Loop detectors are among the most common sensors available in the market currently. They are widely used for detecting cars around gates, control barriers, intercom systems, ticketing machines, and boat docks. Loop detectors offer the most reliable ways to see vehicles in the current market. They work by detecting metal, so they are also found in places such as car parking lots, toll booths, and most commonly on the streets around traffic light signal points. 

Modern loop detectors work quite well and are also easy to install and troubleshoot, making them the most common choice for vehicular detection. 

What Is Loop Detection And How do they work?

Loop detection works by using an induction loop (usually made of copper wire) located on the road surface. This wire is connected to a loop detectors, creating a magnetic field in the electrical coil (a metal stick). This may sound like it doesn’t make much sense, but it’s pure physics, and the electromagnet used in these detectors are pretty easy to understand. When a vehicle passes over this detector, the magnetic field is disturbed by the vehicle’s metal, thereby triggering the sensor for identification. 

Using this detection system, loop detectors work in places like fences, industrial and mansion gates, parking booths etc. The most commonly used loop detectors are inductive loop detectors used under roadways around traffic signals. In traffic signals, when the vehicles stop over these detectors, the electromagnetic field change is noted, and this detection shows up on the traffic light control system. 

Generally speaking, a smaller size car causes a higher range of frequency disturbance in the loop detectors than a vast, heavy truck. This is because the metal undercarriage of the smaller cars comes closer to the loop detectors. Think of a compact sports car with an undercarriage that is exceptionally close to the track’s surface than a huge utility truck that is at least a foot above the ground, so the frequency trigger is more significant with a smaller car. 

Size And Proper Installation of Loop Detector

The size of loop detectors varies according to the size of the road or driveway and the estimated vehicular size that would pass over the loop detectors. 

Installing the loop detector properly is of utmost importance as this will ensure proper operation and trigger detection. Generally speaking, all loop detectors work on the same physics principles and offer more or less the same reliable results considering they are correctly installed. Some materials and features may vary from brand to brand, but installation is pretty similar. You should make sure to follow the proper guidelines mentioned by the specific brand. 

The few features you need to bear in mind for successful installation of loop detectors are as follows:

• The copper trigger wire needs to be placed at least 1 inch under the road, but make sure the wire is not buried more than 6 inches deep. This wire also needs to be placed securely with a backer rod with proper use of sealant. 
•  When installing, make sure to cut the loop detector wire at an angle of 45 degrees rather than 90 degrees. This will ensure a reduction in wire tension and erosion as these can result in false triggers, causing you to do repeated servicing for your loop detectors system. 
• To avoid further false detections when using multiple loop detectors within the same installation range, make sure to set all of them in different frequencies. For example, if one is set with a free exit loop, make sure the other is a reverse loop. Doing this will help you avoid cross signalling triggers which often result in false detections.