Abstract: A fluid flow rate and density measuring apparatus is disclosed including a section of cylindrical conduit comprising a measurement section or housing for the flow sensor. The flow sensor housing is fixedly attached to a conduit at its distal ends allowing fluid to pass through the open ends of the sensor housing as fluid flows through the conduit. An elongated, streamlined, cylindrically symmetric structure is located within the housing with its longitudinal axis aligned along that of the housing thereby forcing fluid through the annular gap between the exterior of the elongated cylindrical structure and the interior wall of the sensor housing.

Abstract: In a device for determining at least one parameter of a medium flowing in a main direction of flow in a line, which device has a part that can be inserted into the line with a predeterminable orientation in relation to the main direction of flow in such a manner that a partial stream of the medium flowing in the line passes into an entry region of a channel structure formed in the part, a measuring channel, provided with a measuring element for determining the at least one parameter, branching off from the entry region and the entry region having a separation zone which is separated from the measuring channel and has at least one separation aperture, which separation aperture opens into the line at a side wall of the part, which side wall extends substantially parallel to the main direction of flow, the part advantageously has at least one wind shield which is disposed downstream of the at least one separation aperture in the direction of the main direction of flow and which projects from the side wall provid

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: Devices for determining at least one parameter of a medium flowing in a conduit, in particular for determining the air-mass flow in the intake tract of an internal combustion engine, including a conduit member and sensor device having a bypass section are already known. To prevent flow detachment at the side walls of the bypass section, it is proposed that a flow guide wall running substantially parallel to the side wall provided with the separation opening of the bypass section be arranged in the conduit member behind the separation opening, as viewed in the main flow direction; the length dimension b of the flow guide wall, as viewed in the main flow direction, being equal to or greater than the distance a of the separation opening from the rear wall; and the distance c of the flow guide wall from the center axis of the conduit member being greater than or equal to the distance d of the side wall provided with the separation opening of the bypass section from the center axis.

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.

Abstract: A dual function flow measurement apparatus is provided that combines the functionality of an apparatus that measures the speed of sound propagating through a fluid flowing within a pipe, and measures pressures disturbances (e.g. vortical disturbances or eddies) moving with a fluid to determine respective parameters of the flow propagating through a pipe. The apparatus includes a sensing device that includes an array of pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine desired parameters. The measurement apparatus includes a processing unit the processes serially or in parallel the pressure signals provided by the sensing array to provide output signals indicative of a parameter of the fluid flow relating to the velocity of the flow and the speed of sound propagating through the flow, respectively.

Abstract: A mass flow meter has a range of flow rate measurement that can be enlarged by changing of the structure of a sensor portion without modification of a bypass portion. The mass flow meter includes a sensor tube 5 through which fluid is transmitted while being heated, the flow meter being adapted to detect a mass flow rate of the fluid, based on a change in temperature distribution in the narrow sensor tube 5 that occurs according to the mass flow rate of the fluid, the flow meter comprising a flow restriction channel 7 for the fluid that is disposed in series with the narrow sensor tube 5.

Abstract: A device for determining at least one parameter of a medium flowing in a line, in particular for determining the air mass flow rate in the intake manifold of an internal combustion engine, which include a line component 3 and a sensor device 1 having a bypass part 6, are known. To prevent separation of the flow at the sidewalls of the bypass part, it is provided that a flow diversion element 2 be positioned in the line component 3 upstream from the bypass part 6 with respect to the main flow direction 18 and have at least one diversion surface 20 facing the main flow direction 18, which, starting from an apex line 25 located at a distance from the bypass part 6, curves evenly on both sides toward the two sidewalls 16, 17 so that the ends 38 of the diversion surface 20 facing away from the apex line are aligned with the sidewalls 16, 17.

Abstract: A configurable multi-function flow measurement apparatus is provided that can selectably function to measure the speed of sound propagating through a fluid flowing within a pipe and/or to measure pressures disturbances (e.g. vortical disturbances or eddies) moving with a fluid to determine respective parameters of the flow propagating through a pipe and detects the health of an industrial process. The configurable flow measurement device can also be selectable to function as a system diagnostic meter that provides a diagnostic signal indicative of the health of the industrial process, namely health of pumps, valves, motors and other devices in an industrial flow loop. The apparatus includes a sensing device that includes an array of strained-based or pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine desired parameters. In response to a remote or local configuration signal, a control logic selects the desired function of the flow measurement apparatus.

