A multi-interface level measurement system using a segmented capacitance sensor for oil separators

Abstract
A multi-interface level measurement system using a 64-segment capacitance sensor has been developed for use in oil separators. It can not only locate the multi-interfaces between different phases, such as gas/oil, oil/water and water/sludge, but also detect the foam layer between gas and oil. Experimental results show that the interfaces of gas/oil and oil/water can be easily identified by using a simple normalized difference algorithm and the foam signal has a unique spectrum that can be acquired by fast Fourier transform analysis.