压力真空表和真空表。
Combined Pressure and Vacuum Gauge and Vacuum Gauge .
油泵上压力表和真空表的作用不应忽视
Function of two gauges should not be neglected
泵不吸水,压力表及真空表的指针剧烈跳动。
Pump not suck water , indicator of pressure and vacuum meters severely jumps .