| 摘要 |
In the testing of electrically conductive test objects for the presence of flaws and the like using a transducer to generate electrical currents in the test object and to inductively sense such currents, drive signals of at least two different frequencies are use for the transducer and the different frequency component induced signals picked up by the transducer are processed in such ways that a testing process is obtained that has low LO (lift-off) dependence. The characterizing feature of the invention is that the signal processing is undertaken as a function of at least one variable which may be the lift-off distance. |
