A mass flow sensor assembly for a mass flow controller or a mass flow meter comprises a mass flow sensor comprising a capillary tube held by a first corner support and a second corner support formed separately from each other. The capillary tube comprises a sensor portion which is located between the two corner supports, and wherein the two corner supports each have an arc-shaped groove in which the capillary tube is partially received. In addition, a method of manufacturing a mass flow sensor assembly is described.

Methods and apparatus for non-intrusively measuring fluid flow in a conduit, such as a pipe or tubing. The apparatus includes an insulator having self-adhesive inner surface attachable to the conduit, a temperature sensor on the inner surface of the insulator that senses the conduit surface temperature, a heat source on the inner surface of the insulator that imparts heat into the conduit, and a microcontroller connected to the heat source activator and the sensor assembly. In one embodiment, a baseline conduit temperature is measured, and the heat source raises the temperature of the conduit by a predetermined amount. When the conduit reaches target temperature, the heat source is deactivated and the cooling time for the conduit to return to its baseline temperature is measured. Fluid flow rate is determined from the cooling time, the temperature rise within a predetermined time, a temperature drop within a predetermined time, and/or a temperature gradient 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 thermal flowmeter includes: a first thermal resistive element disposed on a pipe and sensing a first temperature of a fluid; a second thermal resistive element disposed on the pipe downstream relative to the first thermal resistive element and sensing a second temperature thereof; a control unit causing the second thermal resistive element to generate heat so that the second temperature is kept higher than the first temperature by a predetermined value; a power measurement unit measuring a power supplied to the second thermal resistive element; a temperature difference gradient calculation unit calculating a gradient of a difference between the second and first temperatures; a power compensation unit compensating the measured power based on the gradient of the difference and a value of the power when no fluid is in the pipe; and a flow rate calculation unit calculating a flow rate of the fluid based on the compensated power.

A flow sensor configured to detect a fluid flow of a liquid inside a pipe portion is disclosed. A thin film thermal mass flow sensor has a substrate defining a thickness from an upper side opposite a bottom side. The upper side of the substrate supports a resistive heating circuit, a first temperature sensor circuit and a second temperature sensor circuit. The resistive heating circuit is disposed between the first and second temperature sensor circuits. The circuits are electrically connected respectively to a plurality of leadwires configured to be attachable to electronic equipment. A thermally conductive membrane is configured to separate the fluid flow of the liquid inside the pipe portion from the thin film thermal mass flow sensor. A thermally conductive bond connects the bottom side of the substrate of the thin film thermal mass flow sensor to the thermally conductive membrane.

A thermal type flowmeter includes a sensor and a flow-rate calculating unit. The sensor includes a heater that heats a fluid to be measured. The sensor is configured to output a sensor value corresponding to a state of thermal diffusion in the fluid heated by the heater which is being driven in such a manner that a difference between a temperature of the heater and a temperature of the fluid at a location free from thermal influence of the heater is equal to a predetermined temperature difference. The flow-rate calculating unit is configured to calculate a flow rate of the fluid from the sensor value by using a flow-rate calculation equation, sensor value=transformation coefficient Alog (flow rate).sup.2+transformation coefficient Blog (flow rate)+transformation coefficient C.

A thermal flowmeter includes a casing, a ferrule, a measuring tube penetrating through the ferrule, a sensor for flow rate detection, a joint shaft movably supported by end portions of the casing, one end portion of the joint shaft being connected to the measuring tube and the ferrule with a through hole of the joint shaft and a hollow portion of the measuring tube communicating with each other, the other end portion of the joint shaft sticking out of the casing, and a screw thread-fitted to each of the end portions of the casing, and including a pressing portion pressing the joint shaft into an inside of the casing. A seal structure includes a first tapered surface formed on the ferrule and a second tapered surface formed on the joint shaft and fitting the first tapered surface, and is provided between the ferrule and the joint shaft.

A multi-purpose Micro-Electro-Mechanical Systems (MEMS) thermopile sensor able to use as a thermal conductivity sensor, a Pirani vacuum sensor, a thermal flow sensor and a non-contact infrared temperature sensor, respectively. The sensor comprises a rectangular membrane created in a silicon substrate which has a thin polysilicon layer and a thin residual thermal reorganized porous silicon layer both attached on its back side, and configured to have its three sides clamped to the frame formed in the silicon substrate which surrounds and supports the membrane and the other side free to the frame, a cavity created in the silicon substrate, positioned under the membrane and having its flat bottom opposite to the membrane, its three side walls shaped as curved planes and the other side wall shaped as a vertical plane, a heater or an infrared absorber positioned on the membrane, close to and parallel with the free side of the membrane and a thermopile positioned on the membrane and consists of several thermocouples connected in series and having its hot junctions close to the heater and its cold junctions extended to the frame.

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.

Example systems, apparatuses, and methods are disclosed sensing a flow of fluid using a thermopile-based flow sensing device. An example apparatus includes a flow sensing device comprising a heating structure having a centerline. The flow sensing device may further comprise a thermopile. At least a portion of the thermopile may be disposed over the heating structure. The thermopile may comprise a first thermocouple having a first thermocouple junction disposed upstream of the centerline of the heating structure. The thermopile may further comprise a second thermocouple having a second thermocouple junction disposed downstream of the centerline of the heating structure.