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: An integrated sensor for automated systems includes a flow sensor, a temperature sensor, and a network interface. In a particular embodiment of the invention, the flow sensor includes a temperature sensor (26) which determines the temperature of the fluid flowing in a flow path (12). A heater (18) is coupled to the flow path, and is energized by a controller (20) with sufficient electrical power to raise the temperature of the heater above the measured fluid temperature by a fixed temperature difference. In order to aid in determining the temperature difference, a sensor (24) may be associated with the heater (18). The amount of power required to maintain the temperature difference is a measure of the flow velocity. The volumetric flow rate is the product of the flow velocity multiplied by the area of the flow sensor. The mass flow rate is the product of the volumetric flow rate multiplied by the mass density of the fluid.

Abstract: A flow-rate detecting device for a heat-sensitive type flow sensor having high reliability. The device includes a planar substrate having first and second through-holes formed therein in juxtaposition with each other, an insulative supporting film formed over one major surface of the substrate so as to cover the through-holes, a fluid temperature measuring resistor formed by a heat-sensitive resistor film deposited at a location of the first through-hole on the supporting film oppositely to the substrate, a heat generating resistor formed of a heat-sensitive resistance film deposited at a location of the second through-hole on the supporting film oppositely to the substrate, an insulative protection film deposited so as to cover the fluid temperature measuring resistor and the heat generating resistor, and a reinforcing film provided for the fluid temperature measuring resistor. The reinforcing film is not provided for the heat generating resistor.

Abstract: To obtain a flow sensor having excellent responsibility, sensitivity and reliability and high flow detection accuracy by suppressing the deformation of a diaphragm, first additional patterns are formed on a side opposite to connection patterns of a heating element so that thin film patterns formed on the diaphragm become almost symmetrical, thereby suppressing the deformation of the diaphragm caused by internal stress between a base film or protective film and a platinum film forming the thin film patterns and the differences of mechanical or thermal properties therebetween.

Abstract: A heat-sensitive flow rate sensor that is high in productivity, superior in accuracy of flow rate measurement and sensitivity. A bottom face of a concave accommodating portion 18 of an supporting member 16 is provided with an adhesion face 24 for fastening a flow rate-detecting element 14 thereon with an adhesive 15, installation faces 25a, 25b for holding the flow rate-detecting element 14 thereon, and a protruding face 26 for blocking in a raised manner the whole area of a cavity 13 on the underside of the flow rate-detecting element 14. As a result of employing this construction, even when increasing an intake fluid to a large amount of flow, the protruding face 26 blocks the vicinity of the cavity 13. Therefore, the fluid to be measured hardly flows into the gap between the underside of the flow rate-detecting element 14 and the supporting member 16. Consequently, accuracy in flow rate measurement is improved.

Abstract: In a sensor chip for a fluid flow sensor, a thin film portion is formed above a hollow cavity portion while leaving thin film layers formed on the surface of a substrate. A conductor is provided on the inner wall face of a through hole formed to penetrate the substrate to thereby electrically connect a detecting portion constituted by a conductor film in the thin film layers and a substrate conductor portion formed on the rear face side of the through hole. The surface of a circuit board is formed with a control circuit and a base conductor portion electrically connected to the control circuit. The sensor chip and the circuit board are layered and the substrate conductor portion and the base conductor portion are electrically connected.

Abstract: A flow sensor component consists of a diaphragm of monocrystalline silicon, the diaphragm having arranged therein filled slots which are filled with a thermally insulating material and which penetrate the diaphragm from a first main surface to a second main surface thereof. The filled slots defining at least one heating area of the diaphragm provided with at least one heating element and at least one detection area of the diaphragm provided with at least one temperature detection element, the filled slots thermally insulating the heating area and the detection area from one another and surrounding the heating area and the detection area completely.

Abstract: An airflow sensor including a micro-heater having a film structure, which can reduce a warpage of the film structure even when a thick ness of the film structure to improve a mechanical strength thereof. An airflow sensor is provided with a monocrystalline silicon substrate having a hollow portion therein; a thin film heater portion as a micro-heater arranged above the hollow portion; and a temperature sensor. The thin film heater portion has a laminated structure of a lower thin film, a heater layer, and an upper thin film. The lower and the upper thin film respectively have a tensile stress film and a compressive stress film laminated with the tensile stress film, and are symmetry laminated with respect to the heater layer. The tensile stress film is made up of a Si3N4 film having a great moisture-proof characteristic; and the compressive stress film is made up of a SiO2 film having a great adhesion.

