摘要:
An ultrasonic flow sensor for detecting a flow of a fluid medium in a flow tube includes at least one first ultrasonic transducer, at least one second ultrasonic transducer, and at least one waveguide configured to conduct ultrasonic waves between the at least one first ultrasonic transducer and the at least one second ultrasonic transducer by reflection on walls of the waveguide, and to enable the fluid medium to flow through. The ultrasonic waves are able to propagate between the first ultrasonic transducer and the second ultrasonic transducer on at least two ultrasonic paths. Sound energies of the ultrasonic waves transmitted on the at least two different ultrasonic paths differ from one another by no more than a factor of 100.
摘要:
A microcontroller having a computing unit and a logic circuit. The microcontroller carries out computations for a regulation or control in a vehicle. The computing unit is connected to the logic circuit, and the logic circuit has an arrangement for computing an exponential function and is configurable.
摘要:
A fuel vapor storage and recovery apparatus includes a fuel vapor storage canister, said fuel vapor storage canister comprising at least first and second vapor storage compartments filled with an absorbent material, for instance filled with activated carbon, at least a vapor inlet port, an atmospheric vent port and a purge port. Said fuel vapor storage canister defines an air flow path between said vapor inlet port and said atmospheric vent port during shut-off of the internal combustion engine of the vehicle. During purging cycles there is defined an air flow path between said atmospheric vent port and said purge port wherein said first and second vapor storage compartments are arranged in concentric relationship and wherein said first and second vapor storage compartments in flow direction are separated from each other by an air gap diffusion barrier.
摘要:
To improve environmental protection from hydrocarbon emissions particularly from vehicles a heater for fluids comprising heating elements of an electrically conductive monolith, wherein the heater comprises a passageway for the fluid to be heated with a defined flow direction of the fluid during heating operation, the heater comprising at least two heating elements arranged side by side inside the passageway, so that they are arranged in parallel with respect to the fluid flow, is proposed improved in that one of the at least two heating elements is a controlled heating element, which has a slightly larger heating power, and a temperature sensor is provided at or close to the downstream end of the controlled heating element, and wherein the temperature sensor is connected to a control means for temperature control during heating operation of the heater; and a method of operating such
摘要:
An ultrasonic measuring unit and a method for detecting ultrasonic signal run-times, in which the ultrasonic measuring unit has two ultrasonic transducers for coupling ultrasonic signals into a flowing medium. Analysis electronics are provided to be accommodated on or in a flow tube, in which a gaseous medium such as circulating air flows. A probe unit is accommodated in the flow tube, the probe unit being assigned a temperature probe having a flow around it, whose measured value is used for correcting a temperature signal detected by ultrasound.
摘要:
An ultrasonic flow sensor having at least one ultrasonic converter (A, B) for transmitting and receiving ultrasonic signals (A0, B0) and a receiver unit (4) that is connected to the ultrasonic converter (A, B) and determines a zero crossing (N) of the ultrasonic signal (A0, B0) as a reception time (t0) once the ultrasonic signal (A0, B0) has exceeded a predetermined threshold value (SW). The measurement precision can be significantly improved if the receiver unit (4) determines a piece of information about an amplitude (Amp) of the ultrasonic signal (A0, B0) and varies the threshold value (SW) based on the information determined.
摘要:
The invention relates to a method for determining the running time (t) of an ultrasound flow sensor (6) ultrasound signal (15) which is transmitted by an ultrasound transducer (A, B) to a measuring section (S), wherein the phase position (ΔF) of said ultrasound signal (15) is determined with respect to a reference clock (8) and a remaining part (r(t)) is determined as a measure of the running time (tmes) of the ultrasound signal (15). The measurement of the running time can be carried out in a particularly robust manner with a minimum use of hardware, when the phase position (ΔF) is determined with the aid of a quadrature-demodulation method consisting in inverting the received signal (15) in a segmented manner with the aid of a clock signal (8) and the phase of the off-set clock signal (9) and the remaining part (r(t)) is determined according to a characteristic quantity (ts) of the sound signal (15).
摘要:
An ultrasonic flow sensor having at least one ultrasonic converter (A, B) for transmitting and receiving ultrasonic signals (A0, B0) and a receiver unit (4) that is connected to the ultrasonic converter (A, B) and determines a zero crossing (N) of the ultrasonic signal (A0, B0) as a reception time (t0) once the ultrasonic signal (A0, B0) has exceeded a predetermined threshold value (SW). The measurement precision can be significantly improved if the receiver unit (4) determines a piece of information about an amplitude (Amp) of the ultrasonic signal (A0, B0) and varies the threshold value (SW) based on the information determined.
摘要:
An ultrasonic flow sensor is used in particular for measuring the volumetric or mass flow of a fluid in a pipe. The sensor includes at least one ultrasonic transducer which is capable of emitting and receiving ultrasonic signals. An ultrasonic flow sensor, having in particular a simple and cost-effective construction and which functions according to the principle of beam drift, includes an array of a plurality of ultrasonic transducers which is positioned on one side of the pipe, a reflective surface lying opposite the array on which the emitted ultrasonic signals are reflected, and a receiver electronic system which evaluates the ultrasonic signal received from the ultrasonic transducers.
摘要:
An ultrasonic measuring device having at least one ultrasonic transducer, an analyzer circuit, and a reflection surface provided within a flow pipe for a gaseous medium. The first ultrasonic transducer and the second ultrasonic transducer are inclined toward one another, the electronic analyzer circuit being situated between the first ultrasonic transducer and the second ultrasonic transducer. The reflection surface of a reflection device is designed to be essentially convex on its side facing the ultrasonic transducers.