Abstract: A device is provided for determining at least one parameter of a medium flowing in a line in a main flow direction, e.g., a parameter of the intake air mass of an internal combustion engine. The device includes a part, which is inserted into the line at a predetermined alignment with respect to the main flow direction in such a way that a partial flow of the medium flowing in the line in the main flow direction flows through at least one measuring channel provided in the part in a first direction from an intake of the measuring channel to an outlet of the measuring channel. The device further includes a measuring element situated in the measuring channel for determining the at least one parameter.

Abstract: A gas flow sensor system, and method for gas flow rate measurement and self-calibration to overcome problems caused by degradation. Gas flow rate is accurately measured by determining the power dissipated at a constant differential temperature of a gas flow sensor, under conditions where its power dissipation is independent of its resistance. The gas flow sensor is adjusted to a predefined differential temperature compared to the temperature of the gas. In addition, variations in heat transfer coefficient (h) of a gas flow sensor are corrected by self-calibration of the gas flow sensor system. Experimentally established correction factors are applied to the gas flow sensor, to compensate for changes in its heat transfer coefficient (h) caused by degradation of the gas flow sensor. This offsets the adverse effects of use and aging of the gas flow sensor, thus reducing errors in gas flow measurement.

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: 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 sensor and carrier device are provided in combination with a pipeline for either placing a sensor element within the flow stream of the pipeline or a device to divert flow outside of the pipeline to measure a parameter of the conditions within the pipeline or of the gas flowing through the pipeline. The configuration of the probe comprising the carrier and sensor is such as to reduce the possibility of structural failure of the probe.

Abstract: Devices are previously known for determining at least one parameter of a medium flowing in a conduit, in particular for determining the air mass flow in the intake section of an internal combustion engine, having a conduit part and a sensor device that has a bypass part. In order to avoid a flow detachment at the side walls of the bypass part, it is provided that a flow vane, running at least approximately parallel to a side wall, provided with a separation opening, of the bypass part, be provided in a conduit part behind a separation opening, seen in the main flow direction, and that the conduit part be provided, in the area of the bypass part, with at least one projection that protrudes from an inner wall of the conduit part towards the bypass part.

Abstract: A device for measuring the volume flow or other substance properties of a gas, whose direction of flow can reverse. The arrangement contains a specially designed Y-piece, which is used for branching into direction-dependent flow paths and can be used at the same time for the measurement. Such devices can be preferably used in the area of mechanical respiration.

Abstract: A dual function flow measurement apparatus is provided that combines the functionality of an apparatus that measures the speed of sound propagating through a fluid flowing within a pipe, and measures pressures disturbances (e.g. vortical disturbances or eddies) moving with a fluid to determine respective parameters of the flow propagating through a pipe. The apparatus includes a sensing device that includes an array of pressure sensors used to measure the acoustic and convective pressure variations in the flow to determine desired parameters. The measurement apparatus includes a processing unit the processes serially or in parallel the pressure signals provided by the sensing array to provide output signals indicative of a parameter of the fluid flow relating to the velocity of the flow and the speed of sound propagating through the flow, respectively.

Abstract: A sensing apparatus for use in a mass flow rate sensor for measuring a fluid flow rate includes a main conduit for containing a fluid flow, and a sensor passageway for tapping a portion of the fluid flow from the main conduit at a first location, and returning the portion of the fluid flow to the conduit at a second location. At least one bypass passageway, which may be provided in the form of a tube, is positioned in the main conduit between the first and second locations, and the bypass passageway is provided with non-negligible entrance effects that are substantially equal to entrance effects of the sensor passageway, so that a bypass ratio of the apparatus remains constant. A mass flow rate sensor of the present disclosure accurately measures any type of gas but only requires calibration in only one reference gas.