Abstract: In a flow sensor, a heater is provided in the middle of an insulation thin film stretched above a gap on a substrate. Temperature measuring elements, which in some embodiments are thermopiles, are provided on both sides of the same, and an ambient temperature measuring resistive element is provided on the top surface of the silicon substrate. The thermopiles in some embodiments are made of polysilicon and aluminum, and in some embodiments the polysilicon is doped with phosphorus (P). In some embodiments, the amount of phosphorus is determined such that temperature characteristics of the thermopiles and have an absolute value substantially equal to that of temperature characteristics attributable to factors other than the thermopiles and have a (positive or negative) sign opposite to that of the latter. Thus, the temperature characteristics of the thermopiles cancel the temperature characteristics attributable to factors other than the thermopiles.

Abstract: A flow sensor for determining the velocity and direction of a fluid flow including a substrate, a heat source located on the substrate, and a first and a second heat sensor located on the substrate to detect at least a portion of heat generated by the heat source. The first and second heat sensors and the heat source are arranged in a non-linear orientation.

Abstract: A microflow sensor element for obtaining a response quickly with high response sensitivity regardless of the direction of an air flow. A pyroelectric detection unit is provided on a substrate, the pyroelectric detection unit having an upper and a lower electrode which are respectively provided on the surface and undersurface of a ferroelectric thin film. A heater portion whose temperature is modulated periodically as designated is provided on the upper electrode via a thin film of insulating material.

Abstract: A heater for a gas sensor has a first thermistor element and a second thermistor element arranged in an electrically parallel configuration. Each thermistor element may be deposited onto a substrate such that the first thermistor element extends about a perimeter of the substrate and the second thermistor element extends across a portion of the substrate intermediate the perimeter of the substrate. The thermistor elements are preferably fabricated of materials having differing thermal coefficients of resistivity. A method of heating the gas sensor includes disposing the two thermistor elements in an electrically parallel configuration over a surface of the substrate and passing an electric current through the elements.

Abstract: A flowmeter includes a heating resistor and a resistive element for detecting the temperature of the heating resistor. The heating resistor is controlled so that the temperature detected by the resistive element approaches a reference temperature determined based on the temperature of the fluid flow. As a result, the temperature of the upstream side of the heating resistor becomes lower than the reference temperature, while the temperature of the downstream side of the heating resistor becomes higher than the reference temperature. Another resistive element is arranged on the upstream side or the downstream side of the heating resistor for detecting the rate of the fluid flow, and the rate and the direction of the fluid flow are detected by comparing the temperature of the resistive element with the reference temperature. This flowmeter is immune to variation in the resistance of the heating resistor.

Abstract: A thermo-sensitive flow rate sensor that has a flow rate detecting device, in which a heating element constituted by thermo-sensitive resistor film, is formed on a top surface of a plate-like substrate and in which a diaphragm is formed by partially removing the plate-like substrate. This sensor further has a supporting element arranged in such a way as to have a top surface that is parallel to the direction of flow of a fluid to be measured. The flow rate detecting device is supported and fixed in a recess portion formed in the supporting element so that the top surface of the device is nearly flush with the top surface of the supporting element. Further, the thin-plate-like member is attached to the back surface of the flow rate detecting device in such a way as to close a cavity.

Abstract: The invention relates to a device for measuring pressure, temperature and flow velocity. It comprises a sensor (6) with a sensor support body (13) provided with a diaphragm (15) covering a cavity (14) formed in said support body (13). A pressure sensitive element (41) is mounted on said diaphragm, for recording pressure. Furthermore, a temperature sensitive resistor (42) mounted in the vicinity of and having known temperature dependences, for recording temperature. It also comprises an electrical circuit (43, 44, 45, 46) selectively outputting signals from either of said pressure sensitive element and said temperature sensitive resistor.

