Sensor for detecting vehicle presence in traffic lane, has conducting mass forming electromagnetic insulation between electromagnetic loop and part of space around loop, and detection circuit exciting loop to generate radiation field

摘要

The sensor has an electromagnetic loop (6), and a conducting mass (7) such as aluminum or its alloy, arranged for forming an electromagnetic insulation between the loop and a part of a space around the loop. The sensor presents a sensitive front side and an insensitive rear side, for making it directional. A detection circuit excites the loop at a determined frequency for generating a radiation field around the loop. An independent claim is also included for an installation including a sensor that is placed above a traffic lane.