Method for detecting a leak on a non-rigid test specimen

1. A method for detecting leaks on a non-rigid test specimen, comprising the steps of:

introducing the test specimen into a film chamber,

lowering the pressure in the film chamber outside of said test specimen, and

detecting a leak in the test specimen on the basis of a spatial change in a film of said film chamber; and

wherein the pressure in the film chamber is reduced to a pressure that is lower than the pressure in the test specimen by at least 500 mbar and preferably by at least 950 mbar.

2. The method of claim 1 , wherein, after the introduction of the test specimen, the closed film chamber shows a leakage rate during detection that is at least as high or at least twice as high as a leakage rate of the test specimen.

3. The method of claim 1 , wherein the spatial change in the film is measured by laser-optical measurement of a position of the film surface.

4. The method of claim 3 , wherein the laser-optical measurement is performed by measuring the change in deflection of a laser directed onto the film surface.

5. The method of claim 1 , wherein the spatial change in the film is detected by measuring the capacitance change of a metalized film surface.

6. The method of claim 1 , wherein the spatial change in the film is detected by means of a device that indicates contact or the absence of contact with the film surface.

7. The method of claim 1 , wherein the leakage rate of a gas escaping through the leak in the test specimen is calculated in dependence on the measured spatial change in the film.

8. The method of claim 1 , wherein the reduction of the pressure in the film chamber is performed while maintaining the atmospheric pressure in the test specimen.