| 摘要 |
PCT No. PCT/SE96/00785 Sec. 371 Date May 27, 1998 Sec. 102(e) Date May 27, 1998 PCT Filed Jun. 17, 1996 PCT Pub. No. WO97/03337 PCT Pub. Date Jan. 30, 1997A method and a device for inductive measurement of physical parameters of an object of metallic material by generating a time-varying magnetic field from a primary coil in a measurement range. The magnetic field induces eddy currents in the object which influence the time-varying magnetic field. The field is detected by a measuring coil from which a signal is obtained which carries information about the desired parameters. A field-measuring coil is introduced outside the measurement range, but surrounded by an electric circuit generated at the measurement range. The field-measuring coil senses a current induced in the electric circuit by the time-varying magnetic field. The interfering magnetic field generated by the current, and which influences the time-varying magnetic field, adds an error to the measurement of the measuring coil. The output signal of the field-measuring coil is thereby used to compensate the output signal of the measuring coil so that the error caused by the current in the electric circuit is eliminated. |
