Abstract: 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.

Abstract: A device for measuring the rate of flow of a fluid comprising. The device includes a heating element, a housing, and a detector. The heating element is located in an interior of the housing, the housing defining a first thermal path from the heating element to a first region of an exterior of the housing and a second thermal path from the heating element to a second region of the exterior of the housing. The detector is configured to detect a property associated with transfer of heat from the heating element to the exterior of the housing. The first thermal path has a first thermal conductivity and the second thermal path has a second thermal conductivity. The first thermal conductivity is greater than the second thermal conductivity. The first region of the exterior of the housing is smaller than the second region of the exterior of the housing.

Abstract: A sensor element is provided for detecting at least one property of a fluid medium. The sensor element comprises at least one housing having at least one inflow opening accessible to the fluid medium. At least one pressure sensor for detecting a pressure of the fluid medium is situated in the inflow opening. In the inflow opening in front of the pressure sensor, a plurality of ribs project from at least one wall of the inflow opening into the inflow opening.

Abstract: A physical quantity measuring device detects a physical quantity of gas flowing in a flow passage. The physical quantity measuring device includes a sensor element that outputs a detection signal according to the physical quantity, a case that is provided to the flow passage and houses the sensor element, and a protrusion that protrudes from a passage wall surface facing the flow passage. The case includes a measurement chamber that houses the sensor element and an inflow port that is configured to cause a part of gas flowing in the flow passage to flow into the measurement chamber therethrough. The protrusion is configured to guide gas flowing along the passage wall surface toward the inflow port.

Abstract: An air mass flowmeter with a housing having an air-guiding path in which an air mass sensor element is arranged on a sensor element carrier in the housing and is electrically connected to a circuit carrier by connection wires. The circuit carrier is also arranged in the housing the air mass sensor element is positioned accurately in the air-guiding path by a positioning element that engages into a positioning element receptacle formed in the sensor element carrier.

Abstract: A physical quantity measurement device measures a physical quantity of a fluid. The device includes a passage flow channel, a branch flow channel, a flow channel partition portion that separates the passage flow channel and the branch flow channel to have the branch flow channel branch off from the passage flow channel, and a physical quantity detector. The flow channel partition portion has a partition top portion as an upstream-side end that is not exposed through the inflow port.

Abstract: A method for avoiding a measurement error of an air flow sensor for a vehicle includes an engine control unit (ECU) which predicts, in advance, occurrence of the contamination by foreign materials included in the air or condensation of moisture on a sensor measurement plate of the air flow sensor, and performs an operation for preventing the contamination by foreign materials or the condensation of moisture when the occurrence is predicted, to avoid the measurement error of the air flow sensor due to the contamination by foreign materials or the condensation of moisture on the sensor measurement plate.

Abstract: A flow sensor assembly including a top flowtube that defines an inlet port, an outlet port, and a main channel. An inlet flow channel fluidly may connect the inlet port of the flow sensor assembly to the main channel. An outlet flow channel fluidly may connect the main channel to the outlet port. The bottom flowtube may include a shroud which acts as a cover over an electronic circuit board. The shroud may eliminate a step, created by the flow sensor, to provide a continuous flow path over the sensor. The channels may be formed to utilize the entire footprint of the flow sensor assembly.

Abstract: In accordance with one aspect of the present invention there is provided an electronic smoking device comprising a flow channel and an atomizer. The flow channel can comprise an incoming airflow opening, an incoming airflow pathway, a sensor assembly, and an outgoing airflow opening. The atomizer can be fluidly coupled to the flow channel. The flow channel can be configured to direct an airflow from the incoming airflow opening, through the incoming airflow pathway, over the sensor assembly, and through the outgoing airflow opening. The electronic smoking device can further be configured to pass the airflow over the atomizer.

