| 摘要 |
FIELD: nondestructive testing; applicable in nondestructive testing of conducting objects. SUBSTANCE: electromagnetic converter for nondestructive test unit consists of outer dielectric framework 1 and inner dielectric framework 2 made for rotation round each other, the first group pickup loops formed by pickup loops 3 and 4, the second group of pickup loops formed by pickup loops 5 and 6 and group of excitation coils 7-10 enveloped by pickup loops 3 and 6. Pickup loops of each group are coaxial and located in one plane with radial clearance. Each group of pickup loops 3 and 4 and 5 and 6 are balanced in uniform magnetic field. In this case, the relation between turns of outer and inner coils is roughly inversely proportional to the relation of their areas. However, this relation is not fulfilled fully and turns are selected experimentally. Group of coils 3 and 4 is located directly at working end and serves as registering. The other group of pickup loops 5 and 6 is located with axial clearance and serves as compensating. In interaction with continuity defect, being just under turns of one of registering pickup loops 3 and 4, reaction of eddy currents to one of them varies at a large extent that leads to registration of defects in narrow zone and ensures high resolving power of the converter. EFFECT: higher productivity of control due to use of a group of outer coils in the capacity of pickup loops, and inner coils, in the capacity of exciting ones. 9 cl, 4 dwg |
