Which type of sensor would be used to detect unauthorized entry through a door?

The magnetic contact sensor is specifically designed to detect unauthorized entry through doors and windows. It operates using two magnetic components: one mounted on the door frame and the other on the door itself. When the door is closed, the two magnets are aligned, creating a closed circuit. If someone attempts to open the door, the magnets separate, breaking the circuit and triggering the alarm system. This mechanism is effective for door security, offering a reliable way to indicate when a door has been opened without authorization.

In contrast, while passive infrared sensors detect motion by sensing changes in infrared radiation, they are not specifically tailored for doors. Glass break detectors focus on the sound frequency of breaking glass, making them useful for windows but not directly applicable to doors. Acoustic sensors rely on sound patterns and could be less reliable in preventing unauthorized entry through doors, as they depend on distinguishing specific sounds rather than detecting physical intrusion.