An Ultrasonic flowmeter for measuring the flow of a medium through a measuring tube (3) with at least two ultrasonic transducers (4,5) and at least one control and evaluation unit (6). The measuring tube (3) has an inner wall, the ultrasonic transducers (4, 5) are transmitters (4,5) for transmitting an ultrasonic signal (7) and/or are receivers (4, 5) for receiving the ultrasonic signal, and are arranged offset in the direction of flow such that the respective transmitter (4, 5) transmits an ultrasonic signal (7) in the direction of flow or against the direction of flow during operation. The receiver (4, 5) receives the ultrasonic signal (7) transmitted by the transmitter (4, 5) after at least one reflection on the inner wall of the measuring tube (3), the ultrasonic signal (7) having a first signal component (8) and at least a second signal component (9).

A physical quantity measurement device includes a passage flow channel, a branch flow channel, and a physical quantity detection unit. An inflow region extending from the inflow port and a lateral region laterally arranged to the inflow region are included in at least one of the passage flow channel and the branch flow channel. The physical quantity detection unit is disposed in the lateral region. A guiding surface that guides away from the lateral region in the lateral direction foreign matter is included in at least one of an inner peripheral surface of the passage flow channel and an inner peripheral surface of the branch flow channel at a position upstream of the lateral region.

Disclosed is a flow rate controller in which a clear width (6) of a control gap (4) between a main part (3) and a control element (2), which is deformable according to the pressure in order for the flow rate through the control gap (4) to be kept constant, can be adjusted as a result of the fact that at least one supporting element that adjusts the clear width (6) of the control gap (4) is designed to be movable relative to a main part (3).

A particle sensor uses an electrostatic particle charging section in the form of an ionization chamber. A flow sensor arrangement is used to produce a signal which is representative of the amount of gas flow between the outside of the ionization chamber and the inside of the ionization chamber. This information is indicative of the flow conditions, and can be used to determine when adverse flow conditions are present which may adversely affect the performance or lifetime of the particle sensor.

A system and method for dividing a single mass flow into secondary flows of desired ratios to total flow. Each secondary flow line includes a pressure drop element, an absolute pressure sensor and a differential pressure sensor. The nonlinear relationship between flow and pressures can be transformed into a function of the absolute and differential pressures that has a linear relationship with the flow.

A burner control system for improving burner performance and efficiency. The system may determine fuel and air channel or manifold parameters. Determination of parameters may be performed with a sensor connected across the air and fuel channels. A signal from the sensor may control the parameters which in turn affect the amounts of fuel and air to the burner via a controller. Parameter control of the fuel and air in their respective channels may result in more accurate fuel and air ratio control. One or more flow restrictors in fuel and/or air bypass channels may further improve accuracy of the fuel and air ratio. The channels may be interconnected with a pressure or flow divider. Byproducts of combustion in the exhaust, temperatures of gas and air, flame quality and/or other items may be monitored and adjusted with control of the fuel and air ratio for optimum combustion in the burner.

A system for controlling a flow rate of a fluid through a valve is provided. The system includes a valve and an actuator. An actuator drive device is driven by an actuator motor and is coupled to the valve for driving the valve between multiple positions. The system further includes a differential pressure sensor configured to measure a differential pressure across the valve and a controller that is communicably coupled with the differential pressure sensor and the motor. The controller is configured to receive a flow rate setpoint and the differential pressure measurement, determine an estimated flow rate based on the differential pressure measurement, determine an actuator position setpoint using the flow rate setpoint and the estimated flow rate, and operate the motor to drive the drive device to the actuator position setpoint.

Fluid control systems, including mass flow control systems, mass flow ratio control systems, and mass flow and ratio control systems, as well as corresponding methods for fluid control are provided. These systems allow one shared pressure sensor to be used for multiple flow channels, and a controller which can accurately determine mass flow on the basis of fluid pressure detected by this shared pressure sensor.

A Venturi air flow sensor and control system includes a Venturi housing comprising with an inlet section, an outlet section, and a reduced diameter horn shaped center section connecting the inlet section to the outlet section with a damper. A high pressure sensor tube with downstream openings extends across the inlet section on the outlet section and a low pressure sensor tube with downstream openings extends across the reduced diameter horn shaped section. The pressure from the low pressure sensor tube and the pressure from the high pressure sensor tube are connected to a controller. From the high pressure and the low pressure the controller determines the air flow and based on air flow operates the damper.

A system for controlling activity in a combustion chamber. The system does not necessarily need to be mechanically adjusted and yet may provide precise control of a fuel air mixture ratio. A sensing module of the system may have a mass flow sensor that relates to air flow and another sensor that relates to fuel flow. Neither sensor may need contact with fuel. Fuel and air to the system may be controlled. Pressure of the fuel and/or air may be regulated. The sensors may provide signals to a processor to indicate a state of the fuel and air in the system. The processor, with reliance on a programmed curve, table or the like, often based on data, in a storage memory, may regulate the flow or pressure of the fuel and air in a parallel fashion to provide an appropriate fuel-air mixture to the combustion chamber.