DETECTION OF MOISTURE IN SOIL, DETECTOR AND MONITOR APPARATUS

摘要

PROBLEM TO BE SOLVED: To always monitor the penetration of water into soil of a bank or the like by oscillating elastic waves from an elastic wave oscillator arranged in soil to detect the elastic waves transmitted corresponding to the quantity of moisture in soil by an elastic wave detection sensor provided in soil. SOLUTION: An elastic wave oscillator 4 and elastic wave detection sensors 50-52 are embedded in soil of a bank 1. The oscillator 4 consists of a piezoelectric element 4a and a waveguide rod 4b and the piezoelectric element 4a becomes a vibration source by pulses from an elastic wave trigger circuit 6a and elastic waves generated by the piezoelectric element 4a are discharged to the peripheral soil through the waveguide rod 4b. When moisture penetrates into the bank 1 to enter the soil between the oscillator 4 and the sensors 50-52, an acoustic system is formed. The elastic waves oscillated from the oscillator 4 is transmitted through the formed acoustic system to be detected by the sensors 50-52. The detected elastic wave signal is amplified by an amplifier 6b and the output thereof is inputted to a processing part 7 along with the reference signal of the elastic wave generator 6a to calculate the quantity of moisture.