EP3385979A1 - Multipole with a holding device for holding the multipole, holding device of a multipole, mass spectrometer with such a multipole, mounting unit for positioning the multipole and method for positioning a holding device relative to a multipole - Google Patents

Abstract

The invention relates to a multipole (32) with a holding device (10) for holding the multipole (32), for example a quadrupole in a mass spectrometer or on a mounting unit (40), wherein the holding device (10) on the multipole (32) is arranged , For fixing the multipole (32) to a receiving device (36, 36a) for receiving the holding device (10), the holding device (10) has one or more flat bearing surfaces (13, 15). In this case, the holding device (10) is arranged on surfaces (30) of the multipole (32), which are produced together in one working step with electrodes (26A, 26B) of the multipole. The invention further relates to a holding device (10) of such a multipole (32), a mass spectrometer with such a multipole (32), a mounting unit (40) with a receiving device (36, 36a) for positioning a holding device (10) relative to such a multipole (32) and a method for positioning a holding device (10) relative to the multipole (32).

Description

The invention relates to a multipole, in particular a quadrupole, according to the preamble of claim 1. The invention further relates to a holding device of such a multipole, a mass spectrometer with such a multipole, a mounting unit with a receiving device for positioning a holding device on such a multipole and a method for positioning a holding device with respect to the multipole.

In the field of mass spectrometry, multi-pole electrode devices, also called multipoles, have already been known from the prior art for several decades, for example from the German patent specification DE 944900 , The electrode device shown there is used in a mass spectrometer as an analyzer for the separation or the separate detection of ions according to their mass-to-charge ratio. For this purpose, a mass spectrometer essentially comprises three components: an ion source, an analyzer serving as a mass filter, and a detector. In the case of such multipole mass filters, as known for example from the above patent, the separation process works without a magnetic field.

In a quadrupole mass spectrometer, such a multipole or analyzer is designed as a quadrupole. Such a quadrupole comprises four rod electrodes, for example four metal rods, which are arranged parallel to one another, the points of intersection of their longitudinal axes forming a square with a plane running perpendicular thereto. Each diagonally opposite electrodes are held at the same potential, which is composed of a DC voltage component and an AC component. Each pair of diagonally opposite electrodes is thus supplied with a DC and high frequency voltage, wherein the two high frequency voltages are 180 ° out of phase. The ions to be separated are passed as a fine ion beam in the longitudinal direction of the electrodes in the field of the quadrupole.

The applied AC and DC voltage causes a movement of the ions on defined trajectories through the quadrupole, where outside of stable boundary conditions to a collision of the ions with the electrodes, so that the ions are neutralized and therefore no longer reach the detector. In this case, edge regions of the electrodes can represent unstable zones for ions and thus contribute to defocusing. Such is already known from the prior art.

Out DE 10 2013 111 254 A1 For example, an electrode device is known which ensures a precise alignment of the electrodes relative to one another and thus leads to a high analytical measurement accuracy. Furthermore, the invention provides an electrode device with pre- and / or post-filter, which before or are arranged after a main mass filter. These pre- and post-filters are used for introducing and discharging the ion beam and thus the focusing or focusing of the ion beam, whereby an increased transmission rate of the ions and consequently a higher resolution of the mass spectrometer can be achieved. The various sections of the electrodes acting as mass filters serve as ion-optical lenses and the entire electrode device thus constitutes an ion-optical element, in particular in a mass spectrometer.

The precise alignment of the electrodes relative to each other is essential for the analytical accuracy of measurement and takes place here by the attachment of the electrodes to at least one carrier element. The carrier elements are combined with high position accuracy to form an electrode device in order to achieve a high analytical accuracy of measurement of a mass spectrometer. When installed in a mass spectrometer, the electrode device is fixed by means of the carrier elements in the mass spectrometer. For this purpose, the support elements are, for example, annularly arranged in a front and a rear region around the electrodes or at the end faces of the multipole, a ring of insulating material is arranged around the support elements. The electrode device thus has rotationally symmetrical bearing surfaces, with which this electrode device rests in a mass spectrometer, in particular at a correspondingly corresponding receiving device within the mass spectrometer. However, such rotationally symmetric bearing surfaces do not allow high precision positioning and alignment of the electrode device or multipole, e.g. within a mass spectrometer.

It is an object of the present invention to provide a multipole with a holding device which permits exact positioning of the multipole and simplified installation and removal of the multipole, e.g. in a mass spectrometer. Furthermore, the invention has the object to provide a contribution to increasing the measurement accuracy of mass spectrometers.

The invention solves this problem with a multipole with a holding device for holding the multipole with the features of claim 1 and a holding device of a multipole with the features of claim 10. Further, the invention solves this problem with a mass spectrometer with a multipole with the features of claim 11, comprising a mounting unit for positioning a holding device relative to a multipole having the features according to claim 12 and a method for positioning a holding device relative to a multipole with the features according to claim 14.

The invention is based on the finding that conventionally the attachment of an electrode device or a multipole, for example in a mass spectrometer, preferably via an annular, arranged on the support elements of the electrode device holding device, wherein the holding device is formed in two parts and as a respective ring on the end faces of the multipole is arranged and encloses the carrier elements in this case. Such a holding device has two circumferential, rotationally symmetrical bearing surfaces, which at least partially in the attachment of the multipole to a correspondingly corresponding receiving device, in particular in a mass spectrometer issue. However, such rotationally symmetrical bearing surfaces do not allow high-precision positioning and alignment of the electrode device or of the multipole, for example within a mass spectrometer.

