EP1924803A2

EP1924803A2 - Method and apparatus for testing a gas capsule

Info

Publication number: EP1924803A2
Application number: EP06794540A
Authority: EP
Inventors: Pieter Leopold Timmermans
Original assignee: BOC Group Ltd
Current assignee: BOC Group Ltd
Priority date: 2005-08-23
Filing date: 2006-08-16
Publication date: 2008-05-28
Also published as: WO2007023259A2; CA2618889A1; JP2009506273A; TW200716903A; WO2007023259A3; CN101248307A; GB0517269D0

Abstract

A method is provided for determining whether a pressure within a capsule is at or above a predetermined value. The capsule to be tested is of the type having a movable sealing element acting as a temporary seal to prevent leakage of gas from a mouth of the capsule. The capsule is connected to a plenum, the pressure of which is subsequently elevated. As the capsule is exposed to this elevated pressure, the pressure within the plenum is monitored. From this monitored pressure, it can be determined whether the sealing element is in sealing contact with the capsule under the elevated pressure. This, in turn, indicates whether the pressure within the capsule is at or above the predetermined value.

Description

METHOD AND APPARATUS FOR TESTING A GAS CAPSULE

This invention relates to the testing of gas capsules. The invention finds application in the testing of gas capsules filled at relatively high pressure. Such gas capsules are typically used to dispense a carrier gas for delivering small predetermined doses of a substance to an end point of use. In medical applications the substance may be a drug and the end point of use may be the skin of patient. However, other applications also use such gas capsules, for example test procedures in industrial applications.

Gas capsules of this type, together with a method for filling such capsules, are described in WO 2004/063622. In production of capsules of this type, a capsule typically undergoes a series of processes, two of these processes being (i) filling the capsule through a mouth of the capsule, for example with a high pressure gas such as helium in a cylinder intended for a medical application, and (ii) subsequently forming a permanent seal to close the mouth of the capsule to prevent escape of the high pressure gas. These two processes are typically carried out at separate locations within a production line. A temporary, movable sealing element is used to prevent the pressurised contents of the capsule escaping during transfer of the capsule from a filling station to a welding station for forming the permanent seal.

A capsule is usually formed from at least a body portion and a stemmed cap portion assembled in a fluid tight manner. Circumstances may arise that lead to the assembly of these portions being incomplete so that a fluid tight seal is not achieved between the components. Upon filling the capsule with a pressurised gas, leakage of the gas from the capsule may occur as the pressure within the capsule equalises with the ambient pressure of the atmosphere in which the capsule is located. The pressure within the capsule is consequently reduced, typically to a value of approximately 1 bar. Alternatively it is possible that the filling station may malfunction such that the gas capsule is incorrectly filled or, indeed, not filled at all. In either of these circumstances, the capsule is typically still conveyed to the welding station at

i which location the mouth of the capsule is sealed shut. Consequently, it is possible for defective capsules to be produced. When a defective capsule is incorporated into a delivery device by an end user, attempted delivery of a payload, such as a dose of a drug, fails and the payload may be wasted. It is therefore desirable to be able to check whether a gas capsule has been successfully filled and has retained its contents prior to the permanent closure of the capsule.

According to a first aspect of the present invention there is provided a method for determining whether a pressure within a capsule is at least a predetermined value, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the method comprising the steps of: connecting the capsule to a plenum; elevating the pressure within the plenum towards the predetermined value to exert a force on the sealing element; monitoring the pressure within the plenum; and from the monitored pressure, determining whether the pressure within the capsule is at least the predetermined value.

By testing a capsule in this way, a force is exerted on the movable sealing element by the pressure within the plenum. By monitoring the pressure within the plenum, it can be determined whether the movable sealing element is being held in place by a pressurised content within the gas capsule. This can indicate whether the capsule has been adequately filled and has retained its contents. This additional confidence in the quality of the production of the gas capsules can enhance the confidence in the successful operation of the delivery device in which the gas capsule is ultimately incorporated.

