Method for leak testing and leak testing apparatus
OwnerMartin Lehmanninventor
Life of this patent
Estimating the term…
Abstract
For leak testing closed containers (9) which are filled with a filling product containing at least one liquid component the container is introduced in a test cavity (1) which is evacuated at least down to vapour pressure of that liquid component. The pressure in the surrounding of the container (9) and thus within test cavity (1) is monitored. Monitoring is performed by a vacuum pressure sensor (7), whereas lowering pressure surrounding the container (9) is performed by a vacuum pump (5). Leakage is detected by monitoring a pressure change in the surrounding of the container which is due to evaporation of liquid emerging from a leak and being evaporated in the low pressure surrounding.
Claims39
A method for leak testing at least one closed container, comprising applying a pressure difference across at least a part of the wall of the container, which part is to be leak tested, and monitoring the pressure on one side of said wall over a test time period as a leak indicative signal, and said method including:
- establishing a pressure reference signal;
- generating a dynamic signal range that represent an acceptable change across said part during said test period with respect to the pressure reference signal;
- monitoring whether a signal derived from said pressure monitored is or is not within said dynamic signal range;
- and
- enabling said signal derived from said pressure monitored to update said dynamic signal range, if said signal derived from said pressure monitored is within said dynamic signal range, thereby indicating the container to fulfill a predetermined condition of acceptable pressure change with respect to leakiness.
A method for producing at least one closed, and unleaky container comprising leak testing said container by applying a pressure difference across at least a part of the wall of said container, between the inside of said container and the surrounding of said container, which part is to be leak tested, monitoring the pressure on one side of said part of said wall over a test time period as a leak indicative signal, and wherein said method includes:
- establishing at least one pressure reference signal,
- generating a dynamic signal range that represents an acceptable pressure change across said part during said test period with respect to said at least one pressure reference signal,
- monitoring whether a first signal derived from the pressure monitored is or is not within said dynamic signal range,
- enabling a second signal derived from said pressure monitored to update said dynamic signal range if said first signal derived from said pressure monitored is within said dynamic signal range, thereby indicating the container to fulfil a predetermined condition of acceptable pressure change with respect to unleakiness.
Dependencies are inferred from the claim text.