Abstract: A heat-sensitive flow rate sensor that is high in productivity, superior in accuracy of flow rate measurement and sensitivity. A bottom face of a concave accommodating portion 18 of an supporting member 16 is provided with an adhesion face 24 for fastening a flow rate-detecting element 14 thereon with an adhesive 15, installation faces 25a, 25b for holding the flow rate-detecting element 14 thereon, and a protruding face 26 for blocking in a raised manner the whole area of a cavity 13 on the underside of the flow rate-detecting element 14. As a result of employing this construction, even when increasing an intake fluid to a large amount of flow, the protruding face 26 blocks the vicinity of the cavity 13. Therefore, the fluid to be measured hardly flows into the gap between the underside of the flow rate-detecting element 14 and the supporting member 16. Consequently, accuracy in flow rate measurement is improved.

Abstract: A micromachined thermal flowmeter comprises characteristically at least one crystal silicon island jutted into the flow of a fluid to be determined which are embedded in an elastic low thermal conductivity layer supported by a rigid low thermal conductivity plate having a heating element and a pair of thermal sensing elements formed therein.

Abstract: The invention relates to a device for measuring the flow of a medium e.g., a gaseous medium or a fluid medium, which device is based on measuring and affecting the temperature distribution of a medium flowing along, which flow sensor comprises two object, each comprising a heating element and a temperature sensor, the measured temperature difference being kept, by way of a control loop, to the value of zero, the asymmetry of the power supply to the objects in order to comply with the aforesaid criterion, according to which the temperature difference must be zero, being representative of the value to be measured of the medium flow, taking into account parameters associated with the medium, such as its density and specific heat.

Abstract: Disclosed is a thermal air flow sensor in which polycrystalline silicon is used as a heat generating resistor, and which has improved detection sensitivity. An upstream heat generating resistor, a downstream heat generating resistor, a temperature measuring resistor, and an air temperature measuring resistor are formed on a silicon substrate. These resistors are each formed of a semiconductor thin film in which polycrystalline silicon is mixed with a silicide compound and which contains an impurity doped therein. The formed resistor has small specific resistance and a large resistance temperature coefficient.

Abstract: The sensor (7) for a mass flow meter (1) including a capillary tube (6) for circulation of fluid in parallel with the principal circuit of the fluid circulation. The sensor includes heating mechanisms (20) of the capillary tube (6) and mechanisms for measuring the temperature (22, 23), upstream and downstream from this heating mechanism (20), and separate from the heating mechanism. The mechanisms for measuring the temperature (22, 23) are two resistors manufactured by deposition in an external manner on the sensor tube (6), one of them (22) upstream from the heating mechanism (20), the other (23) downstream from the heating mechanism. The manufacturing process includes stages of deposition by an electron gun, firstly of a layer of zirconia (21) of several microns, on the tube (6) made of stainless steel, then of the sensitive components (27) and the contacts (31, 32) of the measurement resistors (22, 23), made of platinum, and defined by masks of nickel.

Abstract: The object of this invention is to provide a heated type air flow rate sensor for measuring an air flow rate using heat generating resistive element or resistor formed within a diaphragm of which periphery is fixed, in which diaphragm destruction due to the collusion of dust is adapted to be prevented.

Abstract: A thermal type air flow sensor which corrects variation of characteristics of a thermal type air flow sensor due to adherence or deposition of fouling contained in an intake air for maintaining an initial accuracy. An air flow rate is measured by means of a heating resistor and a temperature measuring resistor formed by semiconductor fine patterning. A part of the semiconductor substrate is removed. The heating resistor and a portion of the temperature measuring resistor are formed above a space defined by removing the semiconductor substrate. A voltage of the portion of the temperature measuring resistor located above the space is detected for correcting an error in measurement of an intake air using the voltage detected.

Abstract: A thermo-sensitive flow rate sensor that comprises a plate-like substrate, a part of which is removed so that a space is provided therein, a diaphragm portion formed like a thin layer above the space in such a manner as to be integral with the plate-like substrate, and a heating element constituted by a thermo-sensitive electrically resistant film formed on the diaphragm. Plural holes penetrating the diaphragm portion are bored in an outer peripheral portion of the heating element. Each of the plurality of holes is shaped in such a way as to have obtuse corner portions or to have substantially no corner portions. The thermo-sensitive flow rate sensor measures the flow rate of a fluid, which is to be measured, according to an amount of heat transferred to the fluid from a part heated by energizing the heating element.