Abstract: A sensor system is provided for determining at least one parameter of a fluid medium flowing through a channel structure, e.g., an air mass flow of an internal combustion engine. The sensor system has a sensor housing, e.g., a plug-in sensor that is introduced or can be introduced into a flow tube, in which the channel structure is formed, and at least one sensor chip, situated in the channel structure, for determining the parameter of the fluid medium. The sensor housing has an inlet into the channel structure, oriented opposite a main direction of flow of the fluid medium, and an outlet from the channel structure. The channel structure includes a main channel and a measurement channel. The measurement channel branches off from the main channel. The sensor chip is in the measurement channel. The main channel and the measurement channel discharge together into the outlet from the channel structure.

Abstract: The cross-sectional area of a reduced passage increases at a constant ratio from a maximum reduction part where a cross-sectional area of the reduced passage becomes the smallest toward a downstream side. The cross-sectional area of the reduced passage is equal to the cross-sectional area of a bypass passage at a downstream end of a cross-sectional area increasing region intersecting with a wall surface of the bypass passage. (Cross-sectional area increase ratio)=(B?A)/X is satisfied. A [mm2] is the cross-sectional area of the reduced passage at an upstream end of the increasing region. B [mm2] is the cross-sectional area of the reduced passage at the downstream end of the increasing region. X [mm] is a distance from the upstream end to the downstream end of the increasing region along an air flow direction through the reduced passage. The ratio is 1.5 [mm2/mm] or smaller.

Abstract: A flowmeter (5) having a sensor assembly (10) connected to meter electronics (20) is provided. The sensor assembly (10) comprises at least one driver (104), at least one pickoff (105), and a conduit array (300). The conduit array (300) comprises a plurality of small conduits (302) therein that are configured to receive a process fluid, and further configured to selectably adjust the beta ratio of the flowmeter (5).

Abstract: An assembly for the control of the flow of a fluid stream is provided, the assembly comprising a fluid flow conduit having a longitudinal axis; an inlet in the conduit for the fluid stream being processed; an outlet in the conduit for the fluid stream being processed; a control fluid feed assembly having an inlet for a control fluid; wherein the conduit comprises a control portion having one or more apertures therein, the control portion being disposed between the inlet and the outlet of the conduit, the one or more apertures being in flow communication with the inlet for the control fluid in the flow control assembly and extending in a direction at an angle to the longitudinal axis of the fluid flow conduit; whereby in use the control fluid supplied to the inlet of the control fluid assembly is caused to flow into the conduit through the one or more apertures.

Abstract: A measurement flow path is formed in a detector that makes up a thermal type flow sensor. A temperature sensor is disposed on an upstream side, and a heater is disposed on a downstream side in a fluid flow direction of the measurement flow path. Furthermore, a heat transfer preventing wall is disposed between the temperature sensor and the heater. Preferably, a rectifying means such as an orifice or the like is disposed on the downstream side of the heat transfer preventing wall, and between the temperature sensor and the heater.

Abstract: The present invention aims to provide a thermal flow meter capable of avoiding pollutants guided to an outer circumference side of the bypass passage by virtue of a centrifugal force or particle or liquid pollutants that are not centrifugally separated from reaching a heat transfer surface of an air flow sensing portion and obtaining high measurement accuracy. In the thermal flow meter of the present invention, the bypass passage has an upstream side curved path 390 formed in a curved shape along an unique plane at least in an upstream side from an air flow sensing portion 602 in a flow direction of the measurement target gas 30, and a branching wall 378 formed from a downstream side of the upstream side curved path 390 to a downstream side of the air flow sensing portion 602.

Abstract: A sensor housing includes an inlet flow port, an outlet flow port, a flow sensing region, and a flow channel extending between the inlet flow port, the flow sensing region and the outlet flow port. The flow channel defines a flow path between the inlet flow port and the flow sensing region that is contorted in three-dimensions. The three-dimensional contorted flow path between the inlet flow port and a flow sensing region may include a particle collection region that is configured to decelerate a fluid and collect particles that are released from the fluid. The deceleration of the fluid flow and/or one or more changes in the direction of fluid flow along the contorted three-dimensional flow path may cause dust and/or other particulate matter to be released from the fluid prior to reaching a sensor in the sensing region.

