Abstract: The invention is directed to an arrangement for checking the tightness of a vessel such as a tank system of a motor vehicle. The vessel can have a possible leak and this can be viewed as a first flow resistor. The arrangement includes a pressure source for generating a pressure change in the vessel and a pressure divider system is connected between the pressure source and the vessel which is subjected to the pressure change. The pressure divider system is defined by and includes the first flow resistor and a reference branch having a predetermined second flow resistor. A pressure sensor measures the pressure relationships in the pressure divider system. The invention provides a reliable statement as to a possible leak in the tank system of a motor vehicle while providing a simple and therefore cost effective manufacture. The pressure source used to check the tightness can be utilized for other tasks required in a motor vehicle. The invention also relates to a method for checking the tightness of the vessel.

Abstract: A flow sensor has a diaphragm and a resistive film positioned on the diaphragm. A heater is formed from the resistive film and temperature sensors are arranged on both sides of the heater. On both sides of the heater are additional temperature sensors, which are interconnected by an interconnect resistor and formed from the resistive film.

Abstract: The invention proposes a device for measuring the mass of a flowing medium, in particular the mass of air aspirated by internal combustion engines. The device has a platelike sensor element which is accommodated in a recess of a sensor carrier, and which with a sensor region that has at least one measuring resistor is exposed to the flowing medium in order to measure its mass. The sensor element is accommodated essentially flush in the recess and is retained in the recess by being glued to a bottom face in the recess. The bottom face of the recess of the sensor carrier has a troughlike indentation, which extends at least partially along the circumference of the sensor element outside the sensor region that has the at least one measuring resistor. The device according to the invention is intended to measure the mass of a flowing medium, in particular for measuring the mass of air aspirated by internal combustion engines.

Abstract: A device for measuring the mass of a flowing medium by use of a temperature-dependent measuring resistor bathed by the flowing medium and accommodated in a measuring channel. The device has a flow obstacle, embodied in the form of a trip edge, upstream of the measuring element in the region of an inlet opening of the measuring channel, so as to create a chronologically and spatially stable separation zone in the region of the trip edge, thereby preventing chronologically and spatially unstable separation zones and makes it possible to attain a reduction in measuring signal noise. The invention is contemplated for measuring the mass of a flowing medium, especially for measuring the aspirated air mass in internal combustion engines.

Abstract: In a method for correcting an output signal of an air mass meter, an air mass aspirated by an internal combustion engine is detected, so that first a characteristic of the air mass meter representing a relationship between an output voltage of the air mass meter and a flow air mass is determined, the characteristic in a region which the air mass can flow back is corrected by changing the characteristic in a return flow region relative to the measured characteristic, the change of the characteristic is performed so that the relationship between the output voltage of the air mass meter and the measured air mass is adjusted to minimize error measurements, and the computations of the aspirated air mass is therefore performed with the aid of the corrected characteristic.

Abstract: The device determines the pulsating air mass flow in an internal combustion engine. The device includes a sensor producing an output signal to be evaluated to determine a pulsating air mass flow and a filter device for filtering the output signal to produce a filtered signal in which the signal components characteristic of the air mass flow pulsations and dynamic changes are not attenuated but noise and other spurious signals are attenuated. The filter has a bandpass characteristic with an adjustable center frequency which can be varied as a function of rotation speed as well as a low-pass characteristic. A controller of the internal combustion engine is used to adjust the center frequency of the bandpass characteristic according to engine rotation speed.

Abstract: A devices for measuring the mass of a flowing medium, having a temperature-sensitive measuring element, in which accurate medium flow measurement can be made in the presence of a pulsating flow which is characterized by flow fluctuations. In order to provide accurate measurements, the device has a structure which is installed in the measuring conduit in a region of its inside wall upstream and downstream of the measuring element. The structure has friction faces exposed to the oncoming flow in which the friction faces effect a flow resistance which can be varied by the intensity of the flow fluctuations, only in the presence of a pulsating flow, so that the flow is positively displaced more or less into the region of the measuring element, in order to increase the flow velocity and to compensate for the measurement errors. The invention is for measuring the mass of a flowing medium in the intake of an internal combustion engine.

Abstract: A mass flow sensor includes a measuring element arranged on a membrane that is clamped in a frame. The sensor is formed by introducing a recess into a silicon wafer. Through the application of a recess having perpendicular walls, the thickness of the frame can be reduced, thus allowing the required surface area of the wafer to also be reduced.

Abstract: A mass-flow sensor includes a measuring element on a membrane and a media-temperature measuring element on a separate membrane. By configuring the media-temperature measuring element on a membrane, the mass-flow sensor quickly reacts to changes in the temperature of the flowing medium.

Abstract: An apparatus for determining the flow rate of a flowing medium in the presence of pulsating flows and/or backflows, having a substrate as a carrier and a resistor arrangement located on the substrate for sensing medium flows. The resistor arrangement includes a temperature-sensitive resistor (R.sub.s), a heating resistor (R.sub.h), and compensation (R.sub.k) and bridge resistors (R.sub.1, R.sub.2, R.sub.3), which are arranged to create a feedback circuit that establishes a constant temperature environment, allowing electrical measurement of the flow mass. The substrate includes a fixed portion at one end, and two unfixed legs at the other end, the two legs divided by a notch. The width of each of the first leg and the notch is from 30 to 50 percent of the total width of the substrate, while the width of the second leg is at least 10 percent of the total width of the substrate.