Real-time detection of non-condensable gas in water vapor systems based on repetitive pulsed discharges for developing <i>in situ</i> probe

High-temperature, high-pressure steam plays a critical role in industrial applications such as sterilization, power generation, and chemical processing. However, the presence of non-condensable gases (NCGs), such as air, can impede heat transfer, lower vapor pressure, and compromise the efficiency of processes like sterilization. This study proposes a novel real-time detection method for NCGs using a discharge-based probe near a cooling area. By monitoring emission intensities of nitrogen gas (a representative NCG) at a benchmark wavelength of 500 nm, the accumulation and release dynamics of NCGs under varying temperature conditions were analyzed. The experimental results demonstrated that the emission intensity trends correlated with NCG concentration difference caused by condensation, validating the probe's ability to effectively detect and quantify NCGs. This approach not only enables precise monitoring of steam purity but also offers insights into collecting the NCGs in steam-based processes for enhanced safety and efficiency.