| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable the measurement of the underground depth of a buried pipe easily from the ground in a short time by computing a dielectric constant or the depth of a buried object form the reflection time between transmitting and receiving electromagnetic waves and the interval between antennas. SOLUTION: Electromagnetic waves are transmitted from a transmitting antenna 4 toward the underground 1 and are reflected by a polyvinyl chloride pipe 2, and the reflected waves are received by the first receiving antenna 51 and the second receiving antenna 52. The reflection time between transmission and reception is detected by a reflection time detecting device 7 and stored in a storage device 8. Here, detection is repeated every time the transmitting antenna 4 and the two receiving antennas 51 and 52 are moved in a direction across the pipe 2 by a constant interval with the positional relationship among the antennas 4, 51, and 52 maintained. Then from the reflection time t1 at the time when the reflection time of either one of the receiving antennas becomes a minimum, the reflection time t2 of the other receiving antenna, and the intervals 2S1 and 2S2 between the transmitting antenna and each receiving antenna, a dielectric constant or the depth of the buried object is computed by expressions 1 and 2.</p> |
