SU508735A1 - Electromagnetic transducer for non-destructive testing of ferromagnetic materials - Google Patents

Description

ki are included differentially. The kokhmpensator 5 is made nz nefer-ro m of augmental material, for example copper. The number of turns of the komiensioi coil 3 is greater than the number of turns of the measuring coil 2 B p ipas, where 1,, 7. The body is made of dielectric.

Measurements with a transducer are performed as follows.

The transducer is mounted on a controlled ferromagnetic product, the junction of the excitation coil field and the constant bias field affect the junction. In the measuring coil, a signal of complex shape is induced, containing both even and odd harmonic components. In the compaction roller 3, an EMF is induced, caused only by the vortex tokum and does not contain even moiHHiK, since the compensator 5 is made of a non-ferromagnetic material. The displacement of the compensator is induced in the compensation coil emf. equals max emf. the measuring coil, and the difference signal contains only a header, carrying information about the material being monitored.

The accuracy of the control is enhanced by reducing the level of interference by bringing the material in the control zone to saturation (by a magnetizing field), for which the outer diameter of the magnet is chosen from the condition

0.1 1.0.

Yao

The proposed converter allows control of various ferromagnetic

Materials without change are compensated with Bbicd accuracy by the method of higher harmonics;

Claims (2)

1. Electro-magnetic converter. Non-destructive testing of ferro-machined materials, containing an excitation coil, positioned on its ends, and “selectively and partially” coils, included differentially, campenator and mapnit, covering the coils, characterized by the fact that, in order to improve the accuracy control and expansion of the range of controlled materials, the compensator is made of a non-ferromagnetic material, such as copper, and the number of turns of the compensation swing is greater than the number of turns of the test coil by a factor of l. where 1,, 7. 2. A transducer according to claim 1, characterized in that the outer diameter of the meter is selected from the condition I0, 1 , 0, // 0 where HO is the intensity of the constant sex magnetization;  the intensity of the indispensable sex field. Sources of information taken into account during the examination: 1. Thesis for the degree of Ph.D. Ostanina Yu. Ya. Control of multilayer products by the method of eddy currents. MEI, M., 1970 pp. 126-127, fig. 61; 2 Patent of Czechoslovakia No. 134649, M. Cl. 21 e 37/05.