The plenum may be provided by a chamber, a conduit or any other enclosure within which the pressure may be elevated. A seal may be formed between an inlet of the plenum and the capsule, so that gas having a pressure elevated above atmospheric pressure may be retained within the plenum. This seal may be formed between the inlet of the plenum and a stem of the capsule, or between the inlet of the plenum and a body of the capsule. Elevation of the pressure within the plenum may be achieved by introducing a pressurised gas into the plenum, and/or by reducing the volume of the plenum to thereby compress the gas contained therein. The volume of the plenum may be reduced by a predetermined amount, and this reduction in the volume of the plenum may be achieved by displacing a piston located within the plenum.

The monitored pressure within the plenum may be compared to the predetermined pressure to establish whether the pressure within the capsule is at or above the predetermined value. If it is established that the pressure within the capsule is below the predetermined value then the capsule can be rejected. In addition, or alternatively, if it is established that the monitored pressure within the plenum rises above the predetermined value, then the capsule may be rejected as a rise in the monitored pressure value suggests that high pressure gas is leaking from the capsule to the plenum.

According to a second aspect of the present invention there is provided a method for determining whether a pressure within a capsule is at least a predetermined value, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the sealing element having an internal surface to which a first pressure is applied by the gaseous contents of the capsule, and an external surface to which a second pressure is applied by an ambient atmosphere through the mouth of the capsule, the method comprising the steps of: elevating the second pressure towards the predetermined value; monitoring the second pressure; and from the monitored pressure, determining whether the first pressure exceeds the elevated second pressure. A method of testing whether a gas capsule contains a predetermined amount of gas may also be provided, by using one of the aforementioned methods to determine whether a pressure within the capsule is at or above a predetermined value.

According to a third aspect of the present invention there is provided apparatus for testing that a gas capsule contains a predetermined amount of gas, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the apparatus comprising: a plenum having an inlet connectable to a capsule to be tested such that a mouth of the capsule is in fluid communication with the plenum; means for elevating a pressure within the plenum; means for monitoring the pressure within the plenum; and means for determining, from the monitored pressure, whether the gas capsule contains the predetermined amount of gas.

An inlet of the plenum may be configured to receive either a body or a stem of the received capsule. The monitoring means may comprise a sensor for monitoring the pressure within the plenum and outputting signals indicative of the pressure within the plenum. The apparatus may comprise a controller for receiving signals from the sensor. This controller may control the pressure elevation within the plenum, and determine whether the gas capsule contains the predetermined amount of gas. Alternatively, individual controllers may perform these functions.

The means for elevating the pressure may comprise a source of pressurised gas and/or means for reducing the effective volume of the plenum such that the gas contained therein is compressed. The apparatus may be configured such that the effective volume is reduced by a predetermined amount corresponding to a predetermined pressure increase. The means for reducing the effective volume of the plenum may comprise a piston located within the plenum. Alternatively, the means for elevating the pressure may comprise means for reducing the effective volume of a chamber connected to the plenum. The chamber may comprise a moveable piston arranged to be displaced within the chamber to reduce the effective volume thereof.

The plenum may be one of a plurality of plena, each plenum having an inlet connectable to a respective capsule such that a mouth of the capsule is in fluid communication with the plenum and, associated therewith, means for monitoring the pressure within the plenum.

In a fourth aspect, the present invention provides apparatus for filling and sealing gas capsules of the type having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the apparatus comprising: means for filling a gas capsule; apparatus as aforementioned for testing whether the filled gas capsule contains a predetermined amount of gas; means for rejecting a tested gas capsule that does not contain the predetermined amount of gas; and means for permanently sealing a mouth of a tested gas capsule that contains at least the predetermined amount of gas.

Features described above in relation to any of the first and second aspects may be equally applied to any of the third and fourth aspects, and vice versa.

The invention is described below in greater detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 illustrates one embodiment of an apparatus for testing a gas capsule;

Figure 2 illustrates a schematic representation of a process for manufacturing gas capsules;

Figure 3 illustrates a close up view of a stem of a capsule to be tested;

Figure 4 represents a number of pressure traces which may occur during testing of a gas capsule; Figure 5 illustrates a second embodiment of an apparatus for testing a gas capsule; and

Figure 6 illustrates a third embodiment of an apparatus for testing a gas capsule.

