用计时-计频方式精确测量涡街流量计信号

涡街流量计是一种测量流量的传感器 ,其输出信号是与流量成正比的脉冲频率信号 ,在不同介质和管径中测量流量时所对应的输出信号频率范围不同 .采用常规定时采集信号脉冲数的方法容易在低频率产生误差 .为了能够精确获取涡街流量计在低、中频段的信号 ,采用了输出脉冲信号计时与计频方式相结合的测频方法 .重点介绍了交点频率的计算方法和误差分析 ,提供了用单片机实现这两种方法的测量原理和硬软件设计思路 .

A precise measurement for vortex flow meter signal based on time-frequency metering

The vortex flow meter is a sensor utilized to measure flow which output signal is a pulse frequency signal in direct proportion to flow which frequency ranges are different in different medium and pipes. The method of measuring frequency via routine timing is easy to produce error in the low frequency. In order to obtain the signal accurately in the low and medium frequency,the methods of measuring frequency based on both time metering and frequency metering for the pulse signal of vortex flow meter are adopted. The compute method and error analysis of intersection frequency as well as the measuring principle and designing concept of hardware and software of two methods via single-chip computer are focused.