A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters (10, 110) and receivers (20, 120), one of which is set at an angle to the direction of flow that is different from the others.

Ultrasonic flow metering system

A fluid flow meter estimates the velocity of water or another fluid flowing through pipe by comparing measurements of the water velocity to one or more pre-determined templates. The fluid flow meter may collect measurement signals from one or more flow sensors, estimate the fluid velocity or flow rate by comparing the measurement signals to the template, and either store the comparison results in local memory, transmit the results to a remote memory or server, or both. In some embodiments, the fluid flow meter transmits the results to a server via a wireless interface. The transducers and processing system can be powered by a battery, a power line, or, for manifolds installed outdoors, a solar cell. Example transducers and processing systems may also have a passive wake-up feature for power reduction; that is, they may only draw power when water or another fluid flows through the pipe.

Methods and apparatus for fluid flow measurement

A method for estimating and correcting or at least reducing phase errors in received ultrasonic signals in an ultrasonic flow meter is disclosed, said method comprising the steps of: measuring one or more signals in the ultrasonic flow meter, which one or more signals depend on characteristics of one or more ultrasonic transducers in the ultrasonic flow meter, using the one or more measured signals for calculating an estimated phase error value, and using the estimated phase error value for correcting transmission times measured by the ultrasonic flow meter.

Ultrasonic flow meter

In the radar rangefinder (10), there is a transmitter (12) that receives pulses from a clock (14) and that produces RF burst pulses at the transmit antenna (16) Another clock (18) drives a receiver sampler (20) to sample radar returns on its associated receive antenna (22) The clock with the receiver (18) is typically swept in time relative to the clock with the transmitter (14) There is a timing control unit (24) to perform phase-locking The peak detectors (38, 40) and the comparators (42, 44) together form threshold detectors (46, 48) The transmitter peak detector (38) receives a delayed gate-off pulse from the Gate-Off Delay Generator (58) whose input is connected to the output of the transmitter flip-flop (50)

Precision short-range pulse-echo systems with automatic pulse detectors

Fluid flow rate is determined by transmitting ultrasonic pulses in both directions along a path through the fluid aligned with the direction in which velocity component is to be measured. Transmission of, and measurement upon, pulses in the two directions are controlled by a master clock pulse generator. The frequency of a first variable frequency oscillator is adjusted to fit N pulses exactly into the timer period for flight of an ultrasonic pulse along the path in one direction. The frequency of a second variable frequency oscillator is adjusted to fit N pulses exactly into the time period for flight of an ultrasonic pulse along the path in the opposite direction. The difference frequency is proportional to velocity component. This system may be combined with a limited sing-around system to improve resolution, at the expense of the time response.

Apparatus for indicating fluid flow velocity

An ultrasonic fluid flow metering system for use in monitoring volumetric flow of fluids conveyed in conduits or open channels. The flow meter includes at least one pair of transducers which alternately operate as transmitters and receivers to propagate energy through the flowing medium between the transducers. Pulses are applied to the transducers and the transit time of the pulse energy through the fluid in the two directions is utilized to generate frequencies which give an indication of the fluid flow. The system includes means for generating pulses which are transmitted through the fluid in opposite directions and a voltage controlled oscillator, the output of which is divided and used to provide delayed output pulses. The delayed output pulses are compared in time phase to the received pulses transmitted through the fluid in the conduit or channel and the frequency of the oscillator is controlled to provide time coincidence between the compared pulses. A count of the VCO output pulses over a predetermined period is alternately performed for upstream and downstream transmissions and the difference in the count provides a measure of the fluid flow.

Brown Alvin Edmund

Papers

Dual path ultrasonic fluid flow metering system and method

Verfahren und einrichtung zur stroemungsmessung