Chamber for an ionization vacuum gauge

A chamber (11, 12, 13) for bounding a plasma generation area (42) in a vacuum pressure sensor (40), wherein the chamber comprises:

• an electrically conductive casing element (1, 1′, 1″) located radially on outside relative to a central axis (A);
• electrically conductive wall elements (2, 2′, 2″) arranged substantially perpendicular to the central axis and connected to the electrically conductive casing element,
• wherein at least one of the electrically conductive wall elements has a first opening (3), through which the central axis (A) extends wherein the electrically conductive casing element comprises at least a first (B1) and a second region (B2),
• wherein the first region is located closer to the central axis than the second region, and
• wherein a cross-section through the electrically conductive casing element has a shape of a polygon in a plane perpendicular to the central axis.