Abstract: A time domain measurement and control system for a hot wire air flow sensor is disclosed in which the air flow sensor is of the type having a resistive heating element with an input end and an output end. The control system includes a fixed frequency variable width pulse generator which generates a pulse train through the heating element. This pulse train, furthermore, has a first predetermined voltage amplitude. The output voltage amplitude of the pulse train is determined at the outlet end of the heating element while a control circuit varies the duty cycle of the pulse train to maintain the output voltage amplitude at a second predetermined voltage level. The duty cycle of the pulse train is proportional to the air flow rate through the air flow sensor.

Abstract: A piezoresistive pressure sensor that makes use of n-type boron nitride as the piezoresistive material. The boron nitride enables the sensor to provide suitable performance in hostile environments. The sensor includes a titanium substrate covered with a diamond insulator layer. An n-type boron nitride piezoresistive element is deposited on the diamond layer, and is electrically connected to electrical contacts. The electrical contacts are electrically connected to a resistive measurement system for determining the resistance of the piezoresistive element. In an alternate embodiment, the boron nitride piezoresistive material is used in a micobolometer for a focal plane array.

Abstract: An EGR system comprises a vacuum-operated EGR valve and an auxiliary valve of a diaphragm type for assisting the operation of the EGR valve. A diagnostic control unit monitors an engine rotational fluctuation parameter such as a misfire parameter under the condition of EGR and judges that there is a possibility of abnormality in the auxiliary valve when the fluctuation parameter is greater than a first judgment value. In response to this judgment, the diagnostic control unit forcibly cuts off the EGR and calculates the fluctuation parameter under the condition of EGR cutoff. The diagnostic control unit concludes that the auxiliary valve is abnormal when the fluctuation parameter in the EGR cutoff state is smaller than or equal to a second judgment value which is smaller than the first judgment value.

Abstract: A stress testing apparatus includes a cylinder block 2 with twelve cylinders 4, each housing a piston 14. Hydraulic pressure is provided to each of the cylinders 4 by a common supply bore 6 for urging each piston 14 out of its respective cylinder 4. A stress testing device 16 is mounted over each cylinder 4 and piston 14. For tensile testing (see FIG. 3) of a specimen (X), a piston (14a) acts on the housing (28a) of the device (16a) through pins (26), to push the housing (28a) away from the cylinder block 2. The specimen X is mounted between the housing (28a) and the cylinder block 2. For compressive testing (see FIG. 4), of a specimen Y the housing (28b) is rigidly secured to the cylinder block 2, and the cylinder (14b) acts to compress the specimen Y between the housing (28b) and the cylinder block 2 through a shaft (22b).

Abstract: A magneto-inductive flow-measuring method for moving fluids, whereby the field coils generating the magnetic field are energized in gapped fashion and each measuring period includes a positive half-cycle of the magnetic field and a negative half-cycle of the magnetic field. The magneto-inductive flow-measuring method saves energy while at the same time permitting the simple and precise definition of the measuring signal by virtue of the fact that the measuring periods additionally include a section preceding the first half-cycle of the magnetic field and a section following the last half-cycle of the magnetic field, and that the additional signals measured therein are used to quantify an interference signal superposed over the measuring signal and to correct the measuring signal accordingly.

Abstract: An ultrasonic gas meter housing member is configured to provide an associated multi-configuration ultrasonic gas meter assembly. The housing member is installable in an ultrasonic gas flow meter which includes an internal flow measurement tube along which gas travels for flow measurement, the tube having an inlet end and an outlet end. The ultrasonic gas meter housing member includes a closed back portion and a front portion spaced from the back portion to define a space for receiving the internal flow measurement tube such that the tube extends across the internal space of the housing member. At least one wall portion extends between the back portion and the front portion, the wall portion having a first opening and a second opening therethrough for connection of the housing member to a gas inlet pipe and a gas outlet pipe. The gas meter housing member is symmetrical about a plane which divides the housing member into a first portion and a second portion.

