Sampling lid for particle monitoring system and particle monitoring system comprising such sampling lid

Abstract

The present application relates to a sampling lid for a particle monitoring system, preferably a microbiological gas (for example, air) sampler or airborne particle counter. The present application also relates to a particle monitoring system comprising such sampling lid as well as to a method for a gas monitoring process using such particle monitoring system comprising such sampling lid.

Description

[0001] SAMPLING LID FOR PARTICLE MONITORING SYSTEM AND PARTICLE MONITORING SYSTEM COMPRISING SUCH SAMPLING LID

[0002] Technical Field

[0003] The present application relates to a sampling lid for a particle monitoring system, preferably a microbiological gas (for example, air) sampler or airborne particle counter. The present application also relates to a particle monitoring system comprising such sampling lid as well as to a method for a gas monitoring process using such particle monitoring system comprising such sampling lid.

[0004] Background

[0005] The monitoring of sample fluids, either of liquids or more commonly of gases like air, is frequently performed for the purpose of evaluating contaminants, for classification and monitoring purposes, in a range of cleanroom and manufacturing environments requiring low levels of particles, such as cleanroom environments for electronics manufacturing or semiconductor manufacturing or measuring instruments manufacturing and aseptic environments for manufacturing pharmaceutical and biological products, such as sterile medicinal products.

[0006] Forthe purpose of monitoring fluid (air) in such a context, particle monitoring systems are known and comprise microbial or active gas (air) samplers and particle counters. Microbiological or active gas (air) samplers and airborne particle counters are beneficial because they allow a user to sample a quantitative amount of air and to determine the risk for contamination (microbial flora) to sterile products in a surrounding environment.

[0007] An example of a microbiological air sampler and method for sampling, detecting and / or characterizing particles, for example, via collection, growth, and analysis of viable biological particles such as microorganisms is disclosed in EP 0 964 240 Al. This device includes an integrated sampler and impact surface, such as the receiving surface of a growth media in a Petri-dish, for collecting biological particles. The collected particles are then typically incubated to grow living particles and are then analyzed by different techniques including naked eyes inspection, microscopy, fluorescence or autofluorescence, ATP detection or others. A particle counter as the other type of particle monitoring device typically pumps the gas to be monitored through a measuring system. A laser beam is directed into the gas flow and particles crossing the laser beam will create signals that are detected by a photomultiplier. The output of the photomultiplier has several amplifiers with different gain stages that allow a discrimination of particle number and particle sizing based on the evaluation of the signals, more specifically of the amplitudes of the signals.

[0008] The present application pertains to particle monitoring systems where the sampling section for performing a sampling process on a sample fluid, preferably a gas, such as air, which comprises either a particle collector or a particle counter, or one where the sampling section comprises a combination of a particle collector and a particle counter. The general monitoring procedure and technology of the particle monitoring systems is as such unaffected by the use of a sampling lid as defined herein and hence will not be described in detail.

[0009] US 2021 / 0214121 Al discloses an air sampler device for a particle monitoring system. The air sampler device includes a bottom plate on which a Petri dish is to be placed, and a top plate that is placed on the bottom plate to surround the Petri dish and that is an example of a sampling lid. A vacuum tube is attached to an air port of the bottom plate. Air is then sucked into the sampler device through holes in the top plate, so that the air strikes a test media contained in the Petri dish, which is accommodated inside the air sampler device between the top plate and the bottom plate. The air exits through the air port. At the end of the testing cycle, the top plate (sampling lid) is taken off of the bottom plate, the Petri dish is removed, and the top plate is replaced. The Petri dish can then be analyzed to determine the level of cleanliness of the surrounding environment.

[0010] The entire device disclosed in US 2021 / 0214121 Al is made of metal so that the device can be sterilized by heat, steam, Vaporized Hydrogen Peroxide (VHP) or Ethylene Oxide (ETO). Since the Petri dish has a diameter of about 9 cm (3.5 Inches), the top plate has a slightly larger diameter of 11.5 cm (4.5 Inches) and is thus relatively heavy. Further, the outer surfaces of the top plate are flat and smooth and difficult to grasp by a person inside the clean room who is wearing gloves. US 2021 / 0214121 Al suggests providing the top plate with a concaved sidewall along the outer circumference of the top plate to create a more positive contact between the fingers of the user and the sidewall of the top plate and to achieve an about 20% reduction of the weight of the top plate. This solution is still relatively bulky, heavy and difficult to clean as it requires sophisticated and energy-consuming sterilization equipment like an autoclaving machine which is not available at each site. Externalizing the autoclaving process is costly and requires a considerable stock of material - sterilized and used - to maintain continuous operation.

