Film chamber comprising a carrier gas supply, and method for leak testing

A film chamber for leak testing a test specimen containing a test fluid, wherein the film chamber comprises:

• at least one vacuum port connectable to a vacuum pump and to a gas detector;
• at least one flexible wall portion defining a film chamber volume;
• and
• a frame surrounding the flexible wall portion on the outside for closing the film chamber volume, wherein the frame is designed to extend annularly around the flexible wall portion and delimits the flexible wall portion,
• wherein:
• the at least one vacuum port is arranged in an area located centrally with respect to the frame and surrounded radially on the outside by the frame;
• at least one gas inlet for the supply of a carrier gas is arranged in the area of the outer frame such that the carrier gas flows through the gas inlet through the film chamber volume along the flexible wall portion radially from the outside inward to the vacuum port, or
• the at least one gas inlet for the supply of the carrier gas is arranged in an area located centrally with respect to the frame and surrounded radially on the outside by the frame,
• at least one vacuum port is arranged in the area of the outer frame such that the carrier gas flows through the gas inlet through the film chamber volume along the flexible wall portion radially from the inside outward to the vacuum port;
• and
• wherein the gas conductance value in the film chamber volume in the region of the frame is greater in the circumferential direction than the gas conductance value in the radial direction from the gas inlet to the vacuum port.