The electromechanical gauge ACTS as an ammeter because the gauge reading changes with variations in the sender unit resistance.
机电仪表示一种电表，因为仪表读数在传感元件电阻中变化多样。
2
The PG's gauge display indicates the current operating pressure relative to the overall range of the unit.
就地压力计显示出当前相对于整个单位而言的工作压力。
3
Connect the vacuum pump to the compound pressure gauge; open the compound pressure gauge and vacuum pump to vacuum the indoor unit and connecting pipe.