[0011] Finally, the current sampling lids or top plates of air sampler devices for particle monitoring systems for environmental monitoring are not optimized for a robotic and automated application which is, however, a certain trend in the industry to reduce labour and raise safety and quality standards.

[0012] The present application therefore aims at providing a sampling lid fora particle monitoring system, preferably a microbiological gas (air) sampler or airborne particle counter, that solves at least some of the problems associated with existing solutions.

[0013] Summary

[0014] To solve the above-indicated problems the present application provides for a sampling lid for a particle monitoring system as defined by claim 1, a particle monitoring system as defined by claim 13, and a gas sampling process as defined by claim 14. Preferred embodiments of the sampling lid for a particle monitoring system are defined in the dependent claims.

[0015] Thus, the present application provides for a sampling lid for a particle monitoring system comprising:

[0016] (i) a support section configured to be releasably attached to a sampling section of the particle monitoring system and to define a space surrounding an impacting and collecting surface, preferably a petri dish, placed on the sampling section; and

[0017] (ii) a sieve section supported by the support section to close an open side of the space above the impacting and collecting surface, preferably the petri-dish, the sieve section provided with fluid openings arranged to direct, in operation of the particle monitoring system, a fluid towards the impacting and collecting surface, preferably the petri dish, placed on the sampling section.

[0018] Preferably, the support section and the sieve section are integrally formed, preferably are integrally molded, preferably by injection molding. Preferably, the support section is configured to be moved along a body of the sampling section of the particle monitoring system between a position where it defines the space surrounding the impacting and collecting surface, preferably the petri dish, placed on the sampling section and a position providing access to the sampling section.

[0019] Preferably, the support section is provided with a plurality of radial ribs or protrusions and / or recesses distributed about the periphery thereof to allow gripping of the support section by a gripper implement of a robot for the purpose of positioning it on the sampling section and / or to increase the rigidity against deformation.

[0020] Preferably, the support section comprises a lower skirt portion and an upper skirt portion, the lower skirt portion having a larger diameter than the upper skirt portion such that there is a step-like transition portion between the two.

[0021] Preferably, the ribs are formed as extensions of the lower skirt portion extending onto the upper skirt portion beyond the step-like transition portion.

[0022] Preferably, the lower skirt portion is formed to surround and releasably engage with a peripheral edge of the sampling section.

[0023] Preferably, the support section is a ring-like body.

[0024] Preferably, the sieve section is peripherally surrounded by a peripheral rim of the support section and preferably is axially recessed from a top surface of the peripheral rim of the support section towards the impacting and collecting surface, preferably the petri dish to form a trough-like portion.

[0025] Preferably, the peripheral rim of the support section, on a side facing the sampling section of the particle monitoring system, is formed so as to surround, in the mounted state on the sampling section, a raised outer peripheral wall of the impacting and collecting surface, preferably the petri dish, creating an inverted U- or V-shaped gap through which a fluid can pass from a central region of the space above the impacting and collecting surface and below the sieve section to an outer peripheral region of the space surrounding the impacting and collecting surface, preferably the petri dish.

[0026] Preferably, the sampling lid is configured to be engaged with other sampling lids of the same configuration to form a self-supporting stack. Preferably, the sieve section and / or the support section are / is provided with a data tag containing an identifier, preferably of an electronically readable type.

[0027] Preferably, the sampling lid comprises an impacting and collecting surface, preferably a petri dish.

[0028] The present application also provides for a particle monitoring system comprising the sampling lid as defined above.

[0029] Furthermore, the present application provides for a gas monitoring process comprising the steps of

[0030] (a) providing a petri dish comprising a lid and a bottom;

[0031] (b) placing the petri dish onto a base of a particle monitoring system, and removing the lid of the petri dish;

[0032] (c) positioning a disposable sampling lid as defined herein onto the base, the disposable sampling lid comprising fluid openings of a sieve section; and

[0033] (d) sucking fluid (e.g. a gas or air) through the fluid openings of the sieve section, thereby collecting particles entrained in the stream of fluid on the surface of the petri dish.

