Nutrient dish holder

Abstract

The present invention relates to a device (1), particularly for microbial air sampling (1), comprising: a base (3) comprising a top side (30a) configured for supporting a dish (2) when the dish (2) is placed on said top side (30a), and a plurality of holding elements (4) protruding from the top side (30a) and configured to hold the dish (2) to delimit a movement of the dish (2) along the top side (30a) of the base (3) when the dish (2) is placed on the top side (30a) between the holding elements (4), wherein a position of the at least one holding element (4) on the top side (30a) of the base (3) is adjustable to account for different outer diameters (D) of the dish (2) to be held by the holding elements (4).

Description

[0001] mbv112ep 1

[0002] Nutrient dish holder

[0003] The present invention relates to a device comprising a dish holder, particularly to an analytical device such as a microbial air sampler.

[0004] The present invention can be particularly applied in the field of particle collection and sampling as well as analysis of particles of all kinds and more, particularly any setup holding a nutrient dish or another dish in a similar shape. Especially, it is related to devices for characterization of gas or air quality as necessary in food and beverage industries or clean environments such as cleanrooms and manufacturing environments. Examples for such clean environments are production lines in the pharmaceutical industries, where air quality must be constantly observed and tested.

[0005] Microbial air samplers are a specific type of air monitoring devices that focus on the collection of particles on a microbial growth medium - usually in form of a nutrient dish filled with agar media or similar. The dish is placed under a lid with a perforated sieve, essential for the collection of particles to take place. After collection of particles from the gas / air on such a medium plate, the plate is incubated for several hours or even days to let collected living microorganisms grow into visible colonies for subsequent counting and analysis.

[0006] However, the placement of the agar / nutrient media dishes is a critical design part of a device, particularly an analytical device such as an air sampler.

[0007] In the state of the art, brackets are known for holding a dish that are held in place by screws and are pressed outwards by a spring, respectively. In such designs, the brackets can tilt outwards, when holding a dish. Such a tilting movement leads to a compression of the lower part of the spring, resulting in a force holding the dish. Tightening / loosening of the respective screw allows adjusting the position of the bracket in a limited range to the diameter of the dish.

[0008] Furthermore, brackets for holding a dish are known in the prior art that can be adjusted radially through rotation of a central table on which the dish rests.

[0009] Further, brackets made from metal sheets and fixed in place with screws are known in the state of the art, wherein these brackets are adjustable by moving the respective bracket along the respective screw. The brackets are elastically deformable to exert a holding force on the dish, a central table is not needed as a support for the dish.

[0010] Furthermore, fixed pins are known in the state of the art that are configured for centering a dish, but not for clamping it. mbv112ep 2

[0011] Furthermore, fixed brackets are known (e.g. made from plastic or sheet metal), one of which comprises a lever for pressing the petri dish against the other brackets.

[0012] Furthermore, recesses formed in a table that serves for supporting the dish are known, which recesses allow to center the nutrient dish.

[0013] Further, a removable flat table (without feet) for supporting a dish is known in the state of the art, which table is held in place magnetically and allows removing of the table to permit autoclaving and ultrasonic cleaning of the table, wherein the table includes integrated brackets for clamping the dish radially.

[0014] Known holding systems for nutrient dishes often contain screws and / or visible / exposed cylindrical springs which are hard to clean and are time-consuming regarding assembly.

[0015] Furthermore, known holding systems typically only cover a limited range of dish diameters. Often, an adjustment of the brackets is only possible within small ranges. Frequently, accessories (which may be difficult to clean or handle) or conversion sets are required to adjust the holding system to different dish diameters.

[0016] Furthermore, cleaning underneath the dish supporting table is often limited or not possible in case of non-removable tables.

[0017] Based on the above, the problem to be solved by the present invention is to provide a device comprising a dish holder that is improved regarding at least one of the above-mentioned difficulties.

