Data acquisition system based on CompactPCI bus and FPGA for electrical resistance tomography

As a kind of visual measurement technique based upon variations in conductivity, electrical resistance tomography has great potential in process application. A new data acquisition system for electrical resistance tomography is described. This data acquisition system is built based on the CompactPCI bus and the FPGA. The application of the CompactPCI bus can make the single plane electrical resistance tomography system extended and upgraded easily to multi-plane by adding additional CompactPCI cards and simple changes of configuration in FPGA chips and software in host computer. Besides, the injecting method and strategy can be controlled flexibly by FPGA. Meanwhile, the desired signals are measured and processed using digital signal processing technique in FPGA chips. This approach allows the system flexible, fast and precise. The new data acquisition system is tested in laboratory, the speed of the system can reach more than 1500 frame/s at the 100 kHz sine wave injecting signal, even faster at higher frequency; the Signal-to-Noise ratio of the system can reach above 73 dB.