PURPOSE: To discriminate exactly a position by driving a buried pipe by an acoustic wave sound source installed to a branch pipe exposed on the ground, and discriminating the buried position based on a detecting signal which has processed a detecting signal by an acoustic wave receiver on the ground by synchronizing it with a driving signal.
CONSTITUTION: When a buried pipe 1 is driven by an acoustic wave sound source of a continuous sine wave installed to a branch pipe (omitted in the figure) exposed on the ground, and an ultrasonic microphone of a buried position detecting device (omitted in the figure) on the ground surface is brought close the surface of a roadway 11 of a road 100, and moved in the direction S vertical to the vehicle running direction, a detecting signal A is obtained from an ultrasonic wave radiated coaxially from the pipe 1, and it reaches the highest detecting level H in its right above position, and decreases as the microphone is separated from the right above position. Also, the signal A is synchronized with a driving signal, therefore, the buried position of the pipe 1 is discriminated exactly without being affected by an external noise.
MACHI YOSHIO
GOSHIMA TOMOFUMI
ISHIZUKA HIROSHI
KOUNO MASARU
YAMAMOTO KUNIO
MACHI YOSHIO
GOSHIMA TOMOFUMI
FUJI DENKI SOGO KENKYUSHO KK
FUJI ELECTRIC CO LTD