FERROSONDE COERCIVE FORCE METER Russian patent published in 1999 - IPC

FIELD: nondestructive testing of ferromagnetic articles in mechanical engineering and mining metallurgy. SUBSTANCE: ferrosonde coercive force meter has U-shaped magnetic core that carries magnetizing and demagnetizing windings connected to power supply source, demagnetization current meter and ferrosonde. Ferrosonde carries bucking winding that creates magnetic flux opposite to demagnetizing one into which tunable source of bias voltage is additionally brought to diminish error caused by value of gap between tested article and pieces of magnetic core whose output is connected to ferrosonde. Values of constant bias voltage and magnetic flux are chosen with due account of compensation of effect of value of gap on measurement of coercive force in wide measurement range. Technical result of invention lies in provision for high measurement accuracy of coercive force of articles thanks to diminished error in determination of coercive force when value of gap between pole pieces of magnetic core and article varies. Such approach makes it possible to conduct measurement of coercive force of parts with rough surfaces obtained after casting or rolling with little scale or some decarbonization as well as after deep machining and insufficient surface cold working. EFFECT: high measurement accuracy of coercive force of articles. 4 dwg