The Canoga™ 702 Microloop is a transducer that converts changes in the vertical component of the earth’s magnetic field to changes in inductance. Vehicles containing vertical components of ferromagnetic material “focus” the earth’s field, increasing the magnetic field at the sensor when vehicles move over the sensor. Changes in inductance can be sensed by a Canoga 9004 vehicle detector. The Canoga™ 702 Microloop sensor’s small size permits easy insertion into a 3-inch (7.6 cm) plastic conduit installed 18–24 inches (46–61 cm) below the road surface. Installing the sensors in a conduit leaves the road surface intact, bypasses the effects of poor pavement conditions and inclement weather, and virtually eliminates maintenance and service requirements.