tachometer indicator

例句：

1. 1. The car's tachometer indicates the engine speed.
   汽车的转速表显示发动机速度。
2. 2.The tachometer is used to monitor the fuel level in the tank.
   转速表用于监测油箱中的燃油水平。
3. 3. The engineer checked the tachometer indicator before starting the engine.
   工程师在启动发动机前检查了转速表指示器。