Application Cases

Experiment Name: Application of Power Amplifier in Research on Migration Characteristics of Chloride Ions in Mortar under Stray Current

Experimental Equipment: Waveform generator, ATA-4012 high-voltage power amplifier, data logger, sodium chloride solution, experimental cell.

Experimental Content: Based on the stray current signals collected from on-site detection and leakage in subways, a stray current power supply system was simulated and designed in the early stage of the project. Real stray current signals with adjustable amplitude and the same frequency were reproduced in the laboratory, and the migration behavior of chloride ions in concrete under stray current was investigated accordingly.

Experimental Procedure:

1. Setup of the Electromigration Test Device:

The stray signal simulation device designed for this test consisted of a signal generator and a power amplifier. Using a same-frequency design approach, the stray data collected on-site were reproduced in the laboratory. The design principle was as follows: first, the time-history data of the measured stray signal were subjected to computer noise processing and initial amplitude modulation. The processed signal was then imported into the signal generator, which output a stray signal of the same frequency. This output stray signal was fed into a bipolar power supply for secondary amplitude modulation, ultimately producing a stray current with the same frequency as the measured stray signal and adjustable amplitude, which was applied to the test specimen.

Experimental Results:

1. Penetration depth under currents at terminals A and B:

   
   

   
   

2. Chloride ion profile:

Experimental Conclusion:
The chloride ion migration model described in this paper represents a preliminary study of the migration patterns of chloride ions in mortar under stray current effects. The simulation results were generally consistent with the experimental results, though further research and optimization are required to improve model accuracy. Additionally, the chloride ion migration model should consider the influence of different parameters and account for the use of concrete in future studies.

Figure: ATA-4012C High-Voltage Power Amplifier Specifications and Parameters