Improving quality control and productivity of vacuum heat treatment by means of residual gas analysis by remote plasma emission monitoring

Maintaining vacuum integrity is critical for process quality and productivity, as leaks or outgassing can introduce contamination. Residual gas analysis (RGA), commonly conducted with quadrupole mass spectrometers, effectively detects contamination but involves fragile instruments requiring careful operation and frequent maintenance, limiting their practical use in heat treatment equipment.

In this contribution we report on a method based on an alternative gas sensing technology; remote plasma optical emission spectroscopy (RPOES). This technique leverages plasma-induced light emission to detect trace gases present within a vacuum. It also offers greater robustness, an ability to operate at higher pressures and reduces maintenance requirements compared to traditional mass spectrometry gas detection. We will discuss the principles of RPOES, its advantages in detecting specific gases commonly associated with problems in vacuum systems (such as water vapor and air), and its viability as a method to provide smarter AI based process sensing. We will present case studies demonstrating the effectiveness of this technology in identifying vacuum leaks and contamination in various applications, leading to improved process stability, enhanced quality, and reduced operational costs.