Design of High Speed Cross Section Measurement System and its Real-Time Performance Analysis

This paper presents the development of a new cross section measurement system for on-line measurement of two-phase flows. To improve the real-time performance of the cross section measurement system, the parallel data acquisition system is designed, which has 16 channels of amplifiers, 16 channels of demodulators and filters, and AD card with 16 channels, can get the boundary voltage from 16 electrodes synchronously. Compared with the parallel data acquisition system, the former systems need to get the boundary voltage one by one, by this system the real-time performance is improved obviously, this system costs only 1/13 of the former system processing time. Several units of the system are analyzed, the principle of the multiplication demodulation was analyzed, especially, the low pass filter was analyzed, which costs most time of the data acquisition processing. The system performance is analyzed, a data acquisition speed at approximately 1000 dual-frames per second can be achieved.