Abstract: An airway adaptor includes: an airway case; and an expired gas guiding portion which is connected to the airway case to introduce a respiratory gas to the airway case. The airway case includes: a first respiratory gas flow path in which the respiratory gas flows in a first direction; and a second respiratory gas flow path in which the respiratory gas flows in a second direction opposite to the first direction.

Abstract: A sensor device for detecting at least one flow property of a fluid medium, including at least one sensor housing, in which at least one electronic module having at least one flow sensor for detecting the flow property is accommodated. At least one pressure sensor and at least one humidity sensor are accommodated inside the sensor housing, at least the pressure sensor and optionally also the humidity sensor is situated inside the sensor housing independently of the electronic module.

Abstract: A sensor device for detecting at least one flow property of a fluid medium. The sensor device includes at least one sensor housing, in which at least one electronic module having at least one flow sensor for detecting the flow property is accommodated. The electronic module is at least partially accommodated in at least one electronic space. Furthermore, at least one pressure sensor and at least one humidity sensor are accommodated inside the sensor housing. The pressure sensor and also the humidity sensor are at least partially accommodated in at least one sensor space, which is designed separately from the electronic space.

Abstract: An apparatus and method for monitoring a flow of liquid in a pipe are provided. The apparatus may include a temperature sensor attached to a pipe of a heat exchanger system to measure a temperature of the pipe, and a controller to determine whether a liquid is present in the pipe, based on a change in the measured temperature.

Abstract: A method of thermal inspection of a component defining at least one internal passageway at a thermal equilibrium state with its surrounding environment, the method includes: capturing a sequence of thermal indications of a surface of the component, delivering an airflow pulse at the thermal equilibrium state of the at least one internal passageway into the at least one internal passageway, and receiving a temperature response signal as a function of time based on the received thermal indication. The method also includes determining a level of blockage of the at least one internal passageway based on the temperature response signal.

Abstract: A sensor device for detecting a flow property of fluid medium, e.g., an air flow in the intake tract or the charge air tract of an internal combustion engine, includes: a sensor housing introduced into the air flow and having at least one housing body, at least one cover, and at least one channel through which the fluid medium flows; a sensor element for detecting the flow property, the sensor element being held on a top side of a carrier. The carrier is situated at least partially in the channel and has a cross section which becomes wider in parallel with the main flow direction of the fluid medium at the location of the sensor element in a sectional plane in parallel to the main flow direction of the fluid medium in the channel.

Abstract: A flow sensor system including a flow sensor assembly is provided. The sensor assembly may be configured to allow fluid flow through a flow conduit. A flow disrupter may be disposed in the flow conduit to impart disturbances to the fluid flow. A by-pass channel may be in fluid connection with the flow conduit and may be arranged to have a geometrical relationship relative to the flow conduit and the flow disrupter to affect flow characteristics in the bypass channel. One or more sensors may be disposed in the by-pass channel to generate a signal responsive to the flow characteristics in the bypass channel. In a first flow regime, the flow characteristics in the bypass channel may effect an amplitude response of the sensor, and in a second flow regime, the flow characteristics may effect a temporal response of the sensor.

Abstract: A flow sensor includes a main flow body, a laminar flow element, a first bypass tap, and a second flow element sensor tap. The main flow body has a first main flow port, a second main flow port, a main flow channel, a first bypass tap, a second bypass tap, and a bypass flow channel. The laminar flow element is disposed within the main flow channel. The bypass flow channel has a cross sectional area, and the first bypass tap and the second bypass tap each have a cross sectional area that is greater than the maximum cross sectional area of the bypass flow channel.

