Abstract: An ultrasonic flow measuring device, which determines volume and/or mass flow of a medium in a pipeline, or in a measuring tube. The flow measuring device includes a plurality of ultrasonic sensors, which emit and/or receive ultrasonic measurement signals along defined sound paths. The control/evaluation electronics of the flow measuring device is divided into an on-site electronics, in which at least one switch is provided, via which the ultrasonic sensors, arranged in different sound paths, can be driven and/or queried, and at least one remote, control/evaluation unit, wherein the control/evaluation unit so switches the at least one switch, that the driven and/or queried, ultrasonic sensor, or the driven and/or queried pair of ultrasonic sensors, is activated and provides measured values.

Abstract: An ultrasonic flow measuring device, which determines volume and/or mass flow of a medium in a pipeline, or in a measuring tube. The flow measuring device includes a plurality of ultrasonic sensors, which emit and/or receive ultrasonic measurement signals along defined sound paths. The control/evaluation electronics of the flow measuring device is divided into an on-site electronics, in which at least one switch is provided, via which the ultrasonic sensors, arranged in different sound paths, can be driven and/or queried, and at least one remote, control/evaluation unit, wherein the control/evaluation unit so switches the at least one switch, that the driven and/or queried, ultrasonic sensor, or the driven and/or queried pair of ultrasonic sensors, is activated and provides measured values.

Abstract: A clamp-on ultrasonic measurement system for a gas or fluid of low acoustic impedance, such as steam, two phase fluid or flare gas includes an ultrasonic signal transmitter which clamps to the steam or gas conduit, and first and second receiving transducers clamped in the shadow zone of the transmitter. The transmitter signal skips within the conduit wall with a characteristic skip distance Lp so ultrasonic signal energy is launched across the flow along plural paths over a region, and at an angle to the direction of flow. The receivers are positioned to receive the signal energy along different ones of said paths, modulated by tags or inhomogeneities in the flowing fluid. Cross correlation of the received signals then yields a peak correlation time interval or time delay from which the flow velocity is accurately determined.

Abstract: A sensor system includes an ultrasonic transducer head with plural transducing elements. The elements are arranged in pairs with the first one of each pair lying in a first plane and the second one of each pair in a second plane spaced a half wavelength away. For transmission, the two are driven out of phase, while for reception their outputs are combined differentially. By changing the drive frequency the transmitted beam is steered to compensate for changes in transducer alignment, or changes in acoustic path caused by abnormal temperature, pressure or flow velocity. In another embodiment, an assembly has a plurality of transducers aligned along slightly divergent paths. Preferred systems employ an upstream and a downstream transducer assembly, each of which is used to alternately transmit and receive signal energy.

Abstract: A flow meter, or flow path intervalometer, transmits a transmission signal modulated with digital pseudo-noise or similar code. The received signal is correlated with the transmitted signal at successive times to produce a correlation function having a peak at a time to equal to the propagation time. The code is selected such that the side lobes of the correlation function are small. An interpolator determines a precise time of maximum correlation. In one embodiment, upstream and downstream correlation functions are defined and are correlated to determine an upstream-downstream propagation time difference interval .DELTA.t. In a preferred embodiment the digital code is a Barker code, and the transmitted signal is a finite interval wave which is phase modulated by the Barker code. In another embodiment, the received signal is a reflected signal which is range gated so as to represent flow data originating from a desired region within the conduit.