Figure 1 illustrates a first embodiment of an apparatus 10 for testing that a gas capsule 15 contains a predetermined amount of gas, the capsule 15 being of the type having a movable sealing element 60 acting to prevent leakage from a mouth 65 of the capsule 15. The apparatus 10 comprises a plenum 20 having an inlet 25 formed in a wall 30 of the plenum 20. The plenum 20 further comprises a moveable piston 35 which acts in combination with the walls 30 of the plenum to vary the volume of the plenum 20. Such variation in volume is controlled by controller 40 which may follow a predetermined sequence or, alternatively, may cause changes in volume dependent on monitored parameters. For example, the pressure within the plenum 20 can be monitored by the controller 40 via a sensor 45 positioned within the plenum 20 for outputting to the controller 40 signals indicative of the pressure within the plenum 20, in response to which the controller 40 controls movement of the piston 35 within the plenum 20.

The capsule 15 is of conventional configuration having a body 50 and a stem 55 arranged to be separated from one another in order to release a pressurised gas therefrom. Figure 2 illustrates, in schematic form, apparatus 100 for manufacturing capsules 15 of this type. The capsules 15 are initially constructed, in a construction station 110, from a number of components to form a body 50 and stem 55 of the capsule 15. In one particular technique of manufacture described in WO 2004/063622, the contents of which are herein incorporated by reference, a dimension of the movable sealing element 60 is larger than the corresponding dimension of the mouth 65 of the capsule 15. The sealing element 60, typically an elastomeric sphere, is therefore placed within the body 50 of the capsule 15 before the stem 55 is connected to the body 50 of the capsule. The capsule 15 is then conveyed to a filling station 120 to be filled with a pressurised gas. The capsule 15 is filled with the pressurised gas and the capsule 15 is subsequently inverted so that the sealing element 60 falls, under gravity, into the stem 55 of the capsule 15. The stem 55 may be tapered as illustrated in more detail in Figure 3, or it may comprise a shoulder to prevent the sealing element 60 from passing through the mouth 65 of the stem 15 and being lost. Consequently, the sealing element 60 is seated against this taper or shoulder to effect a sealing contact with the capsule 15 to prevent the pressurised gas from leaking out of the capsule 15.

In an alternative arrangement (not shown), the sealing element 60 may have a diameter larger than that of the stem 55 so that the sealing element 60 becomes seated within the body 50 of the capsule 15 at the interface between the body 50 and the stem 55 to form a seal to prevent any leakage of gas from the capsule 15.

During filling of the capsule 15 in the filling station 120, a high pressure gas source is applied to the mouth 65 of the stem 55. After the filling step is complete, contact with the high pressure gas source is maintained until the sealing element 60 is appropriately seated as discussed above. When the sealing element 60 is in place, the high pressure gas source is removed.

Opposing surfaces of the sealing element 60 therefore experience a different load, as illustrated in Figure 3. An internal surface 70 experiences a distributed load 72 due to the pressurised gas stored within the capsule 15, whereas an external surface 75 experiences a distributed load 77 due to the ambient atmosphere in which the capsule 15 is located. If the capsule has been correctly filled the load 77 acting on the external surface 75 is lower than the load 72 acting on the internal surface 70. This difference in loading causes the sealing element 60 to be driven into its seat to further enhance the seal formed therebetween. The sealing element 60 forms a temporary seal which, whilst preventing immediate loss of gas from the capsule, is not generally relied upon to form a permanent seal. Returning to Figure 2, the capsule 15 is, therefore, conveyed to a sealing station 140 at which location the mouth 65 of the capsule 15 is welded shut to form a permanent seal. The sealing process may comprise one or more crimping procedures along the stem 55 prior to or in combination with the welding step.

If, for some reason, either the filling procedure fails and the capsule 15 is not filled with high pressure gas or the connection between the body 50 and the stem 55 is incomplete thereby creating a leak path therebetween, an empty or low pressure capsule 15 may result. If such a defective capsule is subsequently used in a delivery device, the delivery procedure will fail, potentially resulting in loss of the dose of substance to be delivered. It is therefore desirable to introduce a testing step between the filling step and the step of forming a permanent seal to determine that the capsule 15 contains at least a predetermined amount of gas. A testing station 130 comprising apparatus 10 is therefore provided between the filling station 120 and the sealing station 140. If a capsule 15 fails the test procedure in the testing station 130 it is not conveyed to the subsequent sealing station 140 but rather is rejected, as indicated at 150 in Figure 2, generally to be discarded.