[0034] Brief description of the drawings

[0035] The present sampling lid and particle monitoring system will in the following be described in more detail on the basis of a preferred but non-limiting exemplary embodiment by reference to the following attached schematic exemplary drawings:

[0036] Figures la, lb and lc show an embodiment of the sampling lid in a perspective view (Figure la), in a perspective cross-sectional view (Figure lb), and in a sectional elevation view (Figure lc), each in conjunction with a sampling section of a particle monitoring system.

[0037] Figures 2a to 2e show a sequence of characteristic steps of an air monitoring process using the sampling lid according to the embodiment in a perspective view (Figures 2a, 2c, 2d, 2e) and in a perspective cross-sectional view (Figure 2b) each in conjunction with a sampling section of a particle monitoring system. Detailed description

[0038] The sampling lid as described herein is designed as a single use component (preferably made of plastics material) to avoid the need of cleaning and autoclaving before and / or after each use.

[0039] It also reduces the weight of the parts to be handled in that the sampling lid can be made from light plastics material.

[0040] The present sampling lid also provides a compatible air sampling lid solution for both manual and automated use.

[0041] Figures la to lc show an embodiment of the sampling lid 1 as described herein in conjunction with a sampling section 3 of a particle monitoring system (not shown). It is remarked that the sampling section 3 is not part of the present sampling lid but is a component of particle monitoring systems known per se. The sampling lid 1 is in any case designed to be compatible with a respective sampling section 3 to provide the functionalities described below.

[0042] The sampling lid 1 for a particle monitoring system comprises a support section 2 configured to be releasably attached and fixed to the sampling section 3 of the particle monitoring system and to define a space 5 surrounding an impacting and collecting surface, such as a petri dish 4, placed on a base 3a of the sampling section 3 (as described above in conjunction with the prior art). Though in the following, the present sampling lid 1 is to be described with a petri dish 4 as impacting and collecting surface, it is to be understood that, instead of a petri dish, any impacting and collecting surface may be used.

[0043] A petri dish generally comprises a bottom and a lid, wherein the bottom preferably comprises a growth medium.

[0044] The sampling lid 1 also comprises a sieve section 6 integrally formed with the support section 2 and configured to close an open side of the space 5 above the petri-dish 4. The sieve section 6 is provided with an array of fluid openings 7 (which may in this application also be referred to as "holes") arranged to direct, in operation of the particle monitoring system, a fluid that may support bacteria contaminants towards a growth or test media accommodated within the petri-dish 4 placed on the sampling section 3. For clarification it is noted that in operation of the particle monitoring system the lid of the petri dish 4 is removed. The fluid, after having impinged on the media in the petri-dish 4, is guided towards the periphery of the sieve section 6 and from there through a gap 16 between the support section 2 and the petri-dish 4 to an outlet port 3b of the sampling section (the flow of the fluid is forced by a reduced pressure created by a vacuum pump downstream of the outlet port 3b).

[0045] The support section 2 and the sieve section 6 of the sampling lid 1 are integrally formed, preferably are integrally molded, preferably by injection molding. Thus, the sampling lid 1 is preferably a disposable solution composed of a single-use disposable plastic part compatible with an environmental monitoring air sampler in order to avoid the need for autoclaving. The choice of plastics material is not particularly limited. A suitable plastics material may, for example, be selected from the list consisting of acrylonitrile butadiene styrene (ABS); polypropylene (PP), such as propylene homopolymer, propylene random copolymer, or heterophasic propylene block copolymer; polycarbonate (PC); polystyrene (PS), such as high-impact polystyrene (HIPS); polyamides (PA); and polyesters.

[0046] The form, number and arrangement of the openings 7 on the upper side of the sieve section 6 is not particularly limited as long as it fulfils the function of directing a desired flow of fluid towards the media in the petri-dish 4. In the embodiment the openings 7 are in the form of radially aligned rows of small holes directed towards a center of the sieve section. The surface where the openings are formed is in the form of a recessed, troughlike portion 11 surrounded by an elevated peripheral rim 12. The lower side of the peripheral rim 12 accommodates and forms an annular channel 13 for directing the fluid through a gap 16 between the sampling lid 1 and the petri-dish 4 to the outlet port 3b.