Abstract: The present invention provides an air flow measuring device comprising a housing with a sub-passage having an inlet and an 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 system for measuring air flow rate in a duct includes an air flow sensor and an air flow conditioning device for collecting and accelerating a portion of the total air stream to the sensor, which may be means as known in the art. The conditioning device includes two opposed converging walls defining a nozzle, preferably a venturi, the sensor being disposed in the throat of the nozzle. The surfaces of the venturi walls are textured to trip the boundary layer near the wall surface into turbulence to maintain attachment of flowing air to the walls even when the angle of attack of the air is significantly non-axial. The wall texturing may be random or may be an organized pattern. A further embodiment includes a second flow conditioner/sensor in parallel with the first whereby an averaged flow measurement is taken for a more accurate reading.

Abstract: The flow of a fluid at low flow rates is measured in a flow sensing assembly and controlled without introducing measuring devices into the fluid flow path. The flow sensing assembly is enclosed in a housing to lessen ambient and fluid temperature change effects on the measurements obtained. As the fluid is flowing through tubing in the flow sensing assembly, the tubing is heated to impart heat to the fluid. Heat sensors are attached at spaced positions from each other along the tubing in the direction of fluid flow to sense temperatures. The amount of heat applied to the tubing is controlled to maintain an established temperature differential between the heat sensors. The amount of heat applied is measured to provide an accurate and proportional indication of the fluid flow rate.

Abstract: A mass flow rate sensor uses a Reynolds number correction function to compensate for errors in a bypass ratio of the sensor for all gases, based on the fact that all bypass errors are functions of Reynolds number. The sensor includes a sensor tube and a bypass tube dividing flow, wherein a bypass ratio of the sensor equals a total flow rate through the sensor divided by a flow rate through just the sensor tube. Heater elements heat an upstream portion and a downstream portion of the sensor tube, and a circuit is connected to the heater elements for producing a voltage based upon a difference in resistance between the heater elements. The voltage is calibrated based on known flow rates of a reference gas, and the flow rate through the sensor is based upon the calibrated voltage multiplied by a multi-gas correction function and a Reynolds number correction function.

Abstract: A flow direction detector is provided which includes a flow disruptor positioned in a fluid flow path to effect a detectable differential flow characteristic to such flow path based on fluid flow direction, and a sensor arrangement configured to detect such detectable differential flow characteristic within the flow path.

Abstract: A system to measure fluid flow characteristics in a pipeline, meter, and methods includes a pipeline having a passageway to transport flowing fluid therethrough, a process density meter including at least portions thereof positioned within the pipeline to provide flowing fluid characteristics including volumetric flow rate, fluid density, and mass flow rate of the flowing fluid, and a fluid characteristic display to display the fluid characteristics. The process density meter includes a vortex-shedding body positioned within the pipeline to form vortices and a vortex meter having a vortex frequency sensor to measure the frequency of the vortices and to determine the volumetric flow rate. The process density meter further includes a differential pressure meter positioned adjacent the vortex-shedding body to produce a differential pressure meter flow rate signal indicative of the density of fluid when flowing through the pipeline.

Abstract: A spacer has an annular concave portion, at one end face, to accept a rectifier that rectifies fluid flowing through a flow channel in a flowmeter, a protruding annular convex portion, at the other end face, of a size to fit in the annular concave portion, and fixing means, on an outer surface, for fixing the spacer to a tube of the flow channel through engagement. A rectifier unit is temporarily assembled by integrating the spacer and the rectifier that are provided alternately in series in an axial direction into a tubular unit. It is thus possible to achieve efficient assembly, by which plural rectifiers are inserted and attached inside the tube through a single insertion operation. Moreover, it is possible to address a need for a reduction of rectifiers in size or a change to the specifications regarding the number of rectifiers to be provided.

Abstract: The invention relates to a device with an air inlet manifold (1) and an air mass sensor arrangement (2) inserted radially therein, the insertion opening (3) of which is arranged perpendicular to the airflow direction (6) in the manifold (1). A wing-shaped shielding body (7) is arranged before the insertion opening (3) such as to cover the insertion opening (3) and guarantee a streamline airflow to the insertion opening (3) and the essentially straight surface thereof, transverse to the flow direction of the air flowing over said surface, is oriented perpendicular to the insertion direction of the air mass sensor arrangement (2).

