Power amplifier based solid-state magnetic field sensor for pulsed eddy current applications

Experiment name: Application of power amplifier in solid-state magnetic field sensor pulse eddy current detection of corrosion defects in ferromagnetic components

Purpose of the experiment: Through analytical modeling simulation and experiments, it is found that compared with traditional induced voltage signals, magnetic field signals are more sensitive to the depth of corrosion defects in ferromagnetic components, which is beneficial to improving the detection rate and evaluation accuracy of corrosion defects in ferromagnetic components.

Experimental equipment: signal generator, ATA-4014 power amplifier, probe, sensor power supply, data acquisition card, filter amplifier, PC.

Experimental content: To explore the pulse eddy current detection of corrosion defects in ferromagnetic components based on magnetic field measurement, a tunnel magnetoresistance (TMR) sensor is used to pick up the transient magnetic field signal of pulse eddy current detection. Through analytical modeling simulation and experiments, the response sensitivity of the magnetic field signal and the induced voltage signal and their characteristics to the thinning of the thickness of the ferromagnetic components is deeply analyzed and compared.

Experimental process:

The detection probe is composed of an excitation coil, a disc detection coil and a TMR sensor, and its related parameters are consistent with the simulation input parameters. The arbitrary waveform/function signal generator generates a pulse square wave signal, which is amplified by a power amplifier (ATA-4014) and drives the excitation coil. The induced voltage signal and magnetic field signal output by the disc detection coil and the TMR sensor are amplified and filtered by the power amplifier, collected by the data acquisition, and analyzed and processed in real time using the LabVIEW program.

Pulsed eddy current test system block diagram

Experimental results:

Through simulation and experimental results, it is found that compared with the pulse eddy current detection of ferromagnetic components based on disk detection coils, the use of solid-state magnetic field sensors to pick up pulse eddy current detection magnetic field signals can effectively improve the response sensitivity of the detection signal and its characteristics to the thickness reduction/corrosion defect depth of ferromagnetic components, which is beneficial to the improvement of the detection rate and quantitative evaluation accuracy of corrosion defects in ferromagnetic components.