Showing papers on "Ultrasonic flow meter published in 1971"

Measurement of fluid flow rates

Abstract: Apparatus and a method for measuring the flow rate of a fluid in which a beam of ultrasonic ≮, electromagnetic, optical or other radiant.]. energy is transmitted across the flow at each of two positions spaced apart in the direction of flow, the noise amplitude, frequency or phase modulation on each beam due to disturbances in the flow is detected, and the two resultant signals are cross correlated to determine the time delay therebetween producing maximum correlation, i.e. the mean fluid transport time between the beams, and thus the mean fluid flow rate.

Linear readout flowmeter

Abstract: A flow meter for determing the rate of flow of fluid through a conduit and indicating the flow rate on a linear scale. A signal having a magnitude inversely proportional to the time elapsed for a substance carried by the fluid to travel a fixed distance is produced and converted into a flow rate indication.

Noninvasive measurement of peripheral arterial flow. Impedance cardiograph and ultrasonic Doppler flowmeter.

Abstract: A Doppler ultrasonic flowmeter and an impedance cardiograph were used for measurements in 30 patients with various arterial disorders. In five cases, the devices proved to have a determinant influence on clinical management by supplying data not otherwise obtainable at the bedside. Of the two instruments, the Doppler flowmeter proved to be more sensitive and more easily used, although only the impedance cardiograph has the potential for supplying information on total flow. The latter device lacks sensitivity in low flow states (less than 10 ml/min), but this can perhaps be overcome by using a venous occlusion method.

Spin testing apparatus for turbine-type flow meters

Abstract: An apparatus for measuring a performance-indicating parameter in a fluid flow turbine meter spin test in which the turbine meter rotor and other operative rotatable parts of the turbine meter are selectively accelerated and then allowed to coast so that the rate of the rotor rotational speed is dependent upon accuracyimpairing mechanical friction which resists rotation of the turbine meter rotor. The measured performance-indicating parameter is comparable with a reference parameter to determine if an increase has occurred in the mechanical friction which is developed by the operative meter parts under test. The measured performance indicating parameter may be the time required by the coasting turbine meter rotor to decay from one pre-selected speed to a lower pre-selected speed, or it may be the change in decaying rotor speed that occurs in a pre-selected time period.

Total Volume and Component Flow Measurement in Industrial Slurries and Suspensions Using Correlation Techniques

Abstract: Flow velocity can be derived directly from the transit time of natural turbulence signals between two transducers spaced along the direction of flow. The transit time is determined by cross-correlating the transducer outputs with either a special purpose correlator or an on-line computer. Advantages are that the time delay can be measured absolutely by the correlator, the flowmeters are relatively insensitive to the effects of up-stream disturbances, the transducers do not obstruct the flow, and suspensions and slurries can be metered. Results are presented for flow measurement of sand/water slurries using electrical conductivity and ultrasonic transducers, and for heavily loaded gaseous suspensions using capacitance transducers.A low cost mass flowmeter has been devised in which the mass flow of solids in a pneumatic conveyor is derived from measurement of variations in concentration intensity due to turbulence. Results are given for mass flow measurement of foodstuffs (flour, wheat and beans), pulverise...

Water turbulence detector

Abstract: A Doppler shift flow meter array detects turbulence in the wake of a submne. Three sets of transmitting and receiving sonic transducers are spaced in a line on a rigid support. The transmitting transducers emit ultrasonic energy which is reflected from particulate matter in a surrounding water medium. The reflected energy is detected by the receiving transducers. A digital Doppler meter associated with each set of transmitting and receiving transducers develops a digital count over a fixed interval that is equal to the Doppler shift between transmitted and received energy. First differences between adjacent pairs of digital Doppler meters are obtained by two digital subtractors, and the second difference between Doppler shifts is obtained by a third digital subtractor. The second difference is non-zero only when ocean turbulence is present, such as produced by a submarine.

Optical Current Meter Use in Southern California

Abstract: The optical current meter is a stroboscopic device with which an operator may visually follow and gage the velocity of particles moving on the water surface. From early prototypes the meter has evolved to a field usable instrument with a low power telescope, an oscillating mirror in the line of sight of the telescope, a variable-speed battery-powered motor, and a tachometer which indicates the rotational speed of the mirror. Surface velocities are computed knowing the distance to the water surface and the angular speed of the oscillating mirror. Surface velocities must be corrected by an appropriate coefficient to represent the mean velocity in the vertical. The optical current meter will find its principal use in measurements of discharge under conditions that preclude use of conventional stream-gaging equipment.

Measurement of Particle Velocity at a Shock Front in Water with a Laser Doppler Meter

Abstract: A laser Doppler meter was used to detect particle motion in tap water due to the passage of an explosively generated shock front. It was not necessary to introduce foreign particles or dust in the region of observation to serve as scattering centers. Optics of the system were aligned such that particle motion was monitored in only a small volume rather than over the entire ray path length. Particle velocities measured with the Doppler system were in agreement with those calculated from the response of a standard tourmaline piezoelectric pressure gauge placed adjacent to the region on which the Doppler meter was focused.

Phasic Renal Artery Blood Flow Velocity in Man During Cardiac Arrhythmias.

Abstract: Excerpt Phasic renal artery blood flow velocity was measured in 23 patients, utilizing the Doppler ultrasonic flowmeter telemetry system. The catheter tip containing the transmitting and receiving ...