[0018] The above-stated problem underlying the present invention is solved by a device having the features of claim 1.

[0019] Preferred embodiments of these aspects of the present invention are stated in the corresponding dependent claims and are also described below.

[0020] According to claim 1 , a device, particularly for microbial air sampling, is disclosed, the device comprising:

[0021] - a base comprising a top side configured for supporting a dish (containing e.g. a nutrient medium) when the dish is placed on said top side, and

[0022] - a plurality of holding elements protruding from the top side and configured to hold the dish to delimit an e.g. horizontal movement of the dish along the top side of the base when the dish is placed on the top side between the holding elements, wherein particularly the holding elements are arranged radially offset from a center of the top side of the base, mbv112ep 3 wherein a position of the at least one holding element on the top side of the base is adjustable to account for different outer diameters of the dish to be held by the holding elements.

[0023] In a preferred embodiment a position of each holding element of said plurality of holding elements is adjustable on the top side of the base to account for different outer diameters of the dish to be held by the holding elements. Preferably, the device comprises three holding elements, wherein particularly said plurality of holding elements consists of exactly three holding elements.

[0024] Preferably, the at least one holding element is individually adjustable independently from the other holding elements. Preferably, each holding element is individually adjustable independently from each of the other holding elements.

[0025] In a preferred embodiment, the at least one holding element is supported on a supporting element, the supporting element being configured to be adjusted by rotating it about a rotation axis of the supporting element with respect to the base to let the supporting element assume an angular position of a plurality of different angular positions with respect to the rotation axis to adjust said position of the at least one holding element on the top side of the base, wherein the at least one holding element protrudes from the supporting element laterally offset from the rotation axis. Particularly, said plurality of different angular positions may correspond to a discrete set of angular positions or to a continuous range of different angular positions. In other words, in particular, said adjustment of the angular positions can be discrete (i.e. stepwise) or continuous.

[0026] Particularly, the at least one holding element is eccentric and consequently, when the corresponding supporting element is adjusted / rotated about the rotation axis, the position of the holding element along the top side changes due to the at least one holding element being eccentric, i.e., arranged laterally offset from the rotation axis. Particularly, a longitudinal axis of the at least one holding element extends parallel to the rotation axis.

[0027] Furthermore, in a preferred embodiment of the present invention, each holding element is supported on a supporting element, the respective supporting element being configured to be adjusted (e.g. stepwise or continuously, see also above) by rotating it about a rotation axis of the respective supporting element with respect to the base to let the respective supporting element assume an angular position of a plurality of different angular positions with respect to the rotation axis of the respective supporting element to adjust said position of the respective holding element on the top side of the base, wherein preferably the respective holding element protrudes from the respective supporting element laterally offset from the rotation axis of the respective supporting element. Particularly, a longitudinal axis of the mbv112ep 4 respective holding element extends parallel to the rotation axis of the respective supporting element.

[0028] According to yet another preferred embodiment, the supporting element of the at least one holding element is configured to be arranged in an opening (preferably in a form-fitting manner) formed in the top side of the base. According to a further preferred embodiment, each supporting element can be configured to be arranged in an opening (preferably in a form fitting manner) formed in the top side of the base.

[0029] Furthermore, in a preferred embodiment of the present invention, the supporting element of the at least one holding element is configured to be rotated about said rotation axis (particularly while being arranged in said opening) in an unarrested state to assume one of said plurality of different angular positions and configured to be non-rotatable about the rotation axis in an arrested state. According to yet another preferred embodiment of the present invention, each supporting element is configured to be rotated about a rotation axis of the respective supporting element (particularly while being arranged in said opening associated to the respective supporting element) in an unarrested state of the respective supporting element to assume one of said plurality of different angular positions of the respective supporting element and configured to be non-rotatable about the rotation axis in an arrested state of the respective supporting element.