The apparatus of Figure 1 is used in the following manner. A gas capsule 15 to be tested is inserted into the inlet 25 of the plenum 20 such that a fluid tight seal is formed between the capsule 15 and the plenum 20. In other words, a connection is formed between the capsule and the inlet 25 of the plenum. In the illustrated example, the seal or connection is formed between the stem 55 and the wall 30 of the plenum 20. However, the seal could be formed between the inlet 25 and the body 50 of the capsule 15, so long as the mouth 65 of the stem 55 protrudes into the plenum 20. By forming such a connection between the capsule and the plenum, capsules can be inserted into the plenum and withdrawn again in rapid succession thus enhancing the speed of the testing procedure.

The pressure within the plenum 20 is subsequently raised to increase the load 77 on the external surface 75 of the movable sealing element 60. In this example, the pressure within the plenum 20 is raised by reducing the volume of the plenum 20 to compress the gas contained therein. This reduction in volume is effected by displacing the piston 35 along the length of the plenum 20. The piston may be actuated in response to an instruction issued by the controller 40 which causes rotation of a motor (not shown) which, in turn, drives a gearing mechanism (also not shown) that effects the displacement of the piston 35 within the plenum 20.

Gas capsules 15 may be filled with gas at pressures of between 10 bar and 200 bar depending on the particular application for which they are to be used. Preferably, they are filled with gas at pressures of between 10 bar and 100 bar and more preferably, they are filled with gas at pressures of between 10 bar and 60 bar. Example predetermined pressures are between 2 bar and 10 bar, however a predetermined pressure equivalent to the anticipated content of the capsule 15 could be used to ensure the correct fill pressure has been achieved and maintained.

As the pressure within the plenum 20 is elevated, the load 77 exerted on the external surface 75 of the sealing element 60 is increased. In the event that the capsule 15 contains the anticipated amount of gas, this increased load 77 is more than balanced by the load 72 exerted on the internal surface 70 by the high pressure gas contained within the capsule 15. However, if the fill procedure failed in some way or a leaky capsule was generated, the capsule 15 does not contain the anticipated high pressure gas and the load 72 exerted on the internal surface 70 is reduced. In the event that the sealing element 60 is located within the stem 55 it may be retained within the stem 55 by means of a friction force acting at the interface between the stem 55 and the sealing element 60. The friction force and the load 72 acting on the internal surface 70 are overcome by the elevated load 77 exerted on the external surface 75 as a result of the elevated pressure of the gas within the plenum. In this circumstance, the seal element 60 is dislodged from the stem 55 and drops into the body 50 of the capsule 15. Preferably, the elevation in pressure is effected rapidly, for example taking only a few milliseconds, such that an impulse is imparted to the sealing element 60. Such an impulse will further encourage any sealing element 60 held merely by friction to be dislodged from within the stem 55.

Once the seal is broken the volume of the plenum 20 is effectively increased in magnitude by the volume of the capsule 15 and pressure equalisation takes place throughout the new, increased volume so that the pressure within the plenum 20 falls.

Throughout this sequence, the pressure within the plenum 20 is monitored by the sensor 45 in combination with the controller 40. If the initial, ambient pressure within the plenum 20 is P_amb, reduction of the volume of plenum 20 results in a predictable and predetermined pressure increase to an elevated pressure, P_test- The graph of Figure 4 illustrates the variation in pressure within the plenum 20 for different potential capsule filling scenarios.

The first pressure trace (i) is indicative of a capsule 15 which has been correctly filled and has retained its contents. The pressure within the capsule, P_capsuie, is greater than the test pressure Ptes_t and so the sealing element 60 remains in place. The anticipated elevated pressure within the plenum, P_test is not only achieved but is also maintained over the duration of the test.

The second pressure trace (ii) is indicative of a capsule 15 which has been incorrectly filled or has leaked its contents. P_capsui_e is approximately the same as P_amb i.e. lower than the test pressure P_test and so the sealing element 60 is dislodged as the pressure within the plenum 20 is elevated towards P_test which causes the seal between the plenum 20 and the capsule 15 to be broken. Upon breach of this seal the volume of the plenum 20 is effectively increased by the additional volume of the capsule 15 and the pressure within the plenum 20 reduces to P_eq.

