What is the primary function of a photoelectric sensor in gate safety?

• A. To detect an obstacle in the gate path by interrupting a light beam and stop or reverse operation
• B. To detect weather conditions
• C. To measure gate speed
• D. To detect moisture

Answer: (D)

A photoelectric sensor in gate safety is used to create a safety beam across the gate opening. The emitter sends a light beam to a receiver, and when that beam is interrupted by a person or object, the sensor signals the control system to stop or reverse the gate to prevent contact or injury. This obstacle-detection function is central to safe gate operation. It isn’t intended for weather sensing, measuring gate speed, or detecting moisture, which would require different types of sensors.