[0030] Furthermore, according to yet another preferred embodiment, the device, particularly the base, comprises an arresting device for the supporting element of the at least one holding element, the arresting device being configured to allow rotation of the supporting element in the unarrested state and configured to arrest the supporting element to prevent rotation of the supporting element in the arrested state. According to yet another preferred embodiment, the device, particularly the base, comprises an arresting device for each supporting element, the respective arresting device being configured to allow rotation of the respective supporting element in the unarrested state and configured to arrest the respective supporting element to prevent rotation of the respective supporting element in the arrested state.

[0031] According to a further preferred embodiment of the present invention, the arresting device for the supporting element of the at least one holding element comprises a plurality of stops, wherein the supporting element is configured to engage in each of said different angular positions of the supporting element between two neighboring stops of said plurality of stops comprised by the arresting device to assume the arrested state, and wherein the supporting element is configured to disengage with the two neighboring stops when (e.g. manually) lifting the supporting element in a lifting direction (e.g. by means the holding element used as a handle), wherein particularly the lifting direction extends parallel to the rotation axis. Particularly, in a preferred embodiment, each arresting device comprises a plurality of stops, mbv112ep 5 wherein the respective supporting element is configured to engage in each of said different angular positions of the respective supporting element with two neighboring stops of said plurality of stops comprised by the respective arresting device to assume the arrested state of the respective supporting element, and wherein the respective supporting element is configured to disengage with the two neighboring stops when (e.g. manually) lifting the respective supporting element in a lifting direction, wherein particularly the respective lifting direction extends parallel to the rotation axis of the respective supporting element.

[0032] Furthermore, according to a preferred embodiment, when the supporting element of the at least one holding element is in the arrested state, a top side of the supporting element is flush with a surrounding portion of the top side of the base, wherein in the unarrested state the supporting element protrudes out of the opening on the top side due to being lifted in the lifting direction and is preferably rotatable in the opening to adjust the angular position of the supporting element. Furthermore, in a preferred embodiment of the invention, this applies to each supporting element, i.e. , when the respective supporting element is in the arrested state, a top side of the respective supporting element is flush with a surrounding portion of the top side of the base, wherein in the unarrested state the respective supporting element protrudes out of the corresponding opening on the top side due to being lifted in the lifting direction and is preferably rotatable in the respective opening to adjust the angular position of the respective supporting element.

[0033] Furthermore, according to a further preferred embodiment of the present invention, the holding elements are configured to clamp the dish when the dish is arranged on said top surface of the base between the holding elements.

[0034] Further, according to yet another preferred embodiment of the present invention, the supporting element of the at least one holding element comprises a spring element to allow tensioning of the at least one holding element against the dish held between the holding elements in the arrested state of the supporting element. Further, according to a preferred embodiment, this applies to each supporting element, i.e., the respective supporting element comprises a spring element to allow tensioning of the corresponding holding element against the dish held between the holding elements in the arrested state of the supporting elements.

[0035] In a preferred embodiment, the spring element of the supporting element of the at least one holding element is a coil spring. Furthermore, in a preferred embodiment, this applies to the spring element of each supporting element.

[0036] According to a preferred embodiment of the present invention, the spring element of the supporting element of the at least one holding element comprises an end portion configured to engage between the two neighboring stops of said plurality of stops comprised by the arresting device associated with the supporting element of the at least one holding element, mbv112ep 6 to let the supporting element of the at least one holding element assume the arrested state. Furthermore, in a preferred embodiment, this also applies to the spring element of each supporting element, i.e., the spring element of the respective supporting element comprises an end portion configured to engage between two neighboring stops of said plurality of stops comprised by the arresting device associated with the respective supporting element, to let the respective supporting element assume the arrested state.