Abstract: A flow sensor includes a main flow body, a laminar flow element, and first and second bypass channels. The first bypass channel is formed in, and extends at least partially around, the outer surface of the laminar flow element, and is in fluid communication with the main flow channel and defines a first bypass flow passage between the laminar flow element and the main flow body. The second bypass channel is formed in, and extends at least partially around, the outer surface of the laminar flow element, and is in fluid communication with the main flow channel and defines a second bypass flow passage between the laminar flow element and the main flow body.

Abstract: A flow sensor includes a main flow body, a laminar flow element, a first main flow body sensor tap, a second main flow body sensor tap, and a bypass flow body. The bypass flow body is coupled to the main flow body and has a first bypass flow port, a second bypass flow port, and a bypass flow channel between the first and second bypass flow ports. The flow restrictor is disposed within the bypass flow channel.

Abstract: A flow sensor system including a flow sensor assembly is provided. The sensor assembly may be configured to allow fluid flow through a flow conduit. A flow disrupter may be disposed in the flow conduit to impart disturbances to the fluid flow. A by-pass channel may be in fluid connection with the flow conduit and may be arranged to have a geometrical relationship relative to the flow conduit and the flow disrupter to affect flow characteristics in the bypass channel. One or more sensors may be disposed in the by-pass channel to generate a signal responsive to the flow characteristics in the bypass channel. In a first flow regime, the flow characteristics in the bypass channel may effect an amplitude response of the sensor, and in a second flow regime, the flow characteristics may effect a temporal response of the sensor.

Abstract: A flow rate measuring device includes a fluid resistance member through which measurement target fluid flows; an upstream side pressure sensor configured to measure pressure on an upstream side of the fluid resistance member from a change of electrical resistance of a resistive element attached to a pressure sensitive surface onto which the target fluid is introduced, and also to measure a temperature of the pressure sensitive surface from a temperature-dependent change of the electrical resistance of the resistive element; a temperature sensor to measure a temperature of the target fluid flowing through the fluid resistance member; and a flow rate calculation part that calculates a flow rate of the target fluid based on the pressure measured by the upstream side pressure sensor, pressure-flow rate characteristics of the fluid resistance member, the upstream side pressure sensor temperature, and the target fluid temperature in the fluid resistance member.

Abstract: An air flow measuring device includes a measured passage and a sensor portion. Measured air which is a measuring object flows through the measured passage. The sensor portion is disposed in a sensor arrangement portion of the measured passage and is configured to measure a flow rate of measured air flowing through the measured passage. The measured passage includes an upstream bent portion on an upstream side of the sensor arrangement portion in a flow direction of measured air. The upstream bent portion includes an upstream throttle that partly decreases a passage area of the measured passage.

Abstract: A first passage has a branch position where a second passage is branched from the first passage to move air along a reference vector. The second passage accommodates a thermal sensor. The first passage has a throttle at a downstream of the branch position. The throttle has a throttle wall surface having a normal vector directed inwardly. A width direction is perpendicular to both a flow direction of air in the throttle and the reference vector. The throttle wall surface has a specific region, in which the normal vector includes a vector component in the width direction, and an angle ? between the normal vector and the reference vector is in a range of 90 degrees<?<180 degrees.

Abstract: An air flow measuring device includes a housing, a sensor, and a projection portion. The housing defines a bypass flow passage through which taken-in intake air passes and which has an outlet that opens into an intake passage toward a downstream side of a mainstream of intake air. The sensor is accommodated in the bypass flow passage to produce an electrical signal as a result of heat transfer between the taken-in intake air and the sensor. The projection portion is provided on an outer wall of the housing on a downstream side of the outlet in the mainstream and extends outward of the housing. A projection-portion projected region and an outlet projected region, which are formed respectively by projecting the projection portion and the outlet perpendicularly onto a projection plane that is perpendicular to a direction of the mainstream, overlap with each other.

