| 摘要 |
The invention relates to methods of eddy-current control of articles made of non-magnetic materials and can be used for contact-less determination of specific electric conductivity of constructional materials at non-destructive control of constructions and articles in metallurgy, machine-building, transport, aviation, etc. The eddy-current method for measurement of specific electric conductivity of non-magnetic materials is in that in material of the object of control eddy currents with given working frequency are excited. After that the output signal of the eddy-current transducer is balanced through adding compensation signal to it, with placement of the eddy-current transducer in the control zone, with measurement of amplitude and phase of total signal, values of those are used for determination of specific electric conductivity of material of the object of control. At that through displacement of the eddy-current transducer the gap between its working surface and the surface of the object of control are changed. In the process of displacement of the eddy-current transducer amplitude and phase of total signal are continuously measured. The value of phase of total signal at instant when the amplitude of total signal is a pre-set reference value is fixed, by that specific electric conductivity of the material of the object of control is determined. The technical result of the invention is in increase of the range of offset from the change of the gap between the eddy-current transducer and the surface of the object of control, selective measurement of specific electric conductivity irrespectively of selection of working frequency, increase of accuracy. |
