In a mercantile burglar alarm system, which external device is attached outside the building?

• A. Siren inside the store.
• B. Motion detector.
• C. Camera outside.
• D. External tamper-protected alarm sounding device.

Answer: (D)

In this type of system, the goal is to have an audible alert that can warn off a thief and notify responders even if someone tries to disable interior components. The external device attached outside the building is the tamper-protected alarm sounding device. It is designed to be mounted outside so the alarm can be heard from outside the premises, helping deter theft and alert authorities. The tamper protection locks down against attempts to open or disable the unit, which is essential for maintaining the integrity of the alarm signal.

Siren inside the store stays within the interior space, so it doesn’t serve the external audible function. A motion detector is typically placed inside to sense movement in protected areas, not to produce an external alarm. A camera outside can be helpful for recording and may aid monitoring, but it isn’t the alarm sounding device. The external tamper-protected alarm sounding device is specifically the component intended to emit the audible alert from outside while remaining secure from tampering.