[0037] In a further preferred embodiment of the invention, the base comprises a receptacle accommodating the supporting element of the at least one holding element, wherein said plurality of stops comprised by the arresting device associated with the supporting element of the at least one holding element is arranged in the receptacle accommodating the supporting element of the at least one holding element, wherein particularly the respective stop of said plurality of stops is arranged on a bottom and / or an inner side of this receptacle, wherein particularly the supporting element of the at least one holding element is configured to move partially out of the receptacle through said opening (e.g. when being lifted in the lifting direction) in which the supporting element of the at least one holding element is arranged. Furthermore, in a preferred embodiment, these features apply to each supporting element, i.e., the base comprises a receptacle accommodating the respective supporting element, wherein said plurality of stops comprised by the arresting device associated with the respective supporting element is arranged in the receptacle accommodating the respective supporting element, wherein particularly the respective stop of said plurality of stops is arranged on a bottom and / or an inner side of the receptacle accommodating the respective supporting element, wherein particularly the respective supporting element is configured to move partially out of its receptacle through the opening (e.g. when being lifted in the lifting direction) in which the respective supporting element is arranged.

[0038] According to yet another preferred embodiment of the present invention, the base and the supporting element of the at least one holding element are configured to attract each other by a magnetic force, particularly so as to prevent the supporting element of the at least one holding element from accidentally moving out of its arrested state into the unarrested state, e.g. when the device is not standing upright but is being handled or moved or when removing the dish is creating a vertical (e.g. friction) force onto the at least one holding element which creates a vertical force on the supporting element of the at least one holding element. Furthermore, in a preferred embodiment of the invention, this applies to the base and each supporting element, i.e., the base and the respective supporting element are configured to attract each other by a magnetic force, particularly so as to prevent the respective supporting element from accidentally moving out of its arrested state into the unarrested state, e.g. in the afore-described situations. mbv112ep 7

[0039] Furthermore, in a preferred embodiment, the supporting element of the at least one holding element comprises an (e.g. circumferential) flange having an outer diameter being larger than an inner diameter of the opening in which the supporting element of the at least one holding element is arranged, particularly to prevent the supporting element of the at least one holding element from being removed from its associated opening in the tops side of the base.

[0040] According to yet another preferred embodiment of the present invention, the top side of the base comprises a circumferential protrusion.

[0041] Further, in a preferred embodiment, the opening in which the supporting element of the at least one holding element is arranged, is arranged in a portion of the circumferential protrusion. Furthermore, according to a preferred embodiment, this also applies to each supporting element, i.e. , the opening in which the respective supporting element is arranged, is arranged in a portion of the circumferential protrusion.

[0042] According to yet another preferred embodiment, the top side of the base forms a recess to allow air to pass underneath the dish, when the dish is being held by the holding elements, wherein said recess is surrounded by the circumferential protrusion.

[0043] Furthermore, in a preferred embodiment, a central opening is arranged in said recess for extracting said air.

[0044] According to yet a further preferred embodiment of the invention, the device is a microbial air sampler, wherein particularly the respective dish to be held by the holding elements contains a nutrient medium.

[0045] Particularly, the device (e.g. microbial air sampler) can comprise a lid that is configured to be arranged on the top side of the base to enclose a dish being held by the holding elements in an interior space of the device formed by the lid and the top side of the base when the lid is arranged on the top side of the base.

[0046] In the following, embodiments of the present invention as well further features and advantages and other aspects of the present invention shall be described with reference to the Figures, wherein

[0047] Fig. 1A shows a perspective view onto a top side of a base of an embodiment of a device according to the present invention;

[0048] Fig. 1 B-G show different views onto dishes held on the top side of a base of the device of Fig. 1A according to the present invention illustrating the adaptability of the device to dishes of different outer diameter, e.g. an outer diameter of 90 mm (B and C), 55 mm (D and E), 82 mm (F and G);

[0049] Fig. 2 shows an exploded view of the base of the device of Fig. 1 A; mbv112ep 8

[0050] Fig. 3 shows a further exploded view of the base of the device of Fig. 1 A;

[0051] Fig. 4 shows a cross-sectional view of an embodiment of a supporting element of a holding element of a device according to the present invention;

