Using multidifferential transducer for pulsed eddy current object inspection

In this article is considered of experimental results of using the multidifferential type of a transducer at two excitation mode - pulsed and harmonic. The research was carried out on the plates-type samples made of steel and aluminium alloy which had artificial defects like crack. It has been described the analysis procedure signals informative parameters from multidifferential type transducer. The signal amplitude, decrement and frequency of natural oscillations have been used as informative parameters of the transducer signal at the pulsed mode of excitation. The research of multidifferential type of the transducer at harmonic excitation mode was carried out on the frequency which was equivalent to natural oscillations frequency at the pulsed mode of excitation. It is given the experimental results of evaluation of the electric conductivity and cracks depth influence to signal informative parameters. The general character of dependencies of the signal amplitude, decrement and frequency at pulsed mode excitation of the transducer from crack depth in testing samples are found. Also, sensitivities of the signals informative parameters of multidifferential type transducer at both excitation modes to crack depth variation have been defined.