Abstract: An airflow meter has a membrane type sensor element. The sensor element is supported on a support member so that a sensing surface of the sensor element is in parallel to the airflow direction. The airflow meter has at least one means for protecting the sensor element from dust such as foreign particles. The protecting means is provided with an obstruction member that is disposed upstream or downstream of the sensor element with respect to the airflow direction. The sensor element is hidden behind the obstruction member. The obstruction member has gradually spreading surfaces and gradually converging surfaces along the airflow direction. Alternatively, the protecting means can be provided with a deflector, a cover member, a flow guide member, an inlet or a dust collector.

Abstract: The present invention relates to a thermal flowmeter capable of sensing a flow rate in either direction, having a linear output characteristic, and producing a stable output without impairing the response characteristic. In the thermal flowmeter, a laminate is fitted in a channel space formed in a body, forming a main channel. The laminate includes a mesh sheet so that a mesh portion is provided between the main channel and a sensor channel. A measurement chip is provided with an upstream temperature sensing resistor, a downstream temperature sensing resistor, a heating resistor, and a fluid temperature sensing resistor. By an electric circuit, the heating resistor and the fluid temperature sensing resistor are controlled to provide a constant temperature difference. Accordingly, the flow rate of a fluid under measurement is measured based on a temperature difference between the upstream and downstream temperature sensing resistors.

Abstract: The present invention involves an air induction system for inducing ambient air to a vehicle engine. The system comprises an air filter for filtering the ambient air, a clean air duct, a sensor, and a flow conditioning device. The clean air duct is in fluid communication with the air filter and has first and second ends. The first end is connected to the air filter. The sensor is mounted adjacent the second end of the duct. The sensor is configured to receive the ambient air. The flow conditioning device is mounted in the clean air duct and includes an outer body having an air inlet end and an air outlet end. The flow conditioning device has a configuration of connected inner walls disposed within the body and spaced apart from each other by radially increasing intervals from the center of the configuration.

Abstract: A sensing apparatus for use in a mass flow rate sensor for measuring a fluid flow rate includes a main conduit for containing a fluid flow, and a capillary tube for tapping a portion of the fluid flow from the main conduit at a first location, and returning the portion of the fluid flow to the conduit at a second location. The capillary tube is disposed about a centerline, and includes an inner wall defined by an inside radius measured from the centerline. The inside radius varies periodically, preferably sinusoidally, along the centerline for at least a portion of the capillary tube, thereby forming a turbulated surface on the inner wall. The turbulated inner wall increases wall surface area, and fluid mixing. The resulting increased heat transfer rate decreases the error in sensor output from nonlinear behavior.

Abstract: A laminated filter is fit in a passage space formed in a body. The laminated filter is made of a mesh plate including a mesh part, a first blocking plate including a blocking part, a second blocking plate including a blocking part, and a third blocking plate including a blocking part which are arbitrarily combined and layered. Accordingly, a three-layered mesh part is placed between a main passage and a sensor passage and a blocking wall is constructed of the three blocking parts.

Abstract: A flow direction detector is provided which includes a flow disruptor positioned in a fluid flow path to effect a detectable differential flow characteristic to such flow path based on fluid flow direction, and a sensor arrangement configured to detect such detectable differential flow characteristic within the flow path.

Abstract: The present invention relates to a mass flow controller for a control purge and a managing method of the same. When a user sets the mode to a control purge mode capable of controlling a maximum flowing amount for constantly maintaining a maximum flowing amount when performing a purge function after the user sets a purge function mode based on a purpose of use of a mass flow controller, a control circuit compares a set value of a flowing amount inputted based on a user's selection with a previously set threshold value and controls a valve for constantly maintaining a maximum flowing amount by switching to a gain resistor for a purge mode having a gain value capable of performing a purge function and controls a valve for thereby accurately controlling a small flowing amount by switching to a gain resistor for a common control mode having a gain value capable of performing a common control function.

Abstract: A spacer has an annular concave portion, at one end face, to accept a rectifier that rectifies fluid flowing through a flow channel in a flowmeter, a protruding annular convex portion, at the other end face, of a size to fit in the annular concave portion, and fixing means, on an outer surface, for fixing the spacer to a tube of the flow channel through engagement. A rectifier unit is temporarily assembled by integrating the spacer and the rectifier that are provided alternately in series in an axial direction into a tubular unit. It is thus possible to achieve efficient assembly, by which plural rectifiers are inserted and attached inside the tube through a single insertion operation. Moreover, it is possible to address a need for a reduction of rectifiers in size or a change to the specifications regarding the number of rectifiers to be provided.

