A flow rate detector includes: a housing; and a substrate assembly disposed in the housing. The substrate assembly has a flow rate detection element, a temperature detection element, and a circuit board on which the flow rate detection element and the temperature detection element are mounted. The circuit board includes a body portion fixed to the housing, and a protrusion extended to protrude from the body portion. The protrusion has an element fix portion to which the temperature detection element is fixed. The protrusion has a supported portion within a supported range including a position of the element fix portion. The supported range is defined from the element fix portion to a tip end of the protrusion along an extension direction of the protrusion. The supported portion is supported by the housing to suppress a displacement of the element fix portion in a thickness direction of the circuit board.

A flow sensor includes a semiconductor, an electric control circuit, a lead frame, and a spacer. The spacer is disposed in a clearance between the lead frame and the semiconductor device on an opposite side from a joint portion of the semiconductor device with the lead frame on a side of the electric control circuit across the diaphragm disposed therebetween. A surface of the electric control circuit and a part of a surface of the semiconductor device is covered with resin while the air flow sensing unit is exposed. At the joint portion, the semiconductor device is attached to the lead frame via an adhesive.

A Mass Flow Sensor (MFS) is provided and includes an MFS housing, a mounting structure, having a mounting structure top and a mounting structure bottom, wherein the MFS housing is associated with the mounting structure top, a first sensor leg, wherein the first sensor leg extends away from the mounting structure bottom and includes a first temperature measurement device and a heating element. The MFS further includes a second sensor leg, wherein the second sensor leg extends away from the mounting structure and includes a second temperature measurement device and an airfoil structure, wherein the airfoil structure defines an airfoil cavity and is associated with the mounting structure bottom to contain the first sensor leg and the second sensor leg.

The present disclosure provides an intake air flow rate measuring device. The intake air flow rate measuring device includes a flange, a casing, a flow rate sensor, a humidity sensing element, an element terminal, and a humidity terminal. The humidity terminal is spaced away from the element terminal. A portion of the casing between the element terminal and the humidity terminal is defined as a suppressing portion, and a cross-section of the suppressing portion is defined as a suppressing portion cross-section. An end portion of the casing close to the flange is defined as a base portion, and a cross-section of the base portion is defined as a base portion cross-section. The suppressing portion cross-section is set to be smaller than the base portion cross-section.

A physical quantity measurement device for measuring a physical quantity of a fluid includes a housing that includes a bypass flow channel through which a fluid flows and a physical quantity detection unit that detects a physical quantity of the fluid in the bypass flow channel. The housing includes a housing main body made of a dielectric and a covering film that covers at least a part of a surface of the housing main body, and the surface of the housing is positive charged due to positive charges being arranged in the housing main body along the surface of the housing main body or the positive charges being arranged in the covering film along a surface of the covering film.

A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

A compact physical quantity detecting device is provided since it is possible to lower the mounting height of a chip package by accommodating the chip package in a notched board. In the physical quantity detecting device of the present invention, a part in a thickness direction of a support body on which a flow rate detection unit and a processing unit are mounted is accommodated in a notch provided in a printed board.

We disclose herein a flow sensor assembly comprising a first substrate, a flow sensor located over the first substrate, a lid located over the flow sensor, a flow inlet channel, and a flow outlet channel. A surface of the flow sensor and a surface of the lid cooperate to form a flow sensing channel between the flow inlet channel and the flow outlet channel, and a surface of the flow sensing channel is substantially flat throughout the length of the flow sensing channel.

Mass flow meters and mass flow controllers that include mass flow meters are disclosed. A mass flow meter includes a main flow path for a gas, and a bypass with a length, L, within the main flow path. The bypass includes a continuous flow section including a plurality of continuous capillary tubes that each have a length, L. The bypass also includes n flow segments forming n1 spaces within the bypass where n is greater than or equal to 2, and each of the flow segments has a plurality of capillary tubes. The mass flow meter also includes at least one thermal sensor including a sensor tube, and the sensor tube is positioned across at least one of the flow segments to divert a portion of the gas around the at least one of the flow segments and provide a measured flow signal in response to the diverted portion of the gas.