Abstract：According to the ISO 7278-3:1998 standard, the double-timing pulse interpolation principle is discussed, the relevant formulas are derived.Based on the pulse interpolation principle,and the FPGA EP2C5T144C8 of Altera Cyclone II series as the core,an acounter with pulse interpolation function, which is used especially for flow calibration facilities is designed.Experiments have been conducted to the counter. The experimental results show that the resolution of the counter can reach 0.01% even if a few of the cumulative number of pulses are gathered.The timing accuracy of the counter is better than 0.1ms. The experiments on the bellprover gas flow standard facility show that in a relatively short calibration time and collected few accumulated pulse, the accuracy of the counter improves more than one order of magnitudethan the traditional method.
2014, Vol. 35 
