At the heart of ultraWAVE 3 is the Single Reaction Chamber (SRC), a stainless-steel reactor with a high-purity PTFE-TFM liner and cover, which serves as both microwave cavity and digestion vessel. Samples and reagents are placed in vials and racks, lowered into the PTFE-TFM liner containing a water-based solution, and then the reactor is closed (1). The water-based load homogenizes the temperature regardless of the sample and acid mixtures in the vials. After the chamber is closed it is pre-pressurised with inert gas to prevent boiling of the reagents, loss of elements, and sample cross-contamination (2). Microwave heating starts and the digestion cycle is continuously controlled in all vials using an advanced contactless temperature sensor (3). An integrated water-cooling circuit maintains the stainless steel chamber at a reduced temperature. At the end of the heating cycle, it promotes rapid cooling of the digestion vials, which is followed by automatic venting of the chamber (4). The reactor is then opened and the digested sample solutions are ready for dilution and analysis.