Which statement best describes multi-beam door protection devices?

The statement that the entrance is continuously scanned for obstructions accurately captures the primary function of multi-beam door protection devices. These devices are equipped with multiple infrared beams that form a protective "curtain" across the door opening. When something interrupts these beams—such as a person, object, or even an animal—the system senses the obstruction and sends a signal to the door operator, preventing the door from closing. This mechanism is essential for ensuring safety, as it helps to avoid potentially harmful situations where a closing door could strike an obstruction.

Continuous scanning is a vital feature because it allows for real-time monitoring of the door area, enhancing safety consistently rather than intermittently. This design is particularly useful in high-traffic applications where objects or individuals may frequently enter the doorway and require immediate recognition by the device to facilitate safe door operations.