[0047] The sieve section 6 is peripherally surrounded by the raised peripheral rim 12 of the support section 2 and preferably is axially recessed from a top surface 12a of the peripheral rim 12 of the support section 2 towards the impacting and collecting surface, preferably the petri dish 4 to form the trough-like portion 11. Further, as shown in Figure lc, the peripheral rim 12 of the support section 2, on a side facing the sampling section 3 of the particle monitoring system, is formed so as to surround, in the mounted state on the sampling section 3, a raised outer peripheral wall 4a of the impacting and collecting surface, preferably the petri dish 4, creating an inverted U- or V-shaped gap 16 through which a fluid can pass from a central region 5a of the space 5 above the impacting and collecting surface and below the sieve section 6 to an outer peripheral region 5b of the space 5 surrounding the impacting and collecting surface, preferably the petri dish 4. As shown in Figures la and lb, the support section 2 is provided with a plurality of radial ribs and / or recesses 9 between the ribs (or, not shown, recessed in a smooth outer wall surface) distributed about the outer periphery thereof in equal intervals to allow or at least facilitate gripping of the support section 2 by a gripper implement 17 of a robot for the purpose of positioning it on the sampling section 3 and / or to increase the rigidity against deformation (see also Figures 2d and 2e).

[0048] Although not shown, the elevated peripheral rim 12 surrounding the sieve section 6 may also be provided with a number of radial ribs on its upper side, distributed about the circumference, to enhance, in addition to the effect of the elevated peripheral rim 12 and the radial ribs or protrusions 9, the rigidity of the sampling lid 1 against bending deformation while allowing the material thickness of the walls as such to be reduced. This allows that the sampling lid 1 can be gripped and handled by a gripper implement 17 of a robot (see Figures 2d and 2e) or by a hand of a user.

[0049] The support section 2 may be specifically designed to have a relatively simple geometrical shape with mainly flat and preferably uninterrupted continuous smooth surfaces (except for the above-mentioned ribs 9) and only a minimum of recesses or sharp edges. Thus, it can be easily formed by injection molding.

[0050] In the embodiment the support section 2 is a ring-like body that comprises a lower skirt portion 2a and an upper skirt portion 2b, the lower skirt portion 2a having a slightly larger diameter than the upper skirt portion 2b such that there is a step-like transition portion 2c between the two. The stepped structure enhances the rigidity of the sampling lid against distortion, in particular when the lid is handled by the gripper implement, yet allows for a reduction of the material thickness.

[0051] In the embodiment the outer ribs or protrusions 9 are formed as extensions of the lower skirt portion 2a extending onto the upper skirt portion 2b beyond the step-like transition portion 2c. Further, the lower skirt portion 2a is formed to surround and preferably releasably engage with a peripheral edge 3c of the sampling section 3 to create a sealing contact. The sealing contact may, however, be also formed by flat mating surfaces that are pressed against each other upon application of the vacuum described later.

[0052] The lateral ribs or protrusions 9 and / or recesses help avoiding that the sampling lid slides through the gripper implement 17 of a robot or gloves in case of manual handling. For ease of implementation, the support section 2 preferably has a sufficiently wide essentially vertical surface along the outer perimeter, to allow easy and reliable gripping.

[0053] The support section 2 is designed to be fixed to the base 3a of the sampling section 3. This can be realized in that the support section 2 and the base 3a are provided with mating centering and engaging features for defining a releasable mounted position. The releasable connection between the base 3a and the support section 2 should be more rigid if the sampling lid 1 is to remain in place for several sampling cycles.

[0054] The disposable sampling lid 1 may be configured to be engaged with other sampling lids of the same configuration to form a self-supporting stack.

[0055] Following its production the present sampling lid 1 can, due to its simple integral design, be easily subjected to one or more cleaning or sterilization steps, for which any of the known sterilization methods, such as sterilization by gamma rays, steam or ozone, to only name a few, may be used, thus brining the sampling lid 1 to a desired and manufacturer- guaranteed level of sterility (or cleanness). The possibility of being able to obtain already pre-sterilized sampling lids 1 is advantageous for a wide range of different users. For example, users not having any sterilization capabilities, for example, because they do not have a sufficient number of regular tests to perform in a given time or only sporadically need to perform such tests, may keep a stock of pre-sterilized sampling lids 1 at hand, ready for use at any given time, thus also allowing for tests to be performed on short notice. And, for example, users performing a high number of tests in a given period of time take assurance from the guaranteed consistent sterility level from one sampling lid to the next, thus essentially avoiding the risk of getting false positive results, having the consequence that potentially, for example, in the manufacturing of medicines complete production runs or batches are unnecessarily discarded, leading to an avoidable financial loss.