[0052] Fig. 5 shows a perspective top view onto a receptacle for accommodating the supporting element shown in Fig. 4 also indicating a spring element of the supporting element (with a portion of the supporting element being removed to reveal an interaction between the spring element and a plurality of stops arranged in the receptacle);

[0053] Figs. 6-7 show different views of the supporting element of Figs. 4-5 with the supporting element being depicted partially as transparent to show the position of its spring element;

[0054] Fig. 8 shows a perspective view of an embodiment of the device according to the present invention in form of a microbial air sampler, wherein the top side of the base can be covered with a lid covering the supporting elements and holding elements connected thereto as well as the dish to be held; and

[0055] Fig. 9 shows a schematic cross-sectional view of an embodiment of the device according to the present invention in form of a microbial air sampler.

[0056] Fig. 1A shows in conjunction with Fig. 1B-F an embodiment of a device 1 according to the present invention, particularly for microbial air sampling 1, wherein the device 1 comprises a base 3 comprising a top side 30a configured for supporting a dish 2 when the dish 2 is placed on said top side 30a, and a plurality of holding elements 4 protruding from the top side 30a and configured to hold the dish 2 to delimit an (e.g. horizontal) movement of the dish 2 along the top side 30a of the base 3 when the dish 2 is placed on the top side 30a between the holding elements 4, wherein particularly the holding elements 4 are arranged radially offset from a center of the top side 30a of the base 3. According to the present invention, a position of the at least one holding element 4 on the top side 30a of the base 3 is adjustable to account for different outer diameters D of the dish 31 to be held by the holding elements 4. Preferably, each of the holding elements 4 is adjustable to account for different outer diameters D of dishes 2 to be held by the holding elements 4, wherein the device 1 preferably comprises three holding elements 4, as will be described in the following.

[0057] However, in certain preferred embodiments merely at least one holding element 4 may be adjustable to account for different diameters of dishes 2 to be clamped, or any other suitable number of holding elements 4 may be adjustable to this end. Furthermore, preferably, each of the holding elements 4 is individually adjustable, namely independently from all the other mbv112ep 9 holding elements 4 of the device 1. Figs. 1B-G illustrate the device 1 holding dishes 2 of different diameters between its adjustable holding elements 4.

[0058] Particularly, the respective holding element 4 is supported on a supporting element 40, wherein the respective supporting element 40 is configured to be adjusted by rotating it about a particularly virtual rotation axis z of the respective supporting element 40 with respect to the base 3 as best shown in Fig. 1A in conjunction with Fig. 4. Particularly, the respective holding element 4 is arranged laterally offset from the rotation axis z of the respective supporting element 40 from which the respective holding element 4 protrudes, so that a rotation of the respective supporting element 40 about its rotation axis z changes an angular position of the respective supporting element 40 with respect to the rotation axis z and thereby moves its holding element 4 inwards or outwards on the top side 30a of the base 3 depending on the starting position and rotation direction of the considered holding element 4 as the holding elements 4 are eccentrically arranged on the respective supporting element 40 (cf. Figs. 1A-F). Particularly, a longitudinal axis of the respective holding element 4 extends parallel to the rotation axis z of its associated supporting element 40.

[0059] As shown in Fig. 4 in conjunction with Figs. 2 to 3, and 5 to 7, the respective supporting element 40 is arranged in an opening 32 (preferably in a form-fitting manner), formed in the top side 30a of the base 3 and can interact with an associated arresting device 5 that is configured to arrest the supporting element 40, so that the latter assumes an arrested state in which it cannot be rotated about its rotation axis z, and to release the supporting element 40, so that it assumes an unarrested state in which the supporting element 40 can be adjusted regarding its angular position to move the associated holding element 4 inwards or outwards as described above.

