| 摘要 |
<p>PURPOSE:To detect a conductor which is buried at a relatively deep position by providing the magnetic core of a probe with a detection coil and a magnetic by-pass, and supplying an exciting current to the detection coil and measuring apparent impedance variation. CONSTITUTION:One end of the magnetic core 4 of the probe 3 is brought into contact with the surface of a medium 1 where the conductor 2 is buried, and the magnetic by-pass 5 is connected to the other end of the magnetic core 4, which is wound with the detection coil 6. Then a power circuit 13 is connected to the coil 6 through a detector 10 to supply the exciting current and a measuring circuit 11 measures the apparent impedance variation of the coil 6. Here, the power circuit 13 is provided with a booster amplifier to apply a relatively large high frequency current to the coil 6 and the frequency and effective value of the exciting current is set to 2 - 100 kHz and 20 -1000 mA. Consequently, the arrival depth of the magnetic field in the medium is deep and the magnetic field gradient is large, so a reinforcing bar, etc., buried deeply in concrete can be detected with high accuracy and high resolution.</p> |
