Application Cases

Experiment Name: Application of Power Amplifier in Pulsed Eddy Current Testing of Corrosion Defects in Ferromagnetic Components Using Solid-State Magnetic Field Sensors

Experiment Objective: Through analytical modeling, simulation, and experimental testing, it was found that compared to traditional induced voltage signals, magnetic field signals are more sensitive to the depth of corrosion defects in ferromagnetic components. This enhances the detection rate and evaluation accuracy of corrosion defects in such components.

Experimental Equipment: Signal generator, ATA-4014 high-voltage power amplifier, probe, sensor power supply, data acquisition card, filter amplifier, PC.

Experimental Content: Investigation of pulsed eddy current testing for corrosion defects in ferromagnetic components based on magnetic field measurement. Tunnel magnetoresistance (TMR) sensors were used to capture transient magnetic field signals in pulsed eddy current testing. Through analytical modeling, simulation, and experiments, the response sensitivity of magnetic field signals and induced voltage signals, along with their features, to thickness reduction in ferromagnetic components was deeply analyzed and compared.

Experimental Procedure:
The detection probe consisted of an excitation coil, a disk-type pick-up coil, and a TMR sensor, with parameters consistent with the simulation inputs. An arbitrary waveform/function signal generator produced pulsed square wave signals, which were amplified by the power amplifier (ATA-4014) to drive the excitation coil. The induced voltage signals from the disk-type pick-up coil and the magnetic field signals from the TMR sensor were amplified and filtered by the power amplifier, then acquired by the data acquisition system and analyzed in real time using a LabVIEW program.

Figure: Block Diagram of the Pulsed Eddy Current Testing System

Experimental Results:

Through simulation and experimental results, it was found that compared to pulsed eddy current testing of ferromagnetic components using disk-type pick-up coils, employing solid-state magnetic field sensors to capture magnetic field signals in pulsed eddy current testing effectively improves the response sensitivity of the detection signals and their features to thickness reduction/corrosion defect depth in ferromagnetic components. This is beneficial for enhancing the detection rate and quantitative evaluation accuracy of corrosion defects in ferromagnetic components.

Figure: ATA-4014C High-Voltage Power Amplifier Specifications and Parameters