[0060] Particularly, for arresting the respective supporting element 40, the corresponding arresting device 5 comprises a plurality of stops 50, wherein the supporting element 40 is configured to engage in each of said different angular positions that it can assume between two neighboring stops 50 of said plurality of stops 50 comprised by the arresting device 5 to assume the arrested state, and wherein the supporting element 40 is configured to disengage with the two neighboring stops 50 by lifting the supporting element 40 in a lifting direction L (cf. Fig. 4) that runs parallel to the rotation axis z out of engagement.

[0061] Particularly, as can seen from Fig. 4 and 5, the respective supporting element 40 can comprise a spring element 41, particularly in form of a coil spring, that is fixed to a body 44 of the supporting element 40, which body 44 comprises a top side 40a from which the holding element 4 protrudes (cf. also Figs. 6 and 7), wherein the spring element comprises an end portion 41a by means of which the supporting element 40 engages between the respective two neighboring stops 50 to arrest the supporting element 40. In this arrested state, the top mbv112ep 10 side 40a of the supporting element 401 body 44 is flush with a surrounding portion of the top side 30a of the base as shown in Fig. 4. Particularly, the top side 40a of the respective supporting element 40 forms a portion of the overall top side 30a of the base 3. As the end portion 41a of the spring 41 is engaged with the neighboring stops 50 (cf. Fig. 5) in the arrested state of the supporting element 40, the spring element 41 can tension the holding element 4 against a dish 2 held between the holding elements 4.

[0062] Lifting now the supporting element 40 in the lifting direction L (with the dish 2 removed beforehand) disengages the end portion 41a of the spring element 41 from the neighboring stops 50 which corresponds to the unarrested state of the supporting element 40 in which the latter protrudes partially out of the opening 32 and can be adjusted / rotated about its rotation axis z. Letting the supporting element 40 move downwards again arrests it in its new angular position by having the end portion 41a of the spring element 41 engage between two neighboring stops 50 at the new angular position.

[0063] As further shown in Fig. 4, the base 3 can accommodate each supporting element 40 in a corresponding receptacle 33, wherein the respective supporting element 40 can partially move out of the associated receptacle 33 (e.g. for the purpose of adjusting the angular position of the respective supporting element 40) through the corresponding opening 32 formed in the top side 30a of the base 3. Particularly, said plurality of stops 50 can be arranged in the receptacle 33, wherein particularly the respective stop 50 of said plurality of stops is can formed on a bottom side 33b and / or an inner side 33a of the receptacle 33.

[0064] In order to prevent that the respective supporting element 40 accidentally moves from the arrested state into its unarrested state, e.g. when the device 1 is not standing upright (as e.g. shown in Fig. 8) but is being handled or moved, or when removing a dish 2 held by the holding elements 4 is creating a vertical (friction) force onto the holding elements 4 which creates a vertical force on the supporting elements 40, each supporting element 40 can be attracted by a permanent magnet 42 arranged e.g. at the bottom 33b of the respective receptacle 33 (cf. Fig. 4), wherein particularly the respective magnet 42 can attract a ferromagnetic screw 43 (cf. also Fig. 7) that fixes the spring element 41 to the body 44 of the respective supporting element 40. In order to prevent the respective supporting element 40 from moving out of the respective opening 32 / receptacle 33 completely, the respective supporting element 40 can comprise a circumferential flange 40b having an outer diameter being larger than an inner diameter of the respective opening 32 (cf. Figs. 4, 6, and 7).

[0065] Further, as shown e.g. in Fig. 1 A, the top side 30a of the base 3 can comprise a circumferential protrusion 31 having broadened sections 31a in which the openings 32 with the supporting elements 40 therein are arranged so that the dish 2 to be held by the holding elements 4 can rest on the sections 31a allowing air to pass under the dish 2 into a recess mbv112ep 11

[0066] 34 formed into the top side 30a of the base 3 (cf. also Figs. 1 B to 1G). An opening 35 can be arranged in the recess 34 for extracting said air. Particularly the opening 35 can be a central opening 35 arranged in the center of the recess 34. Particularly a transition between a bottom of the recess 34 and the surrounding protrusion 31 is rounded, particularly so as to improve cleanability of the top side 30a of the base 3.

