Used primarily for 'Automatic Exit', which is opening a gate automatically when a vehicle drives up to it from inside a property.  In ground vehicle detectors can be either a loop of wire cut into a groove in a driveway or a probe buried next to the driveway.  Either way they are basically a metal detector so pick up vehicles only not pedestrians so if some one jumps the fence they cannot use it to open the gate.

Ground Loop Vehicle Detector  

Procon Loop Detectorsingle channel loop detector from Procon. Works from either 12V or 24V so is suitable for use with all brands of gate motor. Not suitable for solar systems.each $225.00 READ MORESolar Friendly Loop DetectorSingle Channel loop detector from Procon. Works from either 12V or 24V so is suitable for use with all brands of gate motor. Has very low power draw so can be used with solar gate motorsfrom $240.00READ MORE

Vehicle induction loops are normally made by cutting a groove in a concrete or bitumen driveway 25mm deep x 3mm wide in a rectangle 1m x 1.5m set about 6m from the gate.  The wire loop is made from 1mm2 or 1.5mm2 conduit wire (solid single insulated core) that runs between a loop detector in the gate motor or control box to the rectangle cut in the driveway then goes around the rectangle three times forming a magnetic loop of wire and then goes back to the loop detector in a continuous run with no joins. this then forms a pair of wires running between the detector and the loop which need to be twisted to minimise there magnetic effect. The tighter the twist the better other wise the metal gate even if its aluminium may cause a false trigger. The wire loop and twisted pair are held in the groove in the driveway with silicone and run in conduit alongside the driveway back to the gate motors control box.

When a vehicle drives over the wire loop in the driveway the loop detector senses the change in the magnetic field like a metal detector does and opens the gate.  

Loops detectors are the devices used for controlling traffic signals and can also be used to replace photocells on boom gates or barrier arms where the gate isn't near the ground.  Ground loops cannot be use under gates that are near the ground as a replacement for photocells as the gate will trigger it off.  The sensitivity of a loop detector needs to be correct as well because if too sensitive they can false trigger and cause the gate to open by itself.

Vehicle Detector Probe 

Are a small device buried 200mm to 600mm in the ground along side the driveway detecting vehicles moving within a 4m radius. The advantage of a probe is you don't need to cut a groove in your driveway and they are more cost effective.

The disadvantage of a probe is you cannot set a specific detection area you're stuck with the 4m radius so if your driveway is close to others you may pick up vehicles from next door.  They also detect movement only so if a vehicle pauses too long the gate may close on them.  Loop detectors can be set to sense the presence of a vehicle rather than the movement so is more suitable for Gated Communities or Commercial Buildings where there is a lot of users.  

Procon Vehicle Detector ProbeBuries in the ground to detect any vehicles passing for controlling automatic gates. Suitable for use with all brands of Gate Motor. Not Suitable for Solar Systems.each $255.00READ MORE

How they are Connected

Loop detectors and probes connect to the 'Open' input of the control unit for an automatic gate as these devices are used to open a gate only, they should not be connected to any input that can close the gate. The gate should be set to close automatically and have Photocells for safety. Photocells can also be used to control the closing of the gate.

READ MORE about Safety Photocells