Abstract: A heat generation type flow sensor of an enhanced output sensitivity which is destined for use, for example, as an air flow sensor employed in an engine control system of a motor vehicle.

Abstract: A measurement device for measuring the mass of a medium flowing along a flow direction, in particular the intake air mass of an internal combustion engine, has a plate-shaped sensor element, which is inserted into a recess of a sensor support. The sensor element includes a membrane that supports a measuring element, which membrane encloses a hollow space embodied in the sensor element on the side remote from the sensor support. The sensor element is secured in the recess by means of a glue between the sensor support and a bottom face of the sensor element oriented toward the sensor support. According to the invention, the glue constitutes a glue seam that extends around the hollow space of the sensor element between the sensor support and the bottom face of the sensor element and is only open on the side remote from the flow direction by means of at least one recess in order to ventilate the hollow space.

Abstract: A thermal-type flow sensor of high detection sensitivity and reliability in which a temperature measuring resistor is maintained at a predetermined temperature includes a plate-like substrate (1), a low heat capacity portion (13A) formed on a surface of the substrate (1), a heat generating resistor pattern (4) and a temperature measuring resistor (14) disposed on the low heat capacity portion (13A) and each formed of a heat-sensitive resistance film, and a control circuit (50) for applying a constant voltage (Vcc) to the temperature measuring resistor (14) while supplying a heating current (i) to the heat generating resistor pattern (4) for thereby outputting a flow-rate measurement signal derived on the basis of the heating current (i). The heat generating resistor pattern (4) and the temperature measuring resistor (14) are disposed essentially on a planar array along a direction in which a fluid destined for measurement flows.

Abstract: A sensor assembly has a substrate with a microchannel formed therein through which a fluid can flow. At least one sensor is proximate to the microchannel. The temperature of the at least one sensor or fluid may indicate the condition of the fluid, for example, the flow rate and the presence of gas bubbles and particulate substances.

Abstract: A thermo-sensitive flow rate sensor includes a flow rate detecting device that has a plurality of flow rate detecting diaphragms, each of which is provided with heating portions and temperature detecting portions. The plurality of flow rate detecting diaphragms are arranged in a direction perpendicular to a direction of flow of a fluid to be measured. Each of the flow rate detecting diaphragms is formed and placed so that the length of a longer side thereof is two times the length of a shorter side or more, and that the longer side thereof extends along the direction of flow of the fluid to be measured. Each of the flow rate detecting diaphragms has at least one of the heating potions and at least one of the temperature detecting portions, which are arranged in the direction of flow of the fluid to be measured.

Abstract: An integrated environment temperature sensor device provides improved temperature sensitivity by using a diode as the sensing element. The integrated sensor device comprises a heater element for creating a fixed quantity of heat energy. The sensor device also comprises an integrated circuit diode which receives the fixed quantity of heat energy from the heater element. The integrated circuit diode has a constant forward bias current applied thereto and a change in environment temperature is reflected in a voltage change across the integrated circuit diode. The integrated circuit diode further comprises an electrically insulating layer positioned substantially between the heater element and the integrated circuit diode for electrically insulating the two from each other.

Abstract: A mass flow sensor for measuring flow of a medium comprises a body, a membrane fixed on the body, a pair of thin film heating elements arranged on the membrane, and a sensing element arranged on the membrane adjacent the pair of heating elements and connected between the pair of heating elements. The heating elements are further arranged in a spaced relationship, transverse to the direction of medium flow such that one heating element is upstream of the other heating element in the medium flow. The sensing element provides an electrical signal for determining the voltage across the total series resistance of the heating elements which is indicative of the medium flow magnitude, and for determining the relative resistance of the upstream heating element compared to the downstream heating element which is indicative of medium flow direction. In another aspect of the invention a system for measuring flow of a medium is disclosed.

Abstract: Provided are mass and heat flow measurement sensors comprising a microresonator, such as a quartz crystal microbalance; a heat flow sensor; and a heat sink coupled thermally to the heat flow sensor. The sensors may be used to measure changes in mass due to a sample on a surface of the microresonator and also to measure heat flow from the sample on the surface of the microresonator by utilizing the heat flow sensor, which is coupled thermally to the microresonator. Also provided are methods for measuring the mass of a sample, such as a gas, and the flow of heat from the sample to the heat sink by utilizing such mass and heat flow measurement sensors.