[0067] Preferably, in the individual embodiments described herein, the device 1 is an (e.g. portable) microbial air sampler, wherein the dish 2 to be held by the holding elements 4 serves to carry a nutrient medium 2a for promoting microbial growth. The device 1 is configured to collect particulate matter, particularly microbes, on the medium 2a to have it cultivated after collection.

[0068] Particularly, such a microbial air sampler 1 , as shown in Figs. 8 and 9 can comprise a lid 36 that is configured to be arranged on the top side 30a of the base 3 to enclose the dish 2 (and nutrient medium 2a therein) being held by the holding elements 4 in an interior space 20 of the device 1 formed by the lid 36 and the top side 30a of the base 3 when the lid 36 is arranged on the top side 30a of the base 3.

[0069] The device 1 can draw a fluid flow F (here a gas such as air) through openings 36a provided in the lid 36 of the device 1 and via the opening 35 provided in the top side 30a of the base 3 along a flow channel 10. To this end, the device 1 can comprise an integrated fluid flow generating device 7 (such as a blower comprising a motor 7a and an impeller 7b) that moves the fluid flow F through the flow channel 10 forming a sensing path, wherein the fluid flow F is eventually released via an outlet 17 that can be formed in the base 3. Particularly, a replaceable filter 12 can be placed upstream said outlet 17.

[0070] The dish 2 can be positioned such that the flow channel 10 extends along the nutrient medium 2a residing in the dish 2. The fluid flow generating device 7 is configured to let the fluid flow F pass through the flow channel 10 so that the fluid flow F passes the medium 2a carried by the dish 2 such that particulate matter contained in said fluid flow F settles on the medium 2a. Furthermore, the device 1 can control the fluid flow F so that collecting the particulate matter is conducted in a reproducible fashion. To this end, the flow channel / sensing path 10 can comprises a thermal flow sensor 8 measuring the pressure drop along a specific portion of the flow channel 10 (this section may include elements such as a constriction 11 , a venturi configuration, an orifice, or similar) or between a specific point in the flow channel 10 and the ambient environment Pambient, and sensors for the parameters: temperature T, absolute pressure P and relative humidity RH. The latter parameters may be measured by a single sensor device having integrated therein the functionalities to measure said parameters. Particularly, the sensor(s) for P, T, RH allow determination of the current air density. The mass flow sensor(s) 8 determine the actual mass flow in the device 1. Requested volume flow (i.e., mbv112ep 12 the volume flow set point) and the actual fluid (e.g., air) density can be used to calculate the volume flow equivalent mass flow set point. The fluid flow generating device (e.g. blower) 7 is then controlled such that the mass flow sensor signal matches the desired mass flow set point. Furthermore, the device 1 can comprise a display 18 for displaying e.g. device-related information.

[0071] The present invention provides an advantageous solution for holding a dish 2 by means of adjustable holding elements 4 covering a wide range of nutrient dishes 2 with a simple and effective mechanism comprising a low height of assembly (adding minimally to total height of instrument) and having no exposed springs, screws or screw holes on the top side 30a of the base 3 thus improving cleanability of the device 1. The mechanism can further allow clamping of a dish 2 to hold it in place e.g. when the dish 2 is held in a vertical position to sample horizontal air flows or to prevent shifting of the dish 2 during transport of the device or placing the device at a measurement location (which might well be on a tripod several meters above ground). The device further allows optimal handling for the operator to allow easy loading and unloading of the nutrient dishes 2 and particularly does not contain any sharp edges thus increasing operator safety.

