METHOD DETERMINING MECHANICAL STRESSES IN ARTICLES MADE FROM FERROMAGNETIC MATERIALS AND GEAR TO REALIZE IT Russian patent published in 1999 - IPC

FIELD: nondestructive inspection of quality of articles, tests of welding stresses. SUBSTANCE: converter made up of two mutually perpendicular electromagnets, one being magnetizing, the other one being instrumental, is placed on tested article. Magnetization signal is fed from generator of sinusoidal signal to magnetizing electromagnet. Intermediate value of measured magnitude is determined by way of phase-sensitive measurement of converted signal from instrumental electromagnet by phase-sensitive voltmeter. Effective value of signal from instrumental electromagnet is determined simultaneously with phase-sensitive measurement with the aid of AC voltmeter. Final value of measured magnitude which is used to evaluate mechanical stress in article is found in computer as positive effective value of converted signal if intermediate value of measured magnitude is positive. In other case final value of measured magnitude in computer is assumed to be equal to negative effective value of converted signal. Method provides for determination of measured value without losses when magnetizing and converted signals are out of phase which enhances accuracy of determination of mechanical stresses in article. EFFECT: higher efficiency. 2 cl, 1 dwg, 1 tbl