True automated gate systems use vehicle and pedestrian sensors to ensure the safety and security of individuals nearby. Without a sensor, automatic gates can and will close on vehicles or pedestrians. In some cases, sensors are used to hold open gates until the vehicle pathway is clear. In other cases, sensors are used to open gates, with pedestrian sensors preventing moving gates from closing on pedestrians. There are several types of sensors used to control automatic gates. Below, TORXUN describes four of the most common ones and how they work.
Magnetic Loop Sensors
To make magnetic loop sensors work, a wire is placed within the vehicle drive lane. Magnetic loop sensors come in three variations: pre-formed direct burial, pre-formed saw cut, and hand-wired loops.
Pre-formed direct burial loops are embedded below the roadway surface and installed prior to the concrete or asphalt being placed. Pre-formed saw-cut loops are installed into a saw cut that is cut into existing concrete or asphalt surfaces. When installing a non-preformed loop, the installer places a jacketed wire into a saw cut. All loops placed in saw cuts require a filler to seal and protect the wire, which runs from the loop to the gate operator. The gate operator requires a loop detector for each function. Once the loop wire is connected to the loop detector and is powered up, the loop generates a magnetic field that will detect the presence of a vehicle.
Depending on the function of the loop, an exiting vehicle will pass over the “exit loop” to open the gate. A professional installer would also install safety loops; a proper installation would also have one safety loop on each side of the gate. The safety loops will hold the gate in the open position until the vehicle clears the gate opening. Typically, the space between the two safety loops is no greater than 16 feet. The idea being that you don’t want a vehicle to stop in any area within the gate without being on a loop. Larger gate opening requires a shadow loop.
A shadow loop is essentially a safety loop that is only active when the gates are in the fully open position. Remember that the loops react to metal, so metal gates cannot open over a loop. There need to be 3 to 4 feet between the gate and a loop.
Radar Movement Sensors
You can use radar movement sensors to detect moving objects within a particular area. These sensors are adept at detecting movement, but one downside is that they won't detect anything that’s stationary.
Motion Detectors
Another type of sensor that opens automatic gates is the motion detector. Motion detectors sense movement directly in front of the gate. These sensors work similarly to radar movement sensors but have a more limited range. Like radar movement sensors, motion detectors can only detect things that are moving.
Infrared Sensors
There are two types of infrared sensors: passive and active. Both sensors use thermal imaging to detect people and objects in the sensor's range. The difference between the two is that passive IR sensors only detect infrared radiation; active IR sensors emit and detect it. Passive sensors store an infrared image and open the gate when that thermal image changes. Active sensors activate when an object reflects the infrared radiation emitted by the sensor.
These gates require a fair amount of setup to ensure they operate correctly, but they work excellently once installed and configured.
At TORXUN, we create top-of-the-line automated gate systems. Our gate format is the fastest-growing in the industry; it's also one of the most versatile and user-friendly. Whether you need a parking solution, a pedestrian solution, or just want a reliable heavy-duty gate for your property, TORXUN can help. Contact us today to learn more.
