Testing device having a test gas container

Abstract

A testing device includes a test gas container, which is provided with a test leak for producing a test gas flow at a predefined leakage rate. The test leak includes at least one capillary tube, which connects the interior of the test gas container to the outer surroundings of the test gas container in a gas-conducting manner. The test gas container is at least partially made of a flexible material.

Claims

1. A testing device for testing the functionality of a leak testing system which subjects a hollow body under test to a defined differential pressure or to a defined pressure for a predetermined period of time, said testing device comprising a test gas container having a test leak for producing a test gas flow with a predefined leakage rate, wherein the test leak comprises at least one capillary tube which connects an interior of the test gas container to an ambient environment of the test gas container in a gas-conducting manner, wherein the test gas container is at least partially made of a flexible material.

2. The testing device of claim 1, wherein the test gas container is a bag entirely made of a flexible material.

3. The testing device of claim 2, wherein the bag is formed by two films joined in a gas-tight manner at their edge portions, the at least one capillary tube being embedded in the edge portion of the films.

4. The testing device of claim 1, wherein the test gas container comprises a spacer in its interior, wherein the spacer is configured to space a part of the flexible material apart from at least a part of the other walls of the test gas container.

5. The testing device of claim 4, wherein the spacer is formed by a flexible soft material.

6. The testing device of claim 1, wherein the length and the inner diameter of the at least one capillary tube are selected such that the resulting leakage rate q of the at least one capillary tube is greater or equal to 10.sup.3 mbar.Math.l/s.

7. The testing device of claim 1, wherein the inner volume of the test gas container is between 100 and 500 cm.sup.3.

8. The testing device of claim 1, wherein the inner volume of the test gas container is between 150 and 250 cm.sup.3.

9. A method for testing the functionality of a leak testing system that subjects a hollow body under test to a defined differential pressure or to a defined pressure for a predetermined period of time, the method comprising a step of simulating a hollow body under test by a testing device, the hollow body comprising a test gas container having a test leak for producing a test gas flow with a predefined leakage rate, wherein the test leak comprises at least one capillary tube which connects an interior of the test gas container to an ambient environment of the test gas container in a gas conducting manner and the test gas container is at least partially made of a flexible material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The following is a detailed description of an embodiment of the invention with reference to the drawings. In the Figures:

(2) FIG. 1 is a longitudinal section through the testing device, and

(3) FIG. 2 is a cross section through the testing device along line II-II in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(4) The testing device 10 of the embodiment comprises a test gas container 12 in the form of a film bag. The test gas container 12 is formed by two flat films 14, 16 which are placed one upon the other and are welded to each other in their outer edge portion 18. The test gas container 12 thus encloses an interior 20 which is separated by the films from the ambient environment 22 of the test gas container.

(5) In the edge portion 18, the test leak 24 is provided in the form of a capillary tube that connects the interior 20 with the ambient environment 22 in a gas-conducting manner. Here, the conduction of gas occurs exclusively from the interior 20 to the ambient environment 22 via the capillary tube. The length of the capillary tube is great relative to the inner diameter thereof.

(6) A spacer 26 in the form of a flexible soft cloth is interposed in the interior 20 between the two films 14, 16. The spacer 26 prevents the two films 14, 16 from sticking on each other in the emptied state of the test gas container 12. Thereby, filling an empty test gas container 12 is facilitated.

(7) When filling the test gas container 12, first, one of the two films 14, 16 is punctured and filled with test gas via the hole thus made. After the filling, the hole made is closed using an adhesive tape or an adhesive. As an alternative, it is also conceivable to provide one of the two films with a sealable opening.

(8) The internal pressure of such a test gas container in the form of a film bag largely corresponds to the external atmospheric pressure. When the amount of gas in the test gas container 12 decreases, the volume of the container adjusts itself correspondingly. Thereby, the leakage rate of the testing device 10 is relatively constant for a comparatively long period of time. With a test gas container 12 having an inner volume of 200 cm.sup.3 and a leakage rate of 10.sup.3 mbar.Math.l/s, it is possible to perform 20,000 calibration processes, the duration of each calibration to be made being 10 seconds.