D. de Cos

Magnetosensitive transducers for nondestructive testing operating on the basis of the giant magnetoimpedance effect: A review

Experimental data on and model representations of the physical processes in small detectors operating on the basis of the magnetoimpedance effect are analyzed and generalized for conditions adapted to systems of magnetic nondestructive testing. The principles of measuring the high-frequency magnetoimpedance effect in electronic circuits including a sensitive element of a detector of weak magnetic fields are briefly described. The data on the available devices for nondestructive testing (NDT) based on the magnetoimpedance effect are systematized and examples of typical approaches are presented.

Selectable temperature sensitivity of the magnetoelastic resonance

The variation of the magnetoelastic resonance frequency as a function of the temperature is investigated for sensing purposes in two samples with different properties. It is observed that maximum sensitivity is reached when biasing the sample close to the anisotropy field. A compensation field is also found at which the resonance frequency is insensitive to temperature changes. It is demonstrated that the observed behavior is determined mainly by the temperature dependence of the anisotropy constants of the samples. The results suggest the viability of remote temperature monitoring even trough opaque barriers.