Loop Detector FAQ
Q.What is an inductive loop vehicle detector and how does it work?
A. The complete detector consists of a loop of wire and an electronic detection unit. The operation is based on the principle of metal detection. As an example, a metal detector has a movable “coil” (or loop) which is waved above a buried metal object, which disrupts the electrical field generated by the loop and causes the metal detector to respond with an output, usually an audible tone. With a vehicle detector, the loop is buried in the roadway and the object to be detected is a vehicle. When the loop detects the vehicle, the detector provides a relay switch closure output.
Q. What is a loop coil?
A. The loop consists of one or more turns of wire located in or under the pavement and wound in a square, rectangle or circular form. There are two types of commonly used loops, the “saw cut” loop and the “preformed” loop.
Q. How is the detection/loop system applied?
A. When a set pattern of loops are buried on either side of a gate or door and connected to a vehicle detector, the system will detect the presence of a vehicle. This signal can be connected to operate the gate or door trigger. When properly programmed with the operator, the gate or door will open and remain open as long as the loop detects the presence of the vehicle. When the vehicle leaves the loop the gate or door is allowed to automatically close.