Transformer on-line monitoring and fault diagnosis technology is very important for improving the safety and stability of power system.Among them, on-line monitoring technology based on dissolved gas analysis in oil is the most common and the most important technology in on-line monitoring of transformers. DGA is a powerful diagnostic tool to help you understand the health and condition of power transformers and other oil-filled equipment. Analyzing the composition and content of dissolved gas in oil is one of the most effective measures to monitor the safe operation of oil-filled electrical equipment.DK-200P Portable Dissolved Gas Analyzer using photoacoustic spectroscopy to analyze dissolved gas in oil to monitor the safe operation of oil-filled electrical equipment has the characteristics of accuracy,repeatability,maintenance-free, quick response and high precision.