Abstract: A highly accurate thermosensitive flow rate sensor is able to reduce the detection error of a flow rate even in the case of a flow accompanied by considerable intake air pulsation in an automotive engine or the like. A flow rate detecting section disposed in a main pipe is equipped with a support member having a first guide surface and a second guide surface for guiding a fluid on opposite sides thereof, and a flow rate detection element provided on the second guide surface of the support member. The second guide surface of the support member, on which the flow rate detection element is mounted, extends longer than the first guide surface in the downstream direction.

Abstract: A substrate is put in flow of fluid, on which substrate a depression is formed. A film is disposed on an opening plane of the depression. A pair of heating elements, through each of which an electric current flows, are formed on the film at an upstream side and a downstream side of the flow of the fluid. A constant temperature-distribution arrangement is made in which the temperature distribution in each heating element when the electric current flows therethrough is constant along a longitudinal direction perpendicular to a direction in which the fluid flows.

Abstract: A sensor has a membrane, on which at least one resistor element is situated. The membrane has a membrane layer which is composed of a plurality of partial layers. In addition, a covering layer is provided which is composed of a plurality of partial layers. The partial layers of the membrane and the covering layer are selected so that both in the membrane and in the covering layer light tensile stresses are set, the tensile stresses preferably being roughly the same.

Abstract: A method and apparatus for measuring the velocity of a fluid relatively independently of the physical properties of the fluid. This is preferably accomplished by spacing two sensor elements at different distances from a heater element. The present invention also contemplates minimizing the effects of the non-zero heater time lag and/or the non-zero sensor time lag for increased accuracy. This is preferably accomplished by either measuring the time lags and subtracting the values thereof from an uncorrected transit time measurement, forcing the sensor elements to track the thermal disturbance in the fluid thereby minimizing the effects of the sensor time lags, or measuring the transit time using sensors that have substantially zero thermal mass.

Abstract: A mass flow sensor having a thin substrate and a resistor element arranged on the thin substrate. The thin substrate is stretched on a fixed substrate. In a stretched area, at which, in response to mechanical loading of the thin substrate, the mechanical stresses concentrate, a resistor element for detecting ruptures is arranged. As a result of a rupture in the stretched area, this rupture-detection resistor is interrupted, and the rupture can be confirmed due to the sudden increase in the resistance of the resistor, caused thereby.

Abstract: Provided are mass and heat flow measurement sensors comprising a microresonator, such as a quartz crystal microbalance; a heat flow sensor; and a heat sink coupled thermally to the heat flow sensor. The sensors may be used to measure changes in mass due to a sample, such as a gas sorbing or reacting, on a surface of the microresonator and also to measure heat flow from the sample on the surface of the microresonator by utilizing the heat flow sensor, which is coupled thermally to the microresonator. The combined microresonator and heat flow sensor may provide simultaneous and continuous measurement of the changes in mass and heat flow at a gas-solid interface. Also provided are methods for measuring the mass of a sample, such as a gas, and the flow of heat from the sample to the heat sink by utilizing such mass and heat flow measurement sensors.

Abstract: Known sensor supports have a recess in which a sensor element is glued by means of an adhesive. The device according to the invention has a plate-shaped sensor element that is accommodated in a recess of a sensor support. A sensor region (3) has at least one measurement resistor, which region is exposed to the flowing medium wherein a gap remains between the sensor element and the recess. To protect an evaluation circuit connected to the sensor element against moisture, the provision is made, according to the invention, that at least partial regions of the evaluation circuit and partial regions of the sensor element are covered by a protective coating, wherein the gap has at least one enlargement by means of which the flow of the protective coating can be influenced. The device according to the invention is used for measuring the mass of a flowing medium in the intake air mass of internal combustion engines.

Abstract: The air mass meter a heating element and, downstream of the heating element, a disturbance body disposed in a duct element. The heating element and the disturbance body are geometrically shaped and arranged in the duct element such that the heating element is surrounded by a laminar flow at all the flow velocities of the air in the duct element which are operationally relevant to an internal combustion engine. The heat transmitted to the heating element is consequently determined only by the mass of the air flowing past and error-inducing flow disturbances are avoided.