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The magnetic flux density in the magnetizing coil during the hysteresis measurement was calculated. The influence of a slot, machined in a ferromagnetic plate was simulated. The size of the magnetizing yoke was changed and the influence of this modification was studied on the detectable flux density. The size of the slot and the thickness of the air gap, which appears between the magnetizing yoke and plate’s surface, was also taken into account. It was found that by this simulation the experimental conditions could be successfully modelled. A sensitivity analysis of the studied nondestructive testing setup was also performed and the impact of different experimental parameters was analyzed. The results of simulation can be used successfully for determining the optimal parameters of the actual measurement arrangement if method Magnetic Adaptive Testing measuring technique (which is based on systematic measurement and evaluation of minor magnetic hysteresis loops) is applied. [ABSTRACT FROM AUTHOR]

Improved eddy current techniques and a method of magnetic hysteresis measurement were applied for nondestructive inspection of thickness of the hardened surface layer of the steel injectors of diesel engines. A monotonic correlation was found with enough sensitivity and acceptable signal/noise ratio between the electromagnetic parameters and the thickness of the layer. Both the hysteresis and the eddy current methods show very similar types of the correlation. Based on these results, practical application of these novel methods can be realized instead of the presently used destructive tests for inspection of the steel injectors of diesel engines. [ABSTRACT FROM AUTHOR]