pressure bell

例句：

1. 1. The pressure bell is used to indicate when the tank needs to be filled.
   压力报警器用于指示油箱需要加油。
2. 2. The engineers were monitoring the pressure bell readings closely.
   工程师们密切监控着压力报警器的读数。
3. 3. The pressure bell was triggered by a sudden drop in air pressure.
   压力报警器因突然的气压下降而触发。