Abstract: This disclosure relates generally to flow sensors, and more particularly, to flow sensors that include a pressure related output signal. In one example, a flow sensor assembly may include a housing with an inlet flow port, an outlet flow port and a fluid channel extending therebetween, with a flow sensing element positioned in the housing and exposed to the fluid channel. A filter insert may be situated in the fluid channel, sometimes upstream of the flow sensor. When so configured, the flow sensor assembly may output a pressure or differential pressure based, at least in part, on a value of the flow rate through the fluid channel as sensed by the flow sensor.

Abstract: A thermal flow sensor is responsive only to a modulated component of the flow. At zero flow the modulated component disappears, except for an artifact caused by motion of the modulator. This artifact is minimized by reducing the extent of modulator motion and by sampling the modulated signal at a quiescent part of the modulator's operating cycle. This results in a thermal flow sensor with a very stable zero.

Abstract: A flow sensor assembly that may include features that help prevent moisture from reaching a sensor die of the flow sensor assembly. In some cases, such features may include a bypass channel that is configured to reverse the direction of the flow of fluid at least once upstream of the sensor die. In some cases, an encapsulant may cover one or more bond pads of the sensor die. In some cases, an output of the flow sensor assembly may be a raw sensor output signal produced by the one or more sensor elements of the sensor die, without significant processing of the raw sensor signal.

Abstract: Flow straightener for a flowmeter, in particular an ultrasonic metering device, which can be fitted into a flow pipe which is upstream of or in the flowmeter and through which the fluid to be measured flows with a main direction of flow (H), comprising a number of vanes (11, 12, 16, 17), which each have surfaces (13) that are parallel to one another and, in the fitted position, run parallel to the main direction of flow (H) of the fluid to be measured, the vanes (11, 12, 16, 17) being arranged in such a way that, in the fitted position, the flow cross section (Q) of the fluid-carrying flow pipe is subdivided into a number of partial cross sections (TQ1,2,3,4,5), at least some of the partial cross sections (TQ1,2,3,4,5) being of different sizes.

Abstract: A plate-shaped board is arranged so that fluid passages are respectively formed at a sensor-element mounting surface side of the plate-shaped board and at a backside surface side thereof being opposed to the sensor-element mounting surface side, a curved passage portion is provided which is located upstream of the plate-shaped board and changes its direction so as to form a curved line, and the curved passage portion has an outer-side wall surface including a sloping portion that slopes so that, of two edge portions of the outer-side wall surface in a direction perpendicular to board surfaces of the plate-shaped board, the edge portion located on a sidewall surface, facing the sensor-element mounting surface, of the curved passage portion is positioned closer to an inner wall surface of the curved passage portion than the edge portion located on a sidewall surface opposed to the first sidewall surface, along the sidewall surfaces.

Abstract: An apparatus for determining at least one parameter of a medium flowing in a main flow direction, in particular of an intake air mass of an internal combustion engine, is proposed. The apparatus has a plug-in part that is introducible into the flowing medium with a predetermined alignment with respect to the main flow direction, having at least one inlet opening and at least one outlet opening as well as at least one main channel connecting the two openings. Also provided is at least one measurement channel that branches off from the main channel, having at least one sensor element, received in the measurement channel, for determining the at least one parameter. At least one directing surface, which diverts the flow of the medium from the measurement channel, is provided before a branching point of the measurement channel from the main channel.

Abstract: A fluid flow sensing device can include a tapered fluid flow channel formed into a main channel defining a fluid flow tube as an alternate fluid flow path. A tapered fluid flow channel can bypass some fluid flow from the main fluid flow channel into the alternate fluid flow path and a flow sensor disposed within the alternate fluid flow path. The tapered flow channel is tapered in a direction of fluid flow toward the flow sensor to thereby reduce flow eddies and enable optimal sensing performance by fluid flow sensor. An upstream fluid flow channel and a downstream fluid flow channel can be molded into the main fluid flow channel, especially bypassed in the fluid flow path of the main fluid flow channel. A fluid flow sensor can be placed between the upstream fluid flow channel and the downstream fluid flow channel for measuring fluid flow rate the channel.

