operating zone meaning in English

操作区
工作区
作业区

Do not put hand ( s ) into operating zone or on any moving part of a machine
不要将手伸入机器危险区或搁在任何机器运动组件上。
In this paper ， it is presented that an algorithm based on the least square principle is described ， which calculate the magnitude of low - frequency fault components in order to distinguish the fault location ， and it solve the decreasing operating zone problem of zone i distance relays
本文提出一种基于最小二乘算法计算低频分量的方法来区分线路串补装置前后短路故障，从而解决距离段正向保护范围的缩短问题。