Simultaneous Dissolved Gas Analysis in Transformer Oil via Time-Division-Multiplexed Quartz-Enhanced Photoacoustic Spectroscopy

Dissolved gas analysis (DGA) is an essential method for monitoring and diagnosing faults in oil-immersed transformers. Acetylene (C2H2) and methane (CH4) are key indicator gases for fault identification. We report for the first time a time-division-multiplexed quartz-enhanced photoacoustic spectroscopy (QEPAS) sensing system capable of simultaneously and sensitively detecting dissolved C2H2 and CH4, even with an extremely small amount of required sample gas. The on-beam configuration enhanced the 2f signal amplitude by nearly 20-fold. The sensing system achieved minimum detection limits (MDLs) of approximately 15 ppb for C2H2 and 0.3 ppm for CH4, which are 2–3 orders of magnitude lower than the safety…

• NN
  National Natural Science Foundation of China

  Awards: 62105252, 62475137, 62235010
• NS
  National Science and Technology Major Project

  Award: 2025ZD1200704