To obtain a low-pressure-loss physical quantity detection device that can detect a plurality of physical quantities of intake air. A physical quantity detection device of the present invention that detects a plurality of physical quantities of a measured gas flowing in a main passage, the physical quantity detection device includes: a circuit board on which a sensor that detects the plurality of physical quantities and an electronic component that controls the physical quantities are mountable; a circuit board accommodating unit that accommodates the circuit board; and a sub-passage in which a flow sensor is disposed. The circuit board is accommodated in the circuit board accommodating unit on an upstream side of the sub-passage, and disposed in parallel with the measured gas flowing through the main passage.

The flow of well mud being pumped by a drilling rig pump into a wellbore is sensed by monitoring at least one signal from at least one sensor of drilling mud, determining a total well drilling pump mud output rate, and determining an apparent annular mud rate based on the at least one signal and the total pump drilling rate.

A physical quantity sensor detects a physical quantity of a fluid and a sealing resin. The physical quantity sensor is mounted on a circuit board and includes an electrode part electrically connected to the circuit board. The sealing resin is provided on a physical quantity sensor mounting surface, which is formed on the circuit board and equipped with the physical quantity sensor, and covers the electrode part. The physical quantity sensor mounting surface includes a mounting region surface including a place where the physical quantity sensor is provided and a place where the sealing resin is provided and a peripheral region surface extending around the mounting region surface. A wettability of the mounting region surface for the sealing resin in a liquid form is higher than a wettability of the peripheral region surface for the sealing resin in the liquid form.

A physical quantity measuring device includes a housing having a part disposed in a main passage through which a measurement target fluid flows, a sensing element configured to detect a physical quantity of the measurement target fluid, a circuit board disposed in the housing and having a mounting area on which the sensing element is mounted, a potting resin covering an electric connecting portion between the circuit board and the sensing element; and a restricting portion disposed on the circuit board in a vicinity of the mounting area to restrict the potting resin from wetting and spreading out.

Provided is a physical quantity detection device capable of achieving both rigidity improvement and sealability improvement. A physical quantity detection device (20) of the invention includes a housing (100), a cover (200), a chip package (310), and a flow rate sensor (311) supported by the chip package and arranged in a sub-passage. The housing includes: a first adhesive groove 160A which is an adhesive groove to which an adhesive for bonding the cover is applied, extends along a proximal end of the housing, extends in the protruding direction of the housing from the proximal end of the housing to a position on a more distal end side of the housing than the chip package, and is applied with the first adhesive 401; and a second adhesive groove 160B which extends along the sub-passage 134 and is applied with the second adhesive 402. The first adhesive has a higher Young's modulus, and the second adhesive has a higher thixotropy.

A physical quantity measurement device is provided which is capable of measuring a component in a fluid to be measured even when the fluid contains droplets such as fine water droplets. The physical quantity measurement device includes, at an inlet opening (5) of a sub-channel (7), an inflow direction regulator (13) which includes guide pieces (12) each of which is inclined at predetermined angle θ with respect to the flow direction in a main channel (1). The angle θ of inflow direction regulator (13) is set to a value that is greater than 90 degrees in relation to the flow direction of the main channel (1).

The flow of well mud being pumped by a drilling rig pump into a wellbore is sensed by monitoring at least one signal from at least one sensor of drilling mud, determining a total well drilling pump mud output rate, and determining an apparent annular mud rate based on the at least one signal and the total pump drilling rate.

An air flow rate measurement device includes a housing, a flow rate sensing device and a physical quantity sensing device. The flow rate sensing device is located in a flow rate measurement passage of the housing and outputs a signal which corresponds to a flow rate of air flowing in the flow rate measurement passage. The physical quantity sensing device is located in a physical quantity measurement main passage of the housing that is communicated with a physical quantity measurement main passage inlet and a physical quantity measurement main passage outlet of the housing. The physical quantity sensing device outputs a signal which corresponds to a physical quantity of the air flowing in the physical quantity measurement main passage. The housing has the physical quantity measurement main passage outlet as one of a plurality of physical quantity measurement main passage outlets.

In a flow rate measurement device, a flow rate sensing device outputs a signal which corresponds to a flow rate of air flowing in a flow rate measurement passage, and a physical quantity sensing device outputs a signal which corresponds to a physical quantity of the air flowing in a physical quantity measurement passage communicated with a physical quantity measurement passage inlet and a physical quantity measurement passage outlet at a housing. The physical quantity measurement passage has a physical quantity measurement passage inner surface formed at a part of the physical quantity measurement passage located on a side where a back surface is placed. The physical quantity measurement passage outlet has an outlet rectifying surface that is connected to a lateral surface of the housing and an end part of the physical quantity measurement passage inner surface located on a side where the lateral surface is placed.

An airflow meter includes a housing including a base surface, a rear surface, a first side surface, a second side surface, a flow-rate inlet portion, a flow-rate outlet portion, a passage, and a physical quantity inlet portion, a flow rate detector, a board, and a physical quantity detector mounted on a board surface. The physical quantity inlet portion includes a first inner surface, a second inner surface, a third inner surface, and a fourth inner surface. The physical quantity detector is configured to output signals according to a physical quantity of air flowing through a board passage. The board, the first inner surface, the third inner surface, and the fourth inner surface are arranged to reduce a cross-sectional area of the board passage from the base surface toward the rear surface.