Abstract: Embodiments herein describe methods, devices, and systems for rupture detection and end-of-life monitoring of dynamic gas lock (DGL) membranes and pupil facet mirrors in lithographic apparatuses. A method for detecting rupture of a dynamic gas lock membrane in a lithographic apparatus includes illuminating the dynamic gas lock membrane with a measurement beam using a radiation source, in which the dynamic gas lock membrane is arranged between a wafer and projection optics of the lithography apparatus, and determining whether any radiation from the measurement beam is reflected from the dynamic gas lock membrane by using reflection collection optics, in which the reflection collection optics are arranged above the dynamic gas lock membrane. A rupture in the dynamic gas lock membrane is detected if no radiation is reflected from the dynamic gas lock membrane. If radiation is reflected from the dynamic gas lock membrane, the dynamic gas lock membrane is not ruptured.