Abstract: An air flow measuring device has a throttle portion provided in a first sub-passage, a second sub-passage branched from the first sub-passage at an upstream side of the throttle portion, and a flow amount sensor located in the second sub-passage. The second sub-passage is configured to introduce therein a part of air flowing in the first sub-passage, and an inlet of the second sub-passage is open into the first sub-passage at one side in a first radial direction perpendicular to a flow direction of air flowing in the first sub-passage. Furthermore, the throttle portion is provided to gradually reduce a passage dimension of the first sub-passage in a second radial direction, as toward an outlet of the first sub-passage. Here, the second radial direction is perpendicular to a surface defined by the first radial direction and the flow direction of air in the first sub-passage.

Abstract: An air flow measuring instrument, comprising: an auxiliary passage 8 arranged inside a main passage through which fluid flows, a tabular member 5 on which a pattern of a heating resistor for measuring an air flow is provided on one face 5a, the tabular member being disposed inside the auxiliary passage so that the one face 5a on which the heating resistor pattern of the tabular member is provided is disposed along a flow of fluid inside the auxiliary passage 8, a heating resistor pattern-side fluid passage 8a portion formed so that the fluid flows between the face 5a and a passage-forming surface 8d of the auxiliary passage, and a back-surface 8b side fluid passage portion formed so that fluid flows between a face 5b on a side opposite to the face of the tabular member and the passage-forming surface of the auxiliary passage. Guidance portion 13 guiding dust that collides against the end portion to back-surface side fluid passage portion 8b side is provided on upstream-side end of tabular member.

Abstract: A multi-vortex flowmeter includes a vortex flowmeter for measurement by volume flow rate and a thermal flowmeter for measurement by mass flow rate to selectively use the two flowmeters according to the flow rate of fluid to be measured flowing through a flow channel. The multi-vortex flowmeter has a switching point between two flowmeters based on the mass flow rate. A mass flow rate Qm at the switching point in a range larger than the minimum flow rate of a vortex flowmeter and smaller than the maximum flow rate of a thermal flowmeter is determined by: Qm=K3*?P. Alternatively, a volume flow rate Q at the switching point in a range larger than the minimum flow rate of a vortex flowmeter and smaller than the maximum flow rate of a thermal flowmeter is determined by: Q=K1/?P.

Abstract: An improved flow measuring device, such as a mass flow meter or mass flow controller, providing a high turn-down ratio as compared to prior art devices. In accordance with various embodiments of the invention, a flow sensor includes a sensor flow path that includes one or more restrictions configured to provide the sensor flow path with a non-linear relationship between a pressure drop across the sensor flow path and the flow of fluid through the flow sensor conduit. Such a flow sensor preferably achieves a high turn-down ratio by way of a variable bypass ratio that is directly proportional to the sensor tube mass flow rate so that the turn-down ratio of the mass flow controller will be ideally proportional to the square of the turndown achievable by the flow sensor conduit fluid sensing portion alone. In some embodiments, the restriction can be employed as a part of a fluid seal having an orifice and disposed between a flow sensor portion of a flow meter and a bypass portion of the flow meter.

Abstract: A temperature-sensitive sensor (21) and a heating temperature-sensitive sensor (22) are fixed in position in a liquid-tight fashion by welding, with the metal tubular bodies (36 and 37) being inserted into the tubular body insertion holes (19 and 20) of a vortex detector (4). Sealing performance is secured without using any O-ring. The temperature-sensitive sensor (21) and the heating temperature-sensitive sensor (22) respectively have lead wires (42 and 43) held together with the lead wires (27) of a vortex detection sensor (11) within the internal space (35), and the lead wires (27, 42, and 43) thus held together are led out toward the flow rate converter (not shown) via a metal pipe (34). Since the lead wires (27, 42, and 43) are held together within the internal space (35) and led out toward the flow rate converter via the metal pipe (34), there is involved only one joint portion between the sensors and the flow rate converter. With this structure, explosion-proof performance can be attained easily.

