Exit Control & Safety Devices
Exit control and safety devices are a necessary part of any automated or electric gate system. The most common types of exit control devices and vehicle safety devices are vehicle loops. For pedestrian safety, the most common device is the photo-cell or photo-eye.
Vehicle loops are formed from twisted wire that is either installed under the road surface (pre-formed loops) or cut into the existing asphalt or concrete roadway (cut-in loops). These wires form a magnetic field that will sense an automobile and that will initiate a programmed response to the gate system. Typically that response is to open, close or reverse, depending on what type of vehicle loop.
The Photo-Eye is used for pedestrian safety and is a device that emits a beam of light that is either caught by another sensor or reflected back to the original sensor using a reflective plate that is mounted to one of the gate post. This serves as an important safety device for pedestrians because if the beam of light is broken or interfered with then the gate will not close. It is similar to a vehicle safety loop in that it will prevent the gate from closing but a vehicle loop will not sense an individual because it detects large quantities of metal whereas a photo eye will detect anything that interferes with the beam of light, including a small child.