Claims

mbv112ep 13Claims1. A device (1), particularly for microbial air sampling (1), the device (1) comprising:- a base (3) comprising a top side (30a) configured for supporting a dish (2) when the dish (2) is placed on said top side (30a),- a plurality of holding elements (4) protruding from the top side (30a) and configured to hold the dish (2) to delimit a movement of the dish (2) along the top side (30a) of the base (3) when the dish (2) is placed on the top side (30a) between the holding elements (4), wherein a position of the at least one holding element (4) on the top side (30a) of the base (3) is adjustable to account for different outer diameters (D) of the dish (31) to be held by the holding elements (4).

2. The device according to claim 1 , wherein the at least one holding element (4) is supported on a supporting element (40), the supporting element (40) being configured to be adjusted by rotating it about a rotation axis (z) of the supporting element (40) with respect to the base (3) to let the supporting element (40) assume an angular position of a plurality of different angular positions with respect to the rotation axis (z) to adjust said position of the at least one holding element (4) on the top side (30a) of the base (3), wherein the at least one holding element (4) protrudes from the supporting element (40) laterally offset from the rotation axis (z).

3. The device according to claim 2, wherein the supporting element (40) is arranged in an opening (32) formed in the top side (30a) of the base (3).

4. The device according to claim 2 or 3, wherein the supporting element (40) is configured to be rotated about said rotation axis (z) in an unarrested state to assume one of said plurality of different angular positions and configured to be non-rotatable about the rotation axis (z) in an arrested state.

5. The device according to claim 4, wherein the device (1) comprises an arresting device (5) configured to allow rotation of the supporting element (40) in the unarrested state and configured to arrest the supporting element (40) to prevent rotation of the supporting element (40) in the arrested state.mbv112ep 146. The device according to claim 5, wherein the arresting device (5) comprises a plurality of stops (50), wherein the supporting element (40) is configured to engage in each of said different angular positions between two neighboring stops (50) of said plurality of stops comprised by the arresting device (5) to assume the arrested state, and wherein the supporting element (40) is configured to disengage with the two neighboring stops (50) when lifting the supporting element (40) in a lifting direction (L).

7. The device according to one of the preceding claims, wherein the supporting element (40) comprises a spring element (41) to allow tensioning of the at least one holding element (4) against the dish (2) held between the holding elements (4) in the arrested state.

8. The device according to claim 6 or according to claim 7 insofar referring to claim 6, wherein the spring element (41) comprises an end portion (41a) configured to engage between the two neighboring stops (50) to let the supporting element (40) assume the arrested state.

9. The device according to one of the preceding claims, wherein the base (3) comprises a receptacle (33) accommodating the supporting structure (40), wherein particularly said plurality of stops (50) is arranged in the receptacle (33), wherein particularly the respective stop (50) of said plurality of stops is formed on a bottom side (33b) and / or an inner side (33a) of the receptacle (33).

10. The device according to claim 2 or according to one of the claims 3 to 9 insofar referring to claim 2, wherein the base (3) and the supporting element (40) are configured to attract each other by a magnetic force, particularly so as to prevent the supporting element (40) from moving out of its arrested state into the unarrested state.

11. The device according to claim 3 or according to one of the claims 4 to 10 insofar referring to claim 3, wherein the supporting element (40) comprises a flange (40b) having an outer diameter being larger than an inner diameter of the opening (32), particularly to prevent the supporting element (40) from being removed from the opening (32).

12. The device according to one of the preceding claims, wherein the top side (30a) comprises a circumferential protrusion (31).

13. The device according to claims 3 and 12, wherein the opening (32) is arranged in a portion of the circumferential protrusion (31).

14. The device according to claim 12 or 13, wherein the top side (30a) of the base (3) forms a recess (34) to allow air to pass underneath the dish (2), when the dish (2) is beingmbv112ep 15 held by the holding elements (4), wherein said recess (34) is surrounded by the circumferential protrusion (31).

15. The device according to claim 14, wherein a central opening (35) is arranged in said recess (34) for extracting said air.

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