SIVONIC has published a new Technical Note on the load-dependent detection of hydrogen crossover in PEM and AEM electrolyzers.
Hydrogen crossover affects gas purity, efficiency and operational safety. It may also indicate membrane ageing, local defects or unfavourable operating conditions.
The publication explains how Harmonic Ratio Analysis (HRA) can be used as an electrical early-warning indicator. The ratio of the second harmonic to the fundamental frequency is evaluated across different load points. The key factor is not a single measurement value, but its development over current density, operating time and different cells or cell groups.
Multi-channel measurements are particularly valuable because they can reveal local anomalies that may remain hidden in an overall stack measurement. These include:
- local membrane defects,
- disturbances in water or gas distribution,
- uneven compression,
- abnormal individual cells or cell groups.
HRA does not replace direct gas analysis or safety-related sensor systems. However, it provides a fast additional diagnostic channel for development, test-bench operation and condition monitoring.
The English-language Technical Note by Hannes Benecke and Robert Benecke is available on Zenodo:
Die englischsprachige Technical Note von Hannes Benecke und Robert Benecke ist auf Zenodo veröffentlicht:
![[Translate to Englisch:] SIVONIC_H2-Crossover_mit_HRA_erkennen_2026-07-12](/fileadmin/_processed_/d/e/csm_SIVONIC_H2-Crossover_mit_HRA_erkennen_2026-07-12_a83e74f18a.png)