A physical quantity measuring device is configured to measure a physical quantity of a fluid. The physical quantity measuring device includes: at least two humidity detection parts configured to output a humidity signal corresponding to a humidity of the fluid; and an abnormality determination part configured to determine that an abnormality has occurred in the humidity detection parts in response to that a difference between the humidity signals obtained from the two humidity detection parts exceeds an abnormality determination threshold.

A physical quantity measurement device includes a housing forming a measurement flow path in which a sensor support supports a physical quantity sensor. The measurement flow path includes a sensor path in which the physical quantity sensor is disposed, an upstream curved path between the sensor path and an inlet, and a downstream curved path between the sensor path and an outlet. The housing includes a measurement narrowed portion that gradually narrows the measurement flow path in a direction from the inlet toward the physical quantity sensor. An upstream end of the sensor support is provided upstream of the measurement narrowed portion in an arrangement cross section along an imaginary straight line passing through the physical quantity sensor and extending in an arrangement direction in which the upstream curved path and the downstream curved path are arranged.

A physical quantity measurement device includes a housing forming a measurement flow path including a measurement inlet and a measurement outlet. The measurement flow path includes a sensor path in which a physical quantity sensor is disposed, an upstream curved path curved to extend from the sensor path toward the measurement inlet, and a downstream curved path curved to extend from the sensor path toward the measurement outlet. An inner surface of the housing includes an upstream outer curved surface that defines an outer outline of a curved part of the upstream curved path, and a downstream outer curved surface that defines an outer outline of a curve part of the downstream curved path. A degree of recess of the downstream outer curved surface is larger than a degree of recess of the upstream outer curved surface.

The physical quantity measurement device for measuring the physical quantity of the fluid has a measurement flow passage through which the fluid flows; a detection element for detecting the physical quantity of the fluid; a plate-shape physical quantity detector that detects the physical quantity of the fluid by the detection element in the measurement flow passage; a protection body that protects the physical quantity detector; a body recess arranged on the outer surface of the protection body at a position separated from the physical quantity detector in the orthogonal direction, which is orthogonal to a thickness direction of the physical quantity detector.

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).

An engine system includes: an engine main body; an intake pipe; a mass flow sensor that is provided in the intake pipe and outputs a measurement value of an amount of air passing through the intake pipe; an exhaust pipe; a removal device that is provided in the exhaust pipe and removes an air pollutant included in an exhaust gas passing through the exhaust pipe; a recirculation pipe; a recirculation valve that controls a flow rate of the exhaust gas flowing from the recirculation pipe to the intake pipe; a regeneration control unit that closes the recirculation valve; an air amount calculation unit that calculates a theoretical value of an amount of air flowing to the intake side of the engine main body on the basis of a quantity of state of the engine main body during the regeneration process; and a correction unit.

The hydrogen production system for internal combustion engines includes an intake air scoop, a vacuum block having an air input port system for receiving air from the intake air scoop, a water reservoir connected to the vacuum block for providing water to be mixed with the air in the vacuum block, at least one primary generator assembly with an inlet port for receiving the air/water vapor mixture from the vacuum block and producing a mixture of hydrogen, produced oxygen, and fine hydrogen production vapor from a partially oxidized water fog, and a plurality of secondary hydrogen generator assemblies connected to the primary generator assembly for receiving this mixture. The engine vacuum draws this mixture into the intake manifold to provide an ideal fuel mixture for the engine.

An air duct system for passing an air flow emanating from an air outlet to a measurement device for detecting parameter measurement values for at least one parameter of the air flow, includes at least one collecting unit for collecting the air flow emanating from the air outlet. That one collecting unit can be disposed on the air outlet so that a contact surface of the collecting unit encloses at least one outlet opening of the air outlet circumferentially. The collecting unit includes a wall defining a continuous air duct with an inlet end section and an outlet end section. In order to improve the measurement of the parameter of the air flow, the air duct system includes at least one measurement chamber that is communicatively connected to a section of the air duct enclosed by the inlet end section, which, as a measurement chamber that is otherwise closed relative to the surroundings, either contains at least one pressure sensor or comprises at least one connection for communicatively connecting the measurement chamber to a pressure measurement device.

The speed of a turbocharger may be estimated using data from sensors that are readily available in most engine management systems. In some cases, a pressure measurement from a MAP sensor may be used, in combination with one or more computational models, to provide an efficient, lower cost estimate of turbo speed that can be used to control operation of the engine and/or the turbocharger.

An apparatus and a system is provided that may be utilized to determine air flow through an air filter and/or a plurality of air filters. The present invention utilizes a demonstration apparatus to illustrate the differences in air flow and air restriction between a plurality of different air filters and filtration media. The apparatus and system utilizes a common plenum which subjects the plurality of air filters to the same differential pressure. The air flows through a first side of the air filter and is measured on the second side of the air filter by utilizing a wind meter or similar device to gauge the amount of air flow velocity of the second side of the filter. Additionally, the apparatus and system utilizes a display means to illustrate the differing air velocity through the second side of the air filter.