Abstract: A port fitting (12, 42) is formed with a closed, pedestal end forming a diaphragm (12a, 42b) on which a strain gauge sensor (22) is mounted. A support member (16, 44) is received on the pedestal end and is formed with a flat end wall (16a, 44a) having an aperture (16c, 44c) aligned with the sensor. A portion of a flexible circuit assembly (24a, 58a) is bonded to the flat end wall. An electronics chamber is formed in a connector (18, 46) which is inverted and maintained at a selected height adjacent to the flat end wall of the support member to facilitate soldering of the flexible circuit to terminals (20, 48) in the connector and electronic components to the flexible circuit. The port fitting, when assembled to the support member, is also maintained at the selected height adjacent to the inverted connector to facilitate wire bonding the sensor to the bonded portion of the flexible circuit.

Abstract: A magnetoinductive flowmeter for moving fluids incorporates a measuring tube; an electromagnet including a field coil and serving to generate a magnetic field that extends at least essentially perpendicular to the axis of the measuring tube; a power supply serving to feed a switched-DC field current to the field coil; two measuring electrodes positioned along a connecting line that extends at least essentially perpendicular to the axis of the measuring tube and to the direction of the magnetic field; and a detection circuit serving to analyze the measuring voltage of the measuring electrodes and to generate a flow signal; as well as a current regulator controlling the field current and a control circuit controlling or regulating the voltage at the field coil of the electromagnet; as well as a changeover bridge connected to the input of the field coil of the electromagnet.

Abstract: A short-term fuel consumption (A) and a longer-term fuel consumption (B) or corrected longer-term fuel consumption (C) are calculated in a common quantitative unit, and comparatively indicated on a display (2), respectively by a bar graph (20) and a level pointer (211) having a graduated scale common thereto, visually aiding a decision by comparison therebetween.

Abstract: A torque transducer having a rotating shaft with first and second substantially rigid torque input members connected by a torsionally compliant coupling that enables angular deflection of the first torque input member relative to the second torque input member as a function of the magnitude of the torque in the shaft. First and second grating elements are attached to or integral with first and second torque input members, respectively. The grating elements have surfaces with alternating regions of high and low reflectivity connected by a torsionally compliant coupling. The surfaces are illuminated by a source of electromagnetic radiation (EMR), which generates patterns on one or more arrays of detectors sensitive to the EMR. The disposition of the patterns is a function of torque applied to the shaft, and the output of the one or more arrays can be processed to produce a measure of the torque applied to the shaft.

Abstract: In the embodiments of the simplified ink jet head described in the specification, a carbon body is formed with ink passages, such as internal passages extending through a carbon plate, pressure chambers on one side of a carbon plate, flowthrough passages on the other side of the same plate and ink supply passages, and a piezoelectric plate is affixed to the pressure chamber side of the carbon plate by a thin layer of epoxy adhesive. In one alternative embodiment, an ink jet head assembly contains two separate carbon pressure chamber plates, a carbon manifold plate and a carbon collar to retain the carbon plates in an assembly.

Abstract: An apparatus is provided for determining the mass flow rate of a fluid using thermal means. The apparatus utilizes resistance temperature detectors having substantially linear temperature dependencies to determine the mass flow rate of a fluid. The apparatus maintains a constant ratio between resistances of the first and second resistance temperature detectors, the amount of current necessary to maintain the constant ratio corresponding to the mass flow rate of the fluid. The apparatus includes a microprocessor wherein an algorithm relating the current and mass flow rate including thermophysical properties of the fluid, sensor thermal resistance, and probe stem loss information provides the fluid mass flow rate based upon calibration information. Operation in alternate fluids without the need for recalibration is possible utilizing calibration constants obtained in the primary fluid and substitution of thermophysical properties and stem loss characteristics of each fluid in which operation is desired.

