In this paper, the characteristics of wedge ring detector (WRD) are introduced. The correcting method of the responding factor is discussed theoretically, and the experimented results are given.

This paper analyzes the reason producing surface leakage current of high resistivity detector, and adopts guard ring to reduce the leakage current.

When vehicles passing ring coil detector, the interaction of vehicle body's substance and ring coil changes resonant frequency of the ring coil and forms a curve of frequency variation.