Development of a variable density flowmeter for an industrial application using tomographic imaging

A variable density flowmeter enables the mass flow of plastic nibs to be measured. The flowmeter is situated between the bunker discharge outlet valve and tanker. Measurement of the density distribution across the pipe using process tomography enables the mass flow into the tankers to be determined. A high frequency (1 MHz), eight electrode serial capacitance sensing system was developed. This was used primarily for imaging static objects and real time imaging up to 2-3 frames per second. To increase the imaging speed a parallel system (PT II) was developed. The PT II system consists of an eight electrode parallel capacitance sensing system, using a low frequency AC amplifier detector circuit. The use of a low frequency source has made the capacitance detector circuit stray immune and less sensitive to high frequency noise. A PC based, Texas TMS C40 parallel processing system is used to process data and provide the tomographic images.