摘要:
A method for cleaning of a measuring element (1) passed over by a gas flow is arranged on a thin-walled membranous material (5). The measuring element (1) includes at least one heatable element (6, 7, 8; 10, 11), which is arranged on the membranous material, the membranous material being capable of vibrating. By means of a control apparatus (20) or a switching (22) associated with the measuring element, a periodic delivery of current (41, 42) in intervals takes place in this manner to at least one heatable element (6, 7, 8; 10, 11) of the measuring element (1) and thereby produces vibrations. Alternatively, vibrations of the membranous material (5) can be produced by special vibration exciters or by means of ultrasonic coupling.
摘要:
A sensor chip having at least upstream from the sensor region, at least one potential surface that, by electrical interaction with the contaminants in the flowing medium, prevents precipitation in the sensor region.
摘要:
A gas flow determination method and a corresponding gas flow determination device. A sensor device including a diaphragm and a frame enclosing it is provided; a predetermined temperature profile is created on the diaphragm; the gas flow to be determined is directed over the diaphragm in a predetermined direction of flow; the change in the temperature profile caused by the gas flow is detected; and the gas flow is determined on the basis of the change thus detected. The temperature at a third location on the diaphragm upstream from the first location and optionally at a fourth location downstream from the second location is regulated at a value corresponding to the local value of the predetermined temperature profile. In this manner, the effect of soiling on the diaphragm may be minimized effectively.
摘要:
A device for measuring at least one parameter of a medium flowing in a line, particularly the intake-air volume of an internal combustion engine. Liquid particles contained in the line act upon a measuring element and influence a characteristic curve of the measuring element which is used to determine parameters of the flowing medium. The characteristic curve of the measuring element can be changed disadvantageously by solid-matter particles. In order to reduce the action of solid-matter particles on the measuring element, a protective grating is proposed in which side walls of channels of the protective grating form various angles of intersection with the flow direction. Solid-matter particles are thereby diverted into a path of motion around the measuring element.
摘要:
A measuring device serves to measure the mass of a medium flowing in a line along the primary flow direction, in particular the mass of aspirated air of an internal combustion engine. The measuring device has a measuring element bathed by the flowing medium, which element is disposed in a measurement conduit provided in the line. The conduit extends in an axial direction from an inlet opening of the measurement conduit to a deflection conduit. The deflection conduit leads to an outlet opening that discharges into the line at an outer face of the measuring device. In the surroundings of the outlet opening, at least one protuberance is provided on the outer face of the measuring device that has the outlet opening.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A plug-in sensor is provided which is suitable for determining at least one parameter of a fluid medium flowing in a main flow direction, especially of an intake air mass of an internal combustion engine flowing through a flow pipe. The plug-in sensor has a plug part that is able to be mounted in the flowing fluid medium, in a specified alignment to the main flow direction. In the plug part, at least one flow channel is provided having at least one inlet opening and at least one outlet opening, in the at least one flow channel at least one sensor is accommodated for determining the at least one parameter. The plug part has a profile at which at least one local pressure minimum sets in the flowing fluid medium. The at least one outlet opening is situated at the side of the plug part, in the region of the at least one pressure minimum.
摘要:
An ultrasonic flow sensor for measuring the volumetric flow rate of a flowing medium through a flow channel having a transducer array which is situated within the flow cross section of the flow channel and which generates ultrasonic waves which propagate in the flow cross section of the flow channel transversally to a flow direction of the flowing medium, the ultrasonic transducer array having an interlaid arrangement of transducer elements which act alternately as transmitting and receiving antennas, so that all emitted individual sound waves interfere to form common wave fronts.