Abstract: An airflow meter has a member that defines a bypass passage. The bypass passage has a sensing passage in which a sensor tip is disposed. The sensing passage is restricted in at least a lateral direction that is a direction perpendicular to both a longitudinal direction of the sensing passage and a perpendicular direction perpendicular to the surface of the sensor tip. This arrangement defines relatively wider distance in the perpendicular direction on the sensor tip.

Abstract: A waste-material entry prevention member arranged upstream of a flow sensor is a rod- or plate-like member protruding halfway across the cross-section of a flow passage. Hence, vortexes or energy of the vortexes produced in fluid flowing by the waste-material entry prevention member is diffused by a stream of the fluid passing through a space left between the waste-material entry prevention member and the wall surface of the flow passage which the waste-material entry prevention member faces. Thus, production of vortexes is held down. Further, by making the flow sensor generate heat or heating the flow sensor, thermophoresis of the fluid is caused near the surface of the flow sensor. By this, particles contained in the fluid are prevented from accumulating on the flow sensor.

Abstract: A laminated filter is fit in a passage space formed in a body. The laminated filter is made of a mesh plate including a mesh part, a first blocking plate including a blocking part, a second blocking plate including a blocking part, and a third blocking plate including a blocking part which are arbitrarily combined and layered. Accordingly, a three-layered mesh part is placed between a main passage and a sensor passage and a blocking wall is constructed of the three blocking parts.

Abstract: A device for measuring the flow of a fluid has a primary duct and a bypass arranged in series to the primary duct. The bypass has a first section and a second section. A baffle plate with a hole for the passage of the fluid is arranged in the first section. The second section comprises two parallel secondary ducts. In the first section, a turbulent flow dominates, while the flow in the second section is primarily laminar. If the turbulent effects in the bypass are sufficiently strong, the ratio of the flows in the primary duct and the bypass can be substantially independent of the fluid properties and of the flow rate. By using two parallel secondary ducts in the second section, high flow rates and therefore strongly turbulent effects can be achieved without exceeding the measuring range of the sensor.

Abstract: A flow sensor includes a mounting plate, bending plate, and a sensing assembly. The mounting plate is mounted to an internal surface of an air hose. The mounting plate is flexibly coupled to the bending plate, which is displaced in response to the flow of gas. The sensing assembly is positioned on the bending plate and includes a temperature sensor for sensing relatively lower flow rates during a thermal mode, and one or more displacement sensors for sensing relatively higher flow rates during a displacement mode. The temperature sensor outputs a thermal mode signal and the displacement sensors output a displacement mode signal. A flow sensing system includes the flow sensor, processor, memory, and a computer. The processor is responsive to the thermal and displacement mode signals. The computer is coupled to the processor and controls calibration of the flow sensor.

Abstract: The present invention relates to a mass flow controller for a control purge and a managing method of the same. When a user sets the mode to a control purge mode capable of controlling a maximum flowing amount for constantly maintaining a maximum flowing amount when performing a purge function after the user sets a purge function mode based on a purpose of use of a mass flow controller, a control circuit compares a set value of a flowing amount inputted based on a user's selection with a previously set threshold value and controls a valve for constantly maintaining a maximum flowing amount by switching to a gain resistor for a purge mode having a gain value capable of performing a purge function and controls a valve for thereby accurately controlling a small flowing amount by switching to a gain resistor for a common control mode having a gain value capable of performing a common control function.

Abstract: The flow of a fluid at low flow rates is measured and controlled without introducing measuring devices into the fluid flow path. As the fluid is flowing through tubing, the tubing is heated to impart heat to the fluid. Heat sensors are attached at spaced positions from each other along the tubing in the direction of fluid flow to sense temperatures. The amount of heat applied to the tubing is controlled to maintain an established temperature differential between the heat sensors. The amount of heat applied is measured to provide an accurate and proportional indication of the fluid flow rate.

