ASTM E2561-07a (R2018) PDF Download

ASTM E2561-07a (R2018) is a standard practice that provides guidelines for the installation of inductive loop detectors. These loop detectors consist of wire loops, lead-in wires, and lead-in cables, and are used to detect vehicles in roadways for traffic monitoring or to control traffic signals. The practice specifies the method for installing the wires in saw cuts made in the roadway surface, rather than using preformed loops encased in protective enclosures.

The standard includes recommendations for various aspects of the installation, such as the number of turns of loop wire, the number and direction of twists in the lead-in wire and cable, splice location (if needed), and grounding options. It also mentions that modern inductive loop detector electronic units are capable of detecting vehicles even if the wire loop is laid on reinforcing steel before concrete is placed.