A flow sensor configured to measure the flow of a fluid flowing through a tubular structure comprises a first detection unit that is configured to detect flows above a predefined lower flow level representing the lowest flow that can be measured by the first detection unit and a second detection unit that is configured to estimate the flow below the lower flow level (on the basis of the temperature difference between the surroundings and a fluid). The second detection unit is configured to estimate the flow below the lower flow level on the basis of one or more measurements made in a flow-calibration-area in which the flow sensor can detect the flow and in which the flow depends on the temperature difference.

A mass flow control apparatus having a monolithic base. The monolithic base has a gas inlet, a gas outlet, a first flow component mounting region, a second flow component mounting region, and a third flow component mounting region. The first flow component mounting region has a first inlet port and a first outlet port, the first inlet port being fluidly coupled to the gas inlet of the monolithic base. The second flow component mounting region has a second inlet port, a second outlet port, and a first auxiliary port.

The present disclosure provides an air flow rate measuring including a casing and a sensor. The casing includes a main-bypass passage that defines an inlet and an outlet, a sub-bypass passage that branches off from the main-bypass passage at a branching area, and a guiding wall that changes, at a position upstream of the branching area, a flow direction of the passing air taken in from the inlet. The inlet and the guiding wall are arranged in an arranging direction along a flow direction of the intake air in the duct. The guiding wall includes an inlet side surface that faces the inlet and is not perpendicular to the arranging direction.

A control means configured to perform flow rate control in which the control means outputs a control signal to a flow control valve to control a valve opening such that a measured flow rate of gas measured by a flow meter matches a set flow rate adjusts intensity of the control signal such that an absolute value of a change amount of the valve opening becomes larger as measured temperature of the gas measured by a thermometer becomes further higher than reference temperature, while the absolute value of the change amount of the valve opening becomes smaller as the measured temperature becomes further lower than the reference temperature. Thereby, change of response time on changing the valve opening of the flow control valve due to the difference between the measured temperature of the gas and the reference temperature can be reduced.

Mass flow sensors, mass flow meters, and methods of making the same are disclosed. A flow sensor may include one sensor tube, a pair of sensor wires wound around the sensor tube, and a covering layer disposed in the surroundings of the sensor tube and the sensor wires. The covering layer includes a first covering layer disposed in contact with the surface of the sensor tube, a second covering layer disposed in contact with the surface of the sensor wires, a third covering layer disposed in a space surrounded by the first covering layer and the second covering layer, and a fourth covering layer disposed so as to cover the whole of the sensor wires wound around the sensor tube. In variations, the covering layer includes one or two organic materials chosen from polyamide-imide and polyimide, and the film thickness of the first covering layer is 10 micrometers or more.

An apparatus for making a flow determination with respect to a flow through a fluid conduit such as a domestic water pipe, the fluid conduit comprising a wall having an inner surface surrounding a flow space through which the fluid flows and an outer surface, the apparatus comprising: a first temperature sensor arranged to be mounted on the outer surface of the fluid conduit and arranged to generate a first temperature signal indicative of a first temperature being the temperature of the outer surface; a second temperature sensor arranged to be positioned spaced apart from the first temperature sensor and to generate a second temperature signal indicative of a second temperature being the ambient temperature outside of the fluid conduit; and a processor having inputs for the first and second temperature signals; in which the processor has an output for the flow determination and is arranged to make the flow determination by determining a measure of the convergence of the first and second temperatures over time.

An electric measurement method and apparatus for detecting a mass by an electric capacity (permittivity) or a material's dielectric constant, or alternatively, electric inductance (permeability). The mass may be any phase or combination of phases. The mass may be stationary or flowing. It may comprise discrete particles such as grain, or manufactured products such as ball bearings or threaded fasteners, etc. The mass may be a flow element in a rotameter or similar flow measurement device. The sensor comprises a volume which may be completely full or only partially full of the material. The material may be discrete components or a continuum. Sensor signals may be received by existing planter monitoring systems. In some embodiments the flow sensors are positioned external to the application port. In some embodiments sensors may be utilized which are responsive to the refractive index variation of specific chemicals.

A gas sensor that can clamp around a gas line to detect gas flow. The sensor can detect gas flow and notify other devices using wireless communication. Other conditions such as gas flow time, etc. can trigger notification. The sensor may also include a shut-off valve that can be controlled remotely or invoked under certain conditions.

A sensor unit for measuring a mass flow rate of a liquid hot-melt adhesive is disclosed. The sensor unit includes a flow channel for the hot-melt adhesive, a first temperature measurement device positioned at a first position in the flow channel, a second temperature measurement device positioned at a second position in the flow channel and a heating device assigned to the second temperature measurement device, and a control unit for controlling the heating device and for measuring the mass flow rate. The controller is configured to adjust the temperature of the heating device assigned to the second temperature measurement device to a value, to determine the heating power for heating the heating device assigned to the second temperature measurement device, and to calculate the mass flow rate in the flow channel. The first and second temperature measurement devices are arranged substantially parallel to each other in the flow channel.

The present disclosure relates to a method and an apparatus for measuring a flow rate through a vessel, such as a conduit or pipeline. The method comprises providing a reference parameter, measuring a first parameter at a first position at the vessel and determining a difference between the first parameter and the reference parameter. The flow rate through the vessel is determined based on the difference between the first parameter and the reference parameter.