| 摘要 |
The invention pertains to a process for testing a medium (1) for the presence of regions (2) of increased electrical conductivity and/or relative magnetic permeability, wherein the medium (1) is subjected to a magnetic field pulse and the change in the magnetic field of the induced currents is detected as a received signal in a magnetic field sensitive signal detection unit and is sent to an evaluation unit. According to the invention, a coil with high damping resistance (RD) is excited to produce a decaying oscillation, the oscillating magnetic field of the coil then interacting with the test medium (1); the coil voltage is detected with a receiving device; the signal components produced in the receiving signal by the parameters ( kappa 0 and mu r0) of the medium (1) are derived from this decaying signal, and with these signal components the received signal is corrected. |
