front end circuit meaning in English

前置电路

The measuring instrument for blade resonant frequency mainly consists of a front end circuit , a signal collecting circuit , and a coiilputing and displaying circuit . this paper provides a detailed hardware diagran , software flow chart and design process , expounds the operation and calibration of the instrument , and analyses the measuring data in detail according to different conditions
叶片共振频率测试仪主要由前置电路，信号采集电路及运算和显示电路组成，文中给出了详细的硬件电路图、软件流程图及设计过程，阐述了该仪器的使用和校验方法，并针对不同的状况对测量数据进行详细的分析。