Abstract: A torque sensing calibration unit comprises a hollow torsion bar (2) to which torque is to be applied, associated with two or more pairs or positions sensors (10, 11, 12, 13, 14, 15) each pair being arranged to measure movement of the bar on diametrically opposite sides of a central axis through the bar (2). The pairs of sensors are arranged to measure movement in mutually perpendicular directions.

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: A probe for use in monitoring intake air volume in an air handling system operates in a turbulent stream found at locations near an intake for outside air. The probe has a very large transverse peripheral profile and includes a front face having a very large impact area so as to substantially disturb the turbulent stream and effect a substantial change the direction of flow of the turbulent stream, enabling accurate measurement of differential pressures to determine intake air volume with greater precision.

Abstract: An ink-jet system has an ink channel between an ink reservoir and a nozzle, and an electromechanical transducer which comprises an expansible member arranged adjacent to the ink channel for abruptly reducing the volume of the ink channel in order to eject an ink droplet through the nozzle. The depth of a portion of the ink channel between the expansible member and the nozzle is larger than both the depth of the portion adjacent to the expansible member and the height of the nozzle.

Abstract: A flowmeter capable of measuring an accurate quantity of flow over a wide range of the quantity of flow. A measurement zone (15) for smaller quantity of flow and a measurement zone (16) for larger quantity of flow are determined inside a flow path (13) of a pipe (10). Regulating strainers (14) for regulating the flow of a gas (20) are disposed inside the measurement zone (15) for smaller quantity of flow by dividing the flow path (13) into a plurality of narrower flow paths (14A). A mean flow velocity of the gas (20) flowing through each of a plurality of narrower flow paths (14A) becomes substantially equal. A part of the gas (20) reaches nozzles (22a, 22b) erected across flow velocity sensors (15a, 15b) for smaller quantity of flow and is accelerated by the operation of these nozzles.

Abstract: The invention relates to a method for assigning identifiers, contained in signals emitted by transmitters in a tire pressure control system, to the position of the wheels where the transmitters are located. Said system comprises a pressure sensor, a transmitter and a transmit antenna on each of a plurality of wheels of a vehicle, one or more receive antennas on the vehicle body, and receiving and evaluating units connected to this body via cables. In this method, the signals containing the identifier are intercepted by the receive antenna(s) and transmitted to the receiving and evaluating units, where they are evaluated in accordance with their identifiers. The invention is characterized in that, for the monitored wheels, not just the air pressure in the tires, but also the acceleration obtained from the movement of the wheel is measured.

Abstract: A force transducer assembly for measuring compressive and tensile loads applied to a force transmission device, the assembly includes a housing, a sleeve assembly and a sensor device. The housing has a hollow interior. The sleeve assembly is coupled within the interior of the housing. The sensor device is secured within the interior of the housing between a portion of the sleeve assembly and a portion of the housing. The sensor device includes first and second sensors each including an isolation diaphragm at least partially defining an oil-filled cavity, and a piezoresistive sensor positioned so as to be effected by a change in pressure in the oil-filled cavity. When a first force is applied to the apparatus in a first direction via the force transmission device, one of the isolation diaphragms is deflectable in response thereto, and when a second force is applied in a second direction opposite to the first direction, the other of the isolation diaphragms is deflectable in response thereto.

Abstract: A sensor for measuring changes in mass air flow is described that uses one or more thermoelectric devices, each of which serves both as a heating element and as a differential temperature sensor. The thermoelectric device or devices are sandwiched between two surface plates. The sensor operates the device or devices in constant current or in pulsed current mode. The operation in constant current mode involves passing the current through one thermoelectric device to create a temperature differential between the two surfaces. A second thermoelectric device generates a voltage in response to the differential, the voltage being proportional to the air flow rate. In another embodiment, the device contains a single thermoelectric device that operates in a pulsed mode, first to create a temperature differential using an applied current, and then to measure the voltage. When the voltage reaches zero, the cycle is repeated. The cycle time determines the air flow rate.