and the flow value is used along with a setpoint signal to control a valve of the mass flow controller.

A flow rate diagnosis apparatus includes: a main line in which a tank having a volume is provided; a branch line that branches from the main line on an upstream side of the tank; a first open close valve provided in the branch line; a second open close valve provided in the main line; a dead volume defined from the diagnosis object as an upstream end and the first open close valve and the second open close valve as downstream ends; and a second pressure control mechanism that controls a fluid flowing through the main line such that the pressure of the fluid in the dead volume is maintained at a second setting pressure during an inflow mode during which the fluid is caused to flow into the tank by closing of the first open close valve and opening of the second open close valve after a preparation mode.