指示器，记录器监控发动机、熔炉、电网、水库或其它系统运作状况的仪器；指示板或仪表盘 An instrument used to monitor the operation or condition of an engine, a furnace, an electrical network, a reservoir, or another physical system; a meter or gauge.
那农民在他的田地四周筑起一道电网，以防闲人侵入。 The farmer built an electric fence around his field to put an end to trespassing.
