Influence of excitation current characteristics on sensor sensitivity of permeability testing technology based on constant current source

摘要

The permeability testing technology is a kind of non-destructive testing method, which based on the change of permeability, can detect the stress concentration state and the degree of fatigue damage for ferromagnetic samples. The detection sensor based on the constant current source has higher detection sensitivity, which overcomes the current negative feedback effect caused by the change of the magnetic circuit impedance of the ordinary constant voltage source. According to the principle of permeability detection, the influence of excitation current frequency, excitation current amplitude on the detection sensitivity were studied. The study shows that the detection sensitivity is related to excitation frequency, which exists extremes with the changing relationship of frequency; The detection sensitivity increases with the increase of excitation current, and shows a linear relationship. The research can provide reference for the development of high sensitivity magnetic permeability detector.