在选择外部感应设备的时候,用户应当停下来想一想:我是否真正需要这种设备?把这部分资金用在其他的地方是不是更合适?下面就是一些关于外部传感器的常识。 1 如果将掘壕等附加工作算在一起的话,外部传感器的安装成本是非常高的; 2 高昂的安装成本限制了外部 When choosing external sensing devices, users should stop and think about the following: Do I really need this device? Is it more appropriate to use this part of the capital in other places? Here are some common sense about external sensors. 1 If the additional work such as trenches is counted together, the installation cost of the external sensor is very high; 2 the high installation cost limits the external