(1)设计4位十进制频率计测量范围: 1Hz～9999Hz (2）测量的数值通过4个数码管显示 (3）频率超过9999Hz时，溢出指示灯亮，可以作为扩大测量范围的接口-(1) the design of four decimal frequency measuring range: 1Hz ~ 9999Hz (2) measurement values through four digital tube display (3) the frequency of more than 999