METHOD OF MAGNETIC POWDER CONTROL AND DEVICE TO THIS END Russian patent published in 2009 - IPC G01N27/84 

FIELD: physics, measurements.

SUBSTANCE: invention relates to flaw inspection and is intended for non-destructive testing of ferromagnetic parts for discontinuity. In compliance with the invention, a magnetising device with indicator package is placed onto the surface of controlled part to act thereon by variable magnetic field. The presence of defects is decided on by visual control over indicator particles arrangement in the indicator package, the image being erased thereafter. Given the defect in the controlled zone, the magnetic fluid electrical resistance is measured with the help of electric contacts fitted in the said indicator package. Note here that the magnetic fluid electrical resistance is, first, made outside the defect zone and, then, in the defect zone by shifting the indicator package and aligning the line of contacts with the defect central plane. The proposed device comprises a power supply, electromagnet, indicator package and flat coil in interpole space, rigidly fixed on electromagnet end faces. Indicator package contains magnetic fluid and is flexibly suspended to the coil lower plane. The said package houses two electric contacts fitted on one axle. Magnetic fluid contains copper powder in the amount of 30 to 50% of magnetic fluid weight.

EFFECT: non-destructive testing of ferromagnetic parts for discontinuity.

4 cl, 4 dwg