A physical quantity measurement device measures a physical quantity of a fluid. A detection unit has a physical quantity detector that detects a physical quantity of the fluid in a measurement flow channel. A housing accommodates at least a part of the detection unit and forms the measurement flow channel. The housing includes a housing attachment that is attached to a predetermined attaching target, and a position holder holding a position of the detection unit by contacting the detection unit. The housing includes an inward part positioned inward of the attaching target and an outward part positioned outward of the attaching target. The position holder is provided inward of the housing attachment in an alignment direction along which the inward part and the outward part are aligned.

Methods and apparatuses associated with flow sensing devices are provided. An example flow sensing device may include a sensing element disposed at least partially within the housing, and a plurality of channels disposed within the housing defining a flow path configured to convey a flowing media through the flow sensing device, wherein the flow path is disposed proximate the sensing element such that at least a portion of the flowing media makes direct contact with the sensing element.

A thermal airflow sensor includes a sensor element, a bonding wire, a resin, and a protective film. The sensor element has a thin-wall portion. The thin-wall portion has a heating resistor. The bonding wire is electrically connected to the sensor element. The resin covers the bonding wire. The protective film is formed on a surface of the sensor element so that the heating resistor is exposed. The protective film has at least a slit between the resin and the thin-wall portion.

A flow sensor assembly comprising a first substrate, a flow sensor located over the first substrate, a lid located over the first substrate and the flow sensor, a flow inlet channel, a flow outlet channel, and an overmold laterally encircling the flow sensor. The overmold is in contact with the side walls of the flow sensor, and extends between the flow sensor and the lid such that the overmold, the flow sensor, and the lid define a flow sensing channel between the flow inlet channel and the flow outlet channel. the lid and the encapsulation cooperate to define the flow inlet channel and the flow outlet channel.

A flow sensor including a fluid flow path, a first sensor configured to determine a first measurement of a thermal diffusivity and/or a viscosity of a fluid in the fluid flow path, a second sensor configured to determine a second measurement of a fluid flow velocity and/or a volumetric flow rate of the fluid in the fluid flow path, and at least one processor configured to adjust the second measurement based on the first measurement. A method including receiving fluid in a fluid flow path of a flow sensor, determining a first measurement of a thermal diffusivity and/or a viscosity of the fluid in the fluid flow path, determining a second measurement of a fluid flow velocity and/or a volumetric flow rate of the fluid in the fluid flow path, and adjusting the second measurement based on the first measurement.

A physical quantity measurement device includes a physical quantity detector and a support plate part superposed on a back surface of the physical quantity detector to support the physical quantity detector. The physical quantity detector includes a recessed part on the back surface, and a membrane part defining a bottom surface of the recessed part and being provided with a detection element for detecting a physical quantity of a fluid in a measurement low path. An area of the support plate part covering the recessed part includes a communication hole communicating with the recessed part. A peripheral edge portion of a hole opening, which is an end of the communication hole adjacent to the recessed part, is spaced apart, toward the inside, from a peripheral edge portion of a recess opening, which is an end of the recessed part adjacent to the support plate part.

A physical quantity measurement device includes a physical quantity detector that detects a physical quantity of a fluid in a measurement flow path, a physical quantity processor that receives a detection result of the physical quantity detector, and a support plate part that supports the physical quantity detector and the physical quantity processor. The support plate part includes a detector support portion to which the physical quantity detector is attached, and a processor support portion that is located at a position spaced apart from the detector support portion and to which the physical quantity processor is attached. Between the detector support portion and the processor support portion, a heat transfer regulation portion is provided to regulate heat transfer from the processor support portion to the detector support portion.

An object is to improve measurement accuracy of a flow rate measurement device. A flow rate measurement device including: a first void which is formed of one surface of the support body and one surface of the circuit board; a second void which is formed of a surface opposite to the one surface of the circuit board and the housing; and a third void which is formed of a surface opposite to the one surface of the support body and a cover.

A flow rate measurement device includes a housing having a main flow path, a sub flow path formed inside the housing to allow a part of a fluid to be detected flowing through the main flow path, an inlet portion that allows the fluid to be measured flowing in the main flow path to flow into the sub flow path, an outlet portion that allows the fluid to be measured flowing in the sub flow path to flow out to the main flow path, a flow rate detection unit that is provided between the inlet portion and the outlet portion in the sub flow path and detects a flow rate of the fluid to be measured flowing through the sub flow path, and a communication hole that is provided between the flow rate detection unit and the outlet portion and communicates the sub flow path and the main flow path.

To obtain a physical quantity detection device capable of reducing an intake amount of air accompanied by foreign matter. A physical quantity detection device (20) of the invention includes a housing arranged in a main passage through which a measurement target gas (2) flows. The housing is provided with a second sub-passage (B) that takes in a part of the measurement target gas (2) flowing in the main passage, a circuit chamber (135) that accommodates a pressure sensor (320) that detects a pressure of the measurement target gas (2), and a pressure introduction passage (170) having one end opened in the middle of the second sub-passage (B) and the other end opened in the circuit chamber (135) and capable of introducing the pressure of the measurement target gas (2) from the second sub-passage (B) into the circuit chamber (135). In the pressure introduction passage (170), an introduction port (171) is arranged at a position offset outward from a side wall surface (152b) of the second sub-passage (B).