# US 2019/0376872 A1 · Film chamber having double film

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- Number: US 2019/0376872 A1
- Document ID: US20190376872A1
- Status: Published application
- Kind: A1
- Application number: 16/476,820
- Filed: 2018-01-17
- Published: 2019-12-12
- Earliest claimed: 2017-01-23
- Assignees: Inficon GmbH
- Applicants: INFICON GmbH
- Inventors: Daniel Wetzig
- Web page: https://patentgrep.com/patent/US20190376872A1

## CPC

- G01M 3/3281: {removably mounted in a test cell}
- G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR

## Abstract

The invention relates to a film chamber 10 which has a film chamber wall for testing the sealing tightness of a gas-filled test specimen 38, which film chamber wall defines a chamber volume 32 for holding the test specimen 38 and has a first vacuum connection 28 for evacuating the chamber volume 32 by means of a first vacuum pump 30 connected to the first vacuum connection 28, wherein at least a portion of the film chamber wall has a flexible film 12, 14, characterized in that the film 12, 14 has two layers 20, 22 arranged adjacent to each other which surround an evacuable film interspace 26.

## Claims

### Claim 1

A film chamber comprising a film chamber wall provided for a tightness test on a gas-filled test specimen, said film chamber wall defining a chamber volume for accommodating said test specimen and being provided with a first vacuum connection for evacuating said chamber volume by means of a first vacuum pump connected to said first vacuum connection, wherein at least a portion of the film chamber wall comprises a flexible film and wherein said film comprises two layers arranged adjacent to each other and surrounding an evacuable film interspace,
characterized in that
a second vacuum connection is provided to which a second vacuum pump is connected for evacuating the film interspace.

### Claim 2 (depends on 1)

The film chamber according to claim 1, characterized in that in the film interspace a gas-permeable material separating the two layers from each other is arranged.

### Claim 3 (depends on 2)

The film chamber according to claim 2, characterized in that the gas-permeable material is a nonwoven fabric.

### Claim 4 (depends on 1)

The film chamber according to claim 1, characterized in that the film chamber comprises two adjacent films between which the chamber volume is defined and which are respectively made up of two adjacent layers having respective film interspaces arranged between said two layers.

### Claim 5 (depends on 4)

The film chamber according to claim 4, characterized in that the outer edge area of each film is provided with a frame holding said film and being sealingly connected with said film, wherein said two frames constitute or comprise the first and/or the second vacuum connection.

### Claim 6 (depends on 1)

A method for leakage detection on a test specimen 38 using a film chamber 10 according to claim 1,
characterized by the following steps
introducing said test specimen into the chamber volume,
closing said chamber volume,
evacuating said chamber volume down to a predetermined vacuum pressure below atmospheric pressure,
measuring over time the pressure inside said film chamber in the area outside said test specimen,
detecting an increase of the measured pressure, and
evacuating at least one, and preferable each film interspace during the leakage detection.

### Claim 7 (depends on 6)

The method according to claim 6, characterized in that the film interspace is permanently kept below a limit vacuum pressure during the pressure measurement.