[0056] Further, the sampling lid 1 can be provided with a relatively simple rigid primary packaging for the single use in order to permit the automation and robotic use. There will be a synergy of functions between the packaging and the single use sampling lid for robotic and automated use. The rigid packaging will permit to keep the sampling lid sterile until the last moment before its use.

[0057] Figures 2a to 2e show a sequence of characteristic steps of an air monitoring process using the sampling lid 1 according to the embodiment in a perspective view (Figures 2a, 2c, 2d, 2e) and in a perspective cross-sectional view (Figure 2b), each in conjunction with the sampling section 3 of a particle monitoring system.

[0058] To start an air monitoring process, the petri-dish 4 (with the growth or test media, for example agar media) is placed on the base 3a of the sampling section 3 of the particle monitoring system (for example an air sampling system). This step is shown in Figures 2a and 2b and is as such known in the art. The petri-dish 4 can be positioned indifferently manually or automatically with a robot.

[0059] Then, the disposable sampling lid 1 is positioned on the base 3a of the sampling section 3, too, so as to surround the petri-dish 4 with a gap 16 (see Figures lb and lc). The sampling lid 1 can be positioned indifferently manually (Figure 2c) or automatically with a robot (Figure 2d), wherein Figure 2d indicates an example where the sampling lid 1 is gripped by a gripper implement 17 of such a handling robot (not shown). The rigidity of the disposable sampling lid 1 and, if necessary, the use of a rigid packaging (not shown) as primary packaging of the disposable sampling lid 1 will permit the automation and robotic use of the proposed solution by using the gripper implement 17. The primary packaging can be a single unit packaging or a packaging of several sampling lids 1. In the second case, the design of the sampling lids lwill preferably allow them to be easily stacked and taken up one-by-one by the gripper implement 17.

[0060] Once the sampling lid 1 is placed on top of the base 3a of the sampling section 3 (see Figure 2e), the fluid sampling system is ready to start and a vacuum pump (not shown) is started to suck fluid (air) through the holes 7 of the sieve section 6 via the port 3b of the air sampling system and the contaminated particles entrained in the stream of fluid are projected onto the surface of the media within the petri-dish 4 by the kinetic energy and remain on the media surface. The sucked fluid is forced radially outward and upward at the peripheral wall 4a of the petri-dish 4 through the gap 16 between the raised peripheral rim 12 and the wall 4a and is further guided and turned downward by the annular channel 13 between the sampling lid 1 and the petri-dish 4 and is directed to the outlet port 3b to finally exit through the port 3b of the air sampling system (see also Figure lc).

[0061] Thus, a gas (preferably, an air) monitoring process as described herein comprises the steps of

[0062] (a) providing a petri dish (4) comprising a lid and a bottom;

[0063] (b) placing the petri dish (4) onto a base (3a) of a particle monitoring system, and removing the lid of the petri dish (4); (c) positioning a disposable sampling lid (1) as defined in any one of claims 1 to 12 onto the base (3a), the disposable sampling lid (1) comprising fluid openings (7) of a sieve section (6); and

[0064] (d) sucking fluid (e.g. a gas or air) through the fluid openings (7) of the sieve section (6), thereby collecting particles entrained in the stream of fluid on the surface of the petri dish (4).

[0065] Step (d) is generally continued for a pre-defined time, upon which the lid put onto the petri dish 4 again, and the petri dish 4 removed from the base 3a.

[0066] Step (c) of the gas monitoring process may be performed manually or by using a robot.

[0067] In a preferred variant (not shown) the sieve section 6 and / or the support section 2 and optionally the air sampling system are / is provided with a data tag containing an identifier, preferably of an electronically readable type that is attached on an accessible outer surface of the respective components (for example on an outer peripheral surface of the lower skirt portion 2a), that can have a unique data matrix for ensuring an unambiguous traceability of the test performed. Such traceability reading should be compatible for both manual and automated use.

[0068] In the embodiment the inner diameter of the ring-like support section can be dimensioned to tightly fit about an outer circumference of the base 3a of the sampling section 3 so that the support section 2 of the sampling lid 1 is configured to be moved along a body of the base 3a of the sampling section 3 between a raised position where it facilitates unimpeded loading of the petri-dish 4 and a lowered position where the substantially closed space 5 surrounding the petri-dish 4 placed on the sampling section 3 is defined by the sampling lid 1.