In some instances when the capsule 15 has not been correctly filled or the contents have been completely lost, the sealing element 60 is not even located within the stem 55 and so P_capsuie is equal to P_ambfrom the outset. This scenario is represented by pressure trace (iii). The initial effective volume of the plenum 20 thereby includes the volume of the capsule 15, and so the reduction in volume of the plenum 20 by displacement of the piston 35 results in a slight, continuous increase in pressure to P_eq> but P_tΘSt is not achieved.

Monitoring of the pressure within the plenum 20 using sensor 45 enables the different pressure traces to be detected so that the fill status of the capsule 15 can be determined.

As discussed above, if a defective capsule 15 is detected, it can be rejected prior to undertaking the permanent sealing step to thereby improve the quality of capsules 15 leaving the manufacturing process and consequently the reliability of the finished product.

Figure 5 illustrates an alternative piston 35 and plenum 20 configuration. A piston 35 is located in a chamber 80 positioned remotely from the plenum 20 and connected thereto by a conduit 85 via one way valve 90. It is desirable for the volume of plenum 20 to be kept to a minimum so that any pressure fluctuation experienced within the plenum is more readily detected by sensor 45. Were the plenum 20 in the apparatus shown in Figure 1 to be of small volume such that sensitivity to pressure fluctuations were achieved, it would be difficult to significantly increase the pressure in the plenum 20 by displacement of a piston 35. By positioning the piston 35 in a separate chamber 80 a larger volume can be used so that an increased change in pressure can be effected. One way valve 90 permits the high pressure gas to be passed to the plenum 20 through conduit 85, whilst inhibiting flow of the gas back into conduit 85 so that a restricted volume plenum 20 can be maintained.

An additional advantage of using a remote chamber 80 is that a number of conduits 85 may be provided to a corresponding number of plena 20 each configured to test an individual capsule 15. Banks of ten such plena 20 may be provided to test a batch of ten gas capsules 15 in any one testing procedure.

Other means of providing a pressure increase may be used. One such alternative is illustrated in Figure 6 in which a high pressure gas source 95 is provided in selectable fluid communication with plenum 20 via conduit 85 and valve 100. When the pressure within plenum 20 is to be elevated, the controller 40 causes valve 100 to be opened to enable high pressure gas to pass into plenum 20 to increase the pressure therein. As in the configuration illustrated in Figure 5 any number of conduits 85 can be provided to a corresponding number of plena 20 to enable each to simultaneously test a respective capsule 15.

An alternative mode of failure for the capsule 15 may result from a defective sealing element 60. The sealing element 60 may be cracked, or fail to seat correctly in relation to the stem 55. In these circumstances the temporary seal will be incomplete and a leak path will be formed. If this leak path is significant, the pressure within the capsule reduces below the predetermined value and the capsule 15 is rejected by the aforementioned testing technique. On the other hand, if the leak path is minimal the pressure within the capsule reduces substantially to create a defective capsule but the pressure may remain above the predetermined value and hence the capsule 15 will pass the aforementioned test and be forwarded to the sealing station 140 to be permanently sealed. In order to detect this mode of failure an elevated predetermined value of pressure may be used to confirm that the actual pressure within the capsule 15 is at the required value. However, there are disadvantages associated with this approach. Firstly, to elevate the pressure within plenum 20 to this significantly higher value takes a considerably larger volume to be compressed by the piston or a considerably larger quantity of gas to be introduced into the plenum leading to increased costs and potentially a larger footprint of the apparatus. Secondly, additional time is required to elevate the pressure to the significantly higher value thus increasing the testing time for each capsule. For these reasons increasing the predetermined value is not a particularly desirable course of action.

In a further embodiment of an apparatus for testing that a gas capsule 15 contains a predetermined amount of gas, the monitored pressure within the plenum 20 can be used to detect a failure mode involving a minor leak through or around a defective sealing element 60. Returning to Figure 4, the fourth pressure trace (iv) is indicative of a defective capsule having a leak path through, or around, the sealing element 60. In other words, the leaking gas is passing through the mouth 65 of the capsule 15. P_cap_sui_e, in this instance, is greater than P_test and so sealing element 60 is not dislodged. However, additional gas passes from the capsule 15 through the mouth 65 of the capsule 15 into the plenum 20, causing the pressure within the plenum 20 to be raised above P_test- This further elevated pressure can be detected by sensor 45 to enable the defective capsule 15 to be rejected prior to being conveyed to the sealing station 140 to be permanently sealed.

