Abstract: An ultrasonic flowmeter is disclosed that detects the speed, amount, and composition of a two-phase flow travelling through it. One or more ultrasonic paths corresponding to ultrasonic transducers are positioned to detect the velocity and speed of sound through one phase of the two-phase flow. A second ultrasonic path is positioned to travel through the one phase of the two-phase flow, but to reflect off the interface between of interface of the two phases. A third ultrasonic path is positioned to travel through the second phase of the two-phase flow, but once again reflects off the interface between the two phases. The information of transit times for ultrasonic signals along these ultrasonic paths provides the speed of the two-phase flows, the amount of the two-phase flows, and the compositions of the two-phase flows. A quality assurance check ensures that the measurements are accurate.

Abstract: An apparatus and related method for measuring the degree of stratified flow in a two-phase flow is disclosed. Alternate embodiments include a single transducer level detector and a multiple transducer level detector. Further, these level detectors may be either integrated into or used in conjunction with an ultrasonic flow meter, or may be used in conjunction with some other meter that determines speed of sound for the flowing gas.

Abstract: An apparatus and related method for measuring the properties and individual flow rates of a two-phase flow comprising a gas and a liquid is disclosed. This apparatus and related method also can determine whether the liquid is travelling in primarily a mist or stratified flow. More precisely, one embodiment of the disclosed invention uses measured parameters such as gain, standard deviation in upstream and downstream travel times for an ultrasonic signal, measured speed of sound, noise, signal quality, batch failure rate, and velocity profile to infer the amount of liquid in the gas flow, and in what form the liquid is travelling. For a horizontal two-phase flow, an internal measurement can be used as a dry gas reference, although the invention is also applicable to a vertical flow. For increased confidence, these determinations may be corroborated by the disclosed liquid level measurement device.

Abstract: Disclosed is a method for measuring the amount of liquid in a volume of gas and the associated flow rates. A method of determining the percentage of a liquid present in a volume of gas is provided. The method comprises the steps of impressing the volume of gas with ultrasonic energy, receiving the ultrasonic energy impressed upon and traversing the volume of gas, measuring the received ultrasonic energy which has traversed the volume of gas, evaluating various parameters of the measured ultrasonic energy for variations which variations are a function of the liquid fraction in the volume of gas. A method is provided for determining the flow rates associated with a liquid-gas mixture.

Abstract: An apparatus for measuring the time of flight of a signal is provided. The apparatus for measuring the time of flight of a signal comprises a transmitter for emitting a signal, a receiver for receiving the signal from the transmitter, and means for detecting the onset of the signal as it arrives at the receiver such that the period of time from emission by the transmitter to the time the receiver initially receives the signal can be determined.