Traffic Loop Detectors Installation Guide

A loop that has been performed and connected to an extension cable Loop extension cable is used to connect the preformed or saw cut loop to the vehicle loop detectors, typically placed indoors or in a weatherproof enclosure. The extension cable’s characteristics are just as critical as the loop wire’s characteristics. Use only 14 gauge, 16 gauge, or 18 gauge stranded, twisted, shielded cable with a polyethylene insulation jacket. Solder the extension cable links to the loop wire and the vehicle detector wires. 

No other means of communication should be used. The distance between the loop and the detector can be securely extended to 300 feet with the correct extension cable; however, confirm this with the vehicle detector manufacturer.

Loop Vehicle Detector 

A proper installation and material are needed for vehicle loop detectors to function correctly! In general, loop vehicle detectors from all manufacturers operate on the same concept and will all function reliably if correctly installed and the proper materials are used. Vehicle detector features vary by manufacturer, but the majority are straightforward. The following characteristics need special consideration. 

Number of Outputs

The majority of traffic loop detectors include a switch closure through a relay, which is usually set to normally open. The number of outputs given and how they can be configured may be significant. More and more devices, especially in drive-thru environments, such as audio communication, car timing, message greeting, electronic menu boards, gates, and so on, must be activated by vehicle detection. Determine the number of devices used with the vehicle detector now and in the future, and make sure the number matches or exceeds the number of available relay outputs. 

Signal Type

Vehicle loop detectors in Wollongong produce a signal with a constant presence. In other words, the relay output is closed for the entire time a vehicle is present on the loop and does not reopen until the vehicle drives away. Most devices need this type of output signal; however, others require a pulse form, which will only close the relay for a brief moment when the vehicle is detected.

Examine the specifications of the devices you want to attach to the detector. If you attach more than one device to the detector, ensure that the sensor can simultaneously provide all of the appropriate signal types. Some detectors can only produce a kind of signal output at a time.

Diagnostics

Traffic loop detectors diagnostics through the detector’s communication port. Diagnostic software provides a visual representation of what is happening at the loop and can assist you in troubleshooting any issues that might arise during implementation or in the future. Detectors with this feature are usually in the same price range as other detectors and can save you time troubleshooting a detection problem.

The PC software and cable are generally extra; however, bear in mind that if you have several installations, you only need to purchase the software and cable setup once. The width and location of the loop in the pavement can also be determined using diagnostic tools.

Location of Loop 

The location of the loop about the vehicles you are attempting to detect is critical. Vehicles approaching a fast food restaurant drive-thru lane will come to a complete stop at the menu board, with the driver’s window aligned with the speaker post. The front axle is the only metal surface in the same relative position to the driver from vehicle to vehicle. Because of this, the traffic loop detectors are designed to detect the front axle rather than the engine. As a result, the loop should be placed 12 to 2 feet ahead of the speaker.