警けい報ほう器き

noun

alarm; alarm device; sensor

A device that detects danger, intrusion, fire, train crossings, etc. and gives a warning sound or signal. 警報器 emphasizes a device/detector, while 警報機 is also used for larger alarm mechanisms.

• 火か災さい警けい報ほう器きが突とつ然ぜん鳴なった。

  The fire alarm suddenly went off.

• 玄げん関かんに防ぼう犯はん用ようの警けい報ほう器きを取とり付つけた。

  We installed a security alarm at the entrance.

• 踏ふみ切きりの警けい報ほう機きが鳴なり始はじめた。

  The railroad crossing alarm began to sound.