Claims

Claims1. A sampling lid (1) for a particle monitoring system comprising:(i) a support section (2) configured to be releasably attached to a sampling section (3) of the particle monitoring system and to define a space (5) surrounding an impacting and collecting surface, preferably a petri dish (4), placed on the sampling section (3); and(ii) a sieve section (6) supported by the support section (2) to close an open side of the space (5) above the impacting and collecting surface, preferably the petri-dish (4), the sieve section (6) provided with fluid openings (7) arranged to direct, in operation of the particle monitoring system, a fluid towards the impacting and collecting surface, preferably the petri dish (4), placed on the sampling section (3).

2. The sampling lid (1) according to claim 1, wherein the support section (2) and the sieve section (6) are integrally formed, preferably are integrally molded, preferably by injection molding.

3. The sampling lid (1) according to claim 1 or 2, wherein the support section (2) is configured to be moved along a body of the sampling section (3) of the particle monitoring system between a position where it defines the space (5) surrounding the impacting and collecting surface, preferably the petri dish (4), placed on the sampling section (3) and a position providing access to the sampling section (3).

4. The sampling lid (1) according to any one of claims 1 to 3, wherein the support section (2) is provided with a plurality of radial ribs or protrusions (9) and / or recesses distributed about the periphery thereof to allow gripping of the support section (2) by a gripper implement (17) of a robot for the purpose of positioning it on the sampling section (3) and / or to increase the rigidity against deformation.

5. The sampling lid (1) according to any one of claims 1 to 4, wherein the support section (2) comprises a lower skirt portion (2a) and an upper skirt portion (2b), the lower skirt portion (2a) having a larger diameter than the upper skirt portion (2b) such that there is a step-like transition portion (2c) between the two.

6. The sampling lid (1) according to claim 5 in combination with claim 4, wherein the ribs (9) are formed as extensions of the lower skirt portion (2a) extending onto the upper skirt portion (2b) beyond the step-like transition portion (2c).

7. The sampling lid (1) according to claim 5 or claim 6, wherein the lower skirt portion (2a) is formed to surround and releasably engage with a peripheral edge (3c) of the sampling section (3).

8. The sampling lid (1) according to any one of claims 1 to 7, wherein the support section (2) is a ring-like body.

9. The sampling lid (1) according to any one of claims 1 to 8, wherein the sieve section (6) is peripherally surrounded by a peripheral rim (12) of the support section (2) and preferably is axially recessed from a top surface (12a) of the peripheral rim (12) of the support section (2) towards the impacting and collecting surface, preferably the petri dish (4) to form a trough-like portion (11).

10. The sampling lid (1) according to claim 9, wherein the peripheral rim (12) of the support section (2), on a side facing the sampling section (3) of the particle monitoring system, is formed so as to surround, in the mounted state on the sampling section (3), a raised outer peripheral wall (4a) of the impacting and collecting surface, preferably the petri dish (4), creating an inverted U- or V-shaped gap (16) through which a fluid can pass from a central region (5a) of the space (5) above the impacting and collecting surface and below the sieve section (6) to an outer peripheral region (5b) of the space (5) surrounding the impacting and collecting surface, preferably the petri dish (4).

11. The sampling lid (1) according to any one of claims 1 to 10, wherein the sampling lid (1) is configured to be engaged with other sampling lids (1) of the same configuration to form a self-supporting stack.

12. The sampling lid (1) according to any one of claims 1 to 11, wherein the sieve section (6) and / or the support section (2) are / is provided with a data tag containing an identifier, preferably of an electronically readable type.

13. The sampling lid (1) according to any one of claims 1 to 12, wherein the sampling lid (1) comprises an impacting and collecting surface, preferably a petri dish (4).

14. A particle monitoring system comprising the sampling lid of any one of claims 1 to 13.

15. A gas monitoring process comprising the steps of(a) providing a petri dish (4) comprising a lid and a bottom;(b) placing the petri dish (4) onto a base (3a) of a particle monitoring system, and removing the lid of the petri dish (4);(c) positioning a disposable sampling lid (1) as defined in any one of claims 1 to 12 onto the base (3a), the disposable sampling lid (1) comprising fluid openings (7) of a sieve section (6); and(d) sucking fluid (e.g. a gas or air) through the fluid openings (7) of the sieve section (6), thereby collecting particles entrained in the stream of fluid on the surface of the petri dish (4).

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