What is the function of an access control door sensor?

The function of an access control door sensor is primarily to detect occupancy near the door. This means it can sense when someone is approaching or standing near the entrance, which is essential for determining whether to grant access or trigger other electronic mechanisms like unlocking the door or activating alerts. By being aware of movement near the door, the sensor helps ensure that the access control system operates efficiently and enhances security by preventing unauthorized access.

The other choices, while they might involve different types of devices or functions, do not align with the role of a door sensor in the context of access control. For instance, unlocking doors automatically typically requires a different mechanism, such as an electronic lock or a keypad system. Monitoring door temperature might be relevant in specific contexts like HVAC control or fire safety but is not a standard function of access control door sensors. Recording entry times is typically managed by the access control system itself, which logs when users enter or exit but doesn't fall under the sensor's primary functions.