flow quantity recorder

例句：

1. 1. The flow rate of the water is measured by a flow meter.
   水的流速通过流量计测量。
2. 2. The flow rate of the oil is controlled by a flow regulator.
   油的流速通过流量调节器控制。
3. 3. The flow rate of the gas is monitored by a flow meter.
   气体的流速通过流量计监测。