测量范围要求 1Hz-10MHz（输入信号幅度为0.5V-5V）。

基本性能要求 f为10MHz时，频率绝对误差不大于1000Hz； （高频精度）

f小于1000Hz时，频率绝对误差不大于1Hz。 （低频精度）

提高性能要求 高频精度提高： f为10MHz时，频率绝对误差不大于100Hz。

低频精度提高：f小于1000Hz时，频率绝对误差不大于0.5Hz。

-Requirements of measuring range 1Hz-10MHz (input signal range of 0.5V-5V). F the basic performance requirements for the 10MHz, the frequency of absolute error not more than 1000Hz　(high-frequency accuracy) f less than 1000Hz, the frequency of absolute error no greater than 1Hz. (Low-frequency accuracy) to improve the accuracy of performance requirements to improve high-frequency: f to 10MHz, the frequency of absolute error not more than 100Hz. Low-frequency accuracy: f is less than 1000Hz, the frequency of absolute error no greater than 0.5Hz.