Abstract: To provide a flowmeter producing stable measurement results and coincidentally achieving miniaturization, a bent portion is provided in a flow path located between an inlet port of fluids to the flowmeter and a second flow path at which a sensor detecting a flow rate is positioned, thus forming at a sensor an almost uniform flow-velocity distribution in cross-section of the fluids and a reproducible and constant flow-velocity distribution.

Abstract: A thermal type flow sensor includes a base portion provided along the direction of a fluid flowing through a main passage, and a sensor element mounted on the base portion and having an exothermic resistor formed on a substrate for detecting the fluid flow rate. The base portion has a rectangular recessed portion in which the sensor element is fixed so that the surface of the detecting portion of the sensor element is positioned lower than an upper edge of the recessed portion. A wall portion of the measuring passage facing the sensor element is constricted. The exothermic resistor is disposed along the fluid passage and spaced away from the upstream side upper edge of the recessed portion and cannot be substantially affected by a fluid flow disturbance due to a step portion formed between the upper edge of the recessed portion and the detecting portion surface.

Abstract: A thermal flow detecting apparatus detects fluid flow in a main flow passage. A bypass passage portion is provided through which some fluid bypasses the main flow passage. A detecting element is provided in the bypass passage portion and arranged at a location eccentrically displaced from the center of a cross section of the bypass passage portion. A throttle portion is provided upstream of the eccentric detecting element in the bypass passage portion for throttling the cross section partially on a side of the detecting element.

Abstract: The present invention provides an air flow measuring device comprising a housing with a sub-passage having a inlet and a outlet for air flow formed in the housing, the sub-passage further having a predefined curvature with a maximum downstream point and a flow measuring element located in the sub-passage at a position at least further downstream from the point.

Abstract: A flow sensor functions as a flow meter, for measuring the flow rate of a measurement objective fluid. The flow sensor comprises a flow passage, through which the measurement objective fluid flows, a sensor arranged so as to face the flow passage from a top wall that defines the flow passage, a throttle surface opposed to the top wall where the sensor is arranged, and an inclined surface provided on an upstream side of the throttle surface. The inclined surface is disposed such that the flow passage widens toward the inlet side of the flow passage. The inclined surface has an angle such that an extension line thereof passes through a position that is offset toward the upstream side, as compared to the detecting section of the sensor.

Abstract: An air flow rate measuring device is provided in which a pressure loss across a grid therein due to the load which is generated when a hose band is tightened is reduced and deterioration of its measurement accuracy due to the grid deformation is prevented. The grid is configured to have a grid portion which absorbs deformation at the outer periphery thereof, and another grid portion which does not absorb deformation at the inner periphery thereof. In order to make the grid portions independent of each other, the grid is provided with a frame, and the mesh grid inside of the frame which maintains a rectifying effect, prevents the deterioration of the measurement accuracy, and does not absorb deformation, and the grid outside of the frame absorbs deformation.

Abstract: The invention provides a thermal type flow meter which has a high reliability and a low cost. In a thermal type flow meter provided with a flow rate detecting element in which at least a heat generating resistor and a lead electrode are formed on a surface of a tabular substrate, and a support body in which a concave portion accommodating the flow rate detecting element is formed on a surface, and in which the flow rate detecting element is firmly fixed and accommodated by an adhesive agent in a back surface of the tabular substrate and a part of a bottom surface of the concave portion, an approximately straight discharge groove which is deeper than a bottom surface of the concave portion and passes through both end surfaces in upward and downward sides of the concave portion is formed from the upstream side of the support body concave portion to the downstream side, between the cavity of the tabular substrate and the back surface region of the tabular substrate in which the lead electrode is formed.