This Small Business Innovation Research (SBIR) Phase II project will develop a highly innovative, high-speed optoelectronic sensor system capable of continuously monitoring molten metal alloy compositions during casting and melting operations. The goal is to design and construct a commercially-viable sensor system capable of performing highly-accurate quantitative measurement of molten aluminum alloy compositions in an aggressive industrial setting. Development of this sensor is among the highest priority technology needs identified by both the metal casting industry and the aluminum industry in their industry roadmaps of the future. In order to effectively compete, U.S. metal industries must increase their use of low cost scrap and must also find ways to increase production efficiency. The proposed sensor will acquire critical compositional data thousands of times faster than current commercial methods and will operate on a real-time basis without the need to place the sensor in contact with the molten metal. At these speeds, a melt shop could produce one extra metal production batch ('heat') per day, resulting in a 15% increase in productivity. The incorporation of this innovative optoelectronic sensor system will result in a tremendous increase in production efficiency, providing for a 15% gain in productivity. Thus, the $30 billion aluminum smelting industry could realize a $4.5 billion increase in production output with little or no additional capital investment other than the cost of the sensor system. In fact, the most immediate broader impact of the proposed activity will be to enhance U.S. competitiveness of aluminum casters and smelters because of this productivity improvement. In addition, the proposed technology will have a significant positive effect on process control and quality assurance, thereby providing further competitive advantages. Broader impact to our society will also be brought about through reduced emissions and energy savings resulting from shorter melting cycles. Similar improvements would be possible for zinc, copper, brass, bronze, iron, ceramic and glass industries that also have need for a similar continuous sensor system to monitor and control composition and quality on a real-time basis