Translation guide
A device that detects smoke and sounds a warning, typically installed in homes and buildings for fire safety.
The learner wants to refer to the physical smoke alarm unit, commonly found on ceilings.
Standard term for a smoke detector/alarm. Often used in technical or official contexts.
If the smoke alarm goes off, please go outside immediately.
Literally 'fire alarm device'. Commonly used for smoke alarms in residential settings. Often refers to the whole alarm system.
I need to replace the battery in the smoke alarm.
More specifically 'smoke detector', emphasizing the detection function. Slightly more technical.
This smoke detector is very sensitive.
Formal term for 'residential fire alarm'. Used in legal or safety regulations.
Installation of residential fire alarms is mandatory.
The learner wants to describe the sound or the event of the alarm going off.
General phrase for 'an alarm sounds'. Can be used for smoke alarms, fire alarms, etc.
The alarm went off because of the smoke.
More specific: 'the fire alarm activates'. Often used in formal or written descriptions.
The learner wants to talk about the importance or function of smoke alarms in general.
When discussing the concept, use the same terms as for the device. Japanese does not have a distinct abstract term.
Smoke alarms save lives.
In casual conversation, 火災報知器 is sometimes shortened to 報知器 (ほうちき), but this is less precise and may refer to any alarm. Stick to full terms for clarity.
火災警報 (かさいけいほう) means 'fire alarm' as a warning signal or announcement, not the device itself. Use 火災報知器 for the physical unit.
The fire alarm activated and everyone evacuated.