| 摘要 |
<p>PURPOSE:To prevent relative dielectric constant of ground by measuring the relative dielectric constant of natural ground directly through the detecting section of a device for measuring the specific permittivity of soil near a transmission/reception antenna thereby calculating the distance to the natural ground. CONSTITUTION:When a mode switch 10 is switched to the side for measuring relative dielectric constant, transmission/reception antennas 6, 7 of a specific permittivity meter 5 are connected respectively with a pulse generating circuit 11 and a sampling circuit 12 in order to measure the dielectric constant of nearby soil. When the mode switch 10 is switched to the side for detecting collapse, antennas 3a, 3b of a cutter collapse detector body 4 are connected respectively with the pulse generating circuit 11 and the sampling circuit 12, and a trigger signal fed from a trigger circuit 13 causes transmission of pulse signals having predetermined period to the transmission antenna 3a. Signals received by the reception antenna 3b of the sampling circuit 12 are fed to an operating circuit 14 where the reflection time of electromagnetic wave is operat ed and the distance to a natural ground is displayed on a display 15.</p> |
