To avoid overcrowding inside places with limited space, one of the measures adopted is to limit access, allowing entry only to a maximum number of customers. By connecting a photoelectric sensor to a counter, installed on one of the two sides of the entrance and exit doors, access can be blocked when the limit number is reached. The beam emitted by the photocell stops when people pass, thus increasing the number registered by the meter and decreasing it if the passage occurs through the exit door. A traffic light installed outside and connected to the meter will inform customers if it is possible or not to enter the room. The QM series retro-reflective cubic photoelectric sensor by Datasensing is the ideal solution for narrow passages, having a nominal detection distance of 7 m.