Claims

1. A method for determining whether a pressure within a capsule is at least a predetermined value, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the method comprising the steps of: connecting the capsule to a plenum; elevating the pressure within the plenum towards the predetermined value to exert a force on the sealing element; monitoring the pressure within the plenum; and from the monitored pressure, determining whether the pressure within the capsule is at least the predetermined value.

2. A method according to Claim 1 , wherein a seal is formed between an inlet of the plenum and the capsule in the connecting step.

3. A method according to Claim 2, wherein the seal is formed between the inlet of the plenum and a stem of the capsule.

4. A method according to Claim 2, wherein the seal is formed between the inlet of the plenum and a body of the capsule.

5. A method according to any preceding claim, wherein the elevating step comprises introducing gas from a pressurised gas source into the plenum.

6. A method according to any preceding claim, wherein the elevating step comprises reducing a volume of the plenum by a predetermined amount to compress the gas contained therein.

7. A method according to Claim 6, wherein the volume is reduced by displacing a piston located within the plenum.

8. A method according to any preceding claim, wherein the monitored pressure is compared to the predetermined value in the determining step.

9. A method according to any preceding claim, wherein the capsule is rejected if the pressure within the capsule is determined to be below the predetermined value.

10. A method according to Claim 8, wherein the capsule is rejected if the pressure within the plenum is determined to be above the predetermined value.

11. A method for determining whether a pressure within a capsule is above a predetermined value, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the sealing element having an internal surface, to which a first pressure is applied by the gaseous contents of the capsule, and an external surface, to which a second pressure is applied by an ambient atmosphere through the mouth of the capsule, the method comprising the steps of: elevating the second pressure towards the predetermined value; monitoring the second pressure; and from the monitored pressure, determining whether the first pressure exceeds the elevated second pressure.

12. A method of testing whether a gas capsule contains a predetermined amount of gas, comprising a method according to any preceding claim, for determining whether a pressure within the capsule is at least a predetermined value.

13. Apparatus for testing that a gas capsule contains a predetermined amount of gas, the capsule having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the apparatus comprising: a plenum having an inlet connectable to a capsule to be tested such that a mouth of the capsule is in fluid communication with the plenum; means for elevating a pressure within the plenum; means for monitoring the pressure within the plenum; and means for determining, from the monitored pressure, whether the gas capsule contains the predetermined amount of gas.

14. Apparatus according to Claim 13, wherein an inlet of the plenum is configured to receive a body of the received capsule.

15. Apparatus according to Claim 13, wherein an inlet of the plenum is configured to receive a stem of the received capsule.

16. Apparatus according to any of Claims 13 to 15, wherein the monitoring means comprises a sensor.

17. Apparatus according to any of Claims 13 to 16, wherein the pressure elevation means comprises a source of pressurised gas.

18. Apparatus according to any of Claims 13 to 17, wherein the pressure elevation means comprises means for reducing the effective volume of the plenum by a predetermined amount such that the gas contained therein is compressed by a predetermined amount.

19. Apparatus according to Claim 18, wherein the means for reducing the effective volume of the plenum comprises a piston.

20. Apparatus according to any of Claims 13 to 19, wherein the plenum is one of a plurality of plena, each plenum having an inlet connectable to a respective capsule such that a mouth of the capsule is in fluid communication with the plenum and, associated therewith, means for monitoring the pressure within the plenum.

21. Apparatus for filling gas capsules of the type having a movable sealing element acting to prevent leakage of gas from a mouth of the capsule, the apparatus comprising: means for filling a gas capsule; apparatus according to any of Claims 13 to 20 for testing whether the filled gas capsule contains a predetermined amount of gas; means for rejecting a tested gas capsule that does not contain the predetermined amount of gas; and means for permanently sealing a mouth of a tested gas capsule that contains at least the predetermined amount of gas.