Pressure resistant probe

The probe for monitoring a process standing under pressure in which hazardous substances emerge, comprises a cover (2) with a first window (10) that is in contact with the process area, and a second window (15) that includes a cavity (20) together with the first window and the cover, sealing means (30) that seal the cavity for the process and the environment, and a switching line that is arranged between the first and second window in such a way that the electromagnetic radiation that emerges through one of both windows is conducted over the switching line though the respective other window. The probe for monitoring a process standing under pressure in which hazardous substances emerge, comprises a cover (2) with a first window (10) that is in contact with the process area, and a second window (15) that includes a cavity (20) together with the first window and the cover, sealing means (30) that seal the cavity for the process and the environment, a switching line that is arranged between the first and second window in such a way that the electromagnetic radiation that emerges through one of both windows is conducted over the switching line though the respective other window, a connection for flushing the cavity, a pressure sensor for monitoring the pressure in the cavity or flushing gas supply, a sensor for detecting a material penetrating in the cavity, and a lens for the transmission of electromagnetic radiation over a window. The first window is interchangeable and the second window is integrated in the cover in solid- and pressure-tight manner. The switching line is formed as waveguide or as optical fiber. The probe is formed as process window or immersion probe. The hazardous substance is phosgene. An independent claim is included for a method for monitoring a process standing under pressure. Die Erfindung betrifft eine Sonde zur Überwachung eines unter Druck stehenden Prozesses, sowie ein Verfahren zur Überwachung eines Prozesses, in dem ein oder mehrere Gefahrstoffe auftreten.