Abstract: To measure the flow rate of coolant through a cooling hole of a film-cooled part, a transient thermal response of an external surface temperature of the film-cooled part is measured and the transient thermal response is characterized mathematically. From the mathematical characterization, the flow rate through the film hole is determined.

Abstract: A mass flow controller is disclosed and includes body portion having a first internal passage and at least second internal passage formed therein, a flow control valve coupled to the body portion and in communication with the first and second internal passages, at least one pressure transducer coupled to the body portion and in communication with at least one of the first internal passage, the second internal passage, and the flow restrictor, a nonlinear flow restrictor configured to produce a high compressible laminar flow therethrough coupled to the second internal passage, a thermal sensor in communication with at least one of the first internal passage, the second internal passage, and the flow restrictor, and an exhaust vessel in communication with the flow restrictor.

Abstract: A device for measuring at least one parameter, in particular of a volumetric flow, of a medium flowing in a line, in particular of the intake air volumetric flow of an internal combustion engine, includes at least one measuring element around which the medium flows. Constrictions, which do not uniformly constrict the cross-section of the line, do not produce any ring-shaped eddies that may be heard in the form of whistling noises.

Abstract: Known devices for measuring the mass of a flowing medium can be impaired in their measurement precision by fluid components carried along in the medium. The device according to the invention has a ricochet body, which is disposed upstream of the measuring element and is at least partially encompassed by an outer ring, where the outer ring constitutes a section inside the outer ring that tapers in the flow direction in order to deflect fluid components, which are carried along in the flow, away from the measuring element by means of the ricochet body. The device is useful for measuring the mass of a flowing medium, in particular for measuring the intake air mass of internal combustion engines.

Abstract: A device for measuring at least one parameter of a medium flowing in a line, in particular the intake air mass of an internal combustion engine in which fluid particles and solid particles in the line influence a characteristic curve behavior of a measuring element which is used to determine a parameter of the flowing medium. A protective screen according to the invention deflects fluids and solid particles away from the measuring element in such a way that they are conveyed against an inner wall of the line. In addition, the device stabilizes the flowing medium by generating longitudinal eddies in a flow direction.

Abstract: The flow of a fluid at low flow rates is measured and controlled without introducing measuring devices into the fluid flow path. As the fluid is flowing through tubing, the tubing is heated to impart heat to the fluid. Heat sensors are attached at spaced positions from each other along the tubing in the direction of fluid flow to sense temperatures. The amount of heat applied to the tubing is controlled to maintain an established temperature differential between the heat sensors. The amount of heat applied is measured to provide an accurate and proportional indication of the fluid flow rate.

Abstract: An integrated module is provided for measuring a flow rate of a fluid, whether gaseous or liquid, with a flow restrictor comprising a plurality of orifices adapted to a flow channel of the integrated module and a sensor mounted to measure a property of the fluid at said flow restrictor corresponding to the flow rate. The integrated module provided may be used in numerous flow systems, such as reactors, ventilators and respirators, and has the benefit of better laminarization of the flow as well as better calibration between the flow sensor and the flow restrictor for more accurate flow measurements.

Abstract: A split-flow-type flowmeter includes a detection element 2 disposed to face a flow path thereof and a venturi structure 4 formed within a flow path 1 in the vicinity of the detection element 2 and adapted to throttle a flow directed toward the detection element 2 to thereby reduce disturbance of the flow. The venturi structure 4 is disposed in opposition to the detection element 2 within the flow path 1 and includes a protrusion 5 protruding toward the detection element 2 within the flow path 1 of the split-flow-type flowmeter.

Abstract: In devices for measuring the mass of aspirated air of an internal combustion engine, for instance, via a line, it is already known to provide a tubular body inside this line and to provide a temperature-dependent measuring element inside the tubular body. In order that dirt particles and liquid droplets entrained by the aspirated air will be kept away from the measuring element, in accordance with the invention, a protective screen is disposed inside the tubular body, upstream of the measuring element; the screen extends in inclined fashion in the flow direction, and dirt particles and liquid droplets are deposited on it and carried to a downstream end of the protective screen, so that via an outflow opening they can reach the inner conduit wall of the tubular body and be made to bypass the measuring element.