A non-invasive and non-intrusive ultrasonic technique for measurement of the local phase fraction of fluid-fluid systems such as oilwater dispersions can have significant impact in the chemical and energy related industries and as such, improve the competitiveness of these United States industries in the world market. Such a diagnostic device is needed for energy efficient operation and control of process vessels used in the chemical, petrochemical, nuclear fuel reprocessing, and hydrometallurgical industries. Great potential also exists for applications to measure and monitor the water content in oil transported in pipelines. Phaedron Technologies, Inc., believes that such a device can be developed for these uses and made available at modest costs. The study described will provide the fundamental knowledge to determine the feasibility of this device. Since the technique is based upon the travel time of an ultrasonic wave through the dispersion, proper knowledge of the transmitted signal is essential for accurate measurements. Accordingly, the effects of droplet size, wall thickness and geometry, wall material, fluid-fluid composition and temperature, and pathlength of the transmitted wave on the structure of the response signal will be investigated for volume phase fraction of 0.005 to 0.05. The accuracy of the technique will be determined and the instrument will be tested on a two phase flow loop under turbulent flow conditions. These studies will lead to the demonstration of concept feasibility.The potential commercial application as described by the awardee: It is anticipated that this study will show the feasibility of a noninvasive and non-intrusive ultrasonic device to accurately measure and monitor the dispersed phase fraction of an oil-water dispersion. This device should have utility in industry for efficient operation and control of process vessels, for measuring and monitoring oil-water flows in pipelines, and for laboratory use.