Some switches also contain a rheostat to control the brightness of the instrument panel lights. 一些开关也包含一个可变电阻器，控制仪表板灯的灯光亮度。
The control instrument receives the load current signal and speed signal and calculates an instantaneous flow value and a cumulative weight valve. 控制仪表接收载荷电流信号和速度信号运算一个瞬时流量值和累积重量。