According to the invention, therefore, a multipole, for example a quadrupole, is provided with a holding device for holding, for example, for holding the multipole in a mass spectrometer or on a mounting unit, whereby a high-precision alignment and positioning of the multipole is achieved in a particularly simple manner.

The holding device is constructed in one piece or in several parts and arranged on the multipole in order to fix the multipole to a receiving device for receiving the holding device. For this purpose, the holding device has one or more flat bearing surfaces which correspond correspondingly to the receiving device. In this case, the holding device is arranged on surfaces of the multipole, which are manufactured together in one step with electrodes of the multipole. Preferably, these surfaces and the electrodes are ground together with the same grindstone. The surfaces for the arrangement and thus attachment of the holding device on the multi-pole thus have a clear and exact geometric relation to the highly accurately processed electrode surfaces. This ensures that the electrode surfaces, in particular their center can be aligned exactly to the holding device. Thus, the multipole can also be aligned exactly in the mass spectrometer.

Further, the holding device is arranged on the multipole, that the one or more flat bearing surfaces are arranged rotationally asymmetric relative to the central longitudinal axis of the multipole.

Preferably, each flat bearing surface lies in a plane which runs parallel to the central longitudinal axis of the multipole, and is manufactured with high precision. As a result, advantageously, the mounting position of the multipole is precisely defined on the receiving device and determines the multipole in its angular position to the central longitudinal axis of the multipole. This allows a high-precision alignment of the central center longitudinal axis of the multipole to a desired axis of a mounting unit or a mass spectrometer, such as e.g. a connection axis between source, e.g. Ion source or electron source, and detector or to an axis of several successively arranged ion optical or electron optical components, such as ion-optical or electron-optical lenses or filters, and thus a high-precision positioning of the multipole to a desired position in the mass spectrometer or mounting unit.

In addition, the invention allows a simplified installation and removal of the multipole eg in a mass spectrometer, since due to the flat bearing surfaces of the holding device, at least with respect to the angular position of the multipole to the central longitudinal axis of the multipole only two mounting positions of the multipole arise on the receiving device. In the case of maintenance or repair, this leads to a reduced expenditure of time and thus to correspondingly lower costs. In addition, this relief can reduce the risk of damage or misalignment and misalignment of the multipole during maintenance or repair work. Namely, the holding device may, for example, due to its design features described below and their forms of training also serve as a holder or handle for the multipole.

The inventive rotationally asymmetrical design of the bearing surfaces of the holding device determines in contrast to the rotationally symmetrical configuration of the bearing surfaces according to the prior art, the angular position of the multipole relative to the central longitudinal axis of the multipole in the attached state, which advantageously after a mounting and dismounting of the multipole in a mass spectrometer the calibration of the measuring system is simplified and reproducible measurements of the mass spectrometer are generated.

According to one embodiment of the invention, the holding device is arranged laterally of the multipole in the region of a cylinder jacket surface enveloping the multipole. This has the advantage that the flat bearing surfaces machined in the longitudinal direction of the multipole, in particular can be ground with high accuracy.

Advantageously, this processing of the flat bearing surfaces of the holding device is carried out in a grinding process together with the electrodes and mounting surfaces of the support elements of the multipole. This advantageously ensures a highly accurate alignment of the planar bearing surfaces of the holding device with respect to the electrode surfaces.

In a further development of the invention, the holding device is arranged in a central portion of the enveloping cylinder jacket surface, wherein this central portion is arranged symmetrically to the central transverse axis of the multipole and corresponds to a maximum of 90% of the cylinder jacket surface. Advantageously, the holding device is formed in two parts, wherein in each case a part of the holding device is arranged on each side of a cutting plane through the central longitudinal axis of the multipole, in particular centrally or symmetrically to the central transverse axis of the multipole. Such an arrangement of the holding device advantageously ensures a particularly high stability of the attachment of the multipole, in particular in the case of vibrations or vibrations, for example in a mass spectrometer or on a mounting unit.

The arrangement of the holding device within the central portion essentially describes the arrangement with the recess of the end faces of the multipole. The lateral location of the fixture outboard of the end faces of the multipole advantageously allows for axial reception of the multipole into a mass spectrometer, i. a recording parallel to the system axis of the mass spectrometer, whereby the multipole can be particularly easily from above into a mass spectrometer and / or removed.

According to one embodiment of the invention, the holding device has one or more positioning means with which the holding device can be aligned on a receiving device. These positioning means are manufactured with high precision, in particular with a shape and / or position tolerance from IT5 to IT11 in accordance with the ISO basic tolerances. As a result, advantageously in the installed state of the multipole, for example in a mass spectrometer, by means of the bearing surfaces and the positioning means an exact geometrisehe Location achievable in all directions of the multipole and relative to other components of the mass spectrometer. Particularly preferably, the positioning means are manufactured with ISO basic tolerances IT6 to IT8.

The International Standard Organization (ISO) defines basic tolerances with the abbreviation IT for nominal mass of 1 - 500 mm as follows: Basic tolerances IT Nominal measuring ranges in mm 1-2 > 3 -6 > 6 -10 > 10 -18 > 18 -30 > 30 -50 > 50 -80 > 80 -120 > 120-180 > 180-250 > 250 -315 > 315 -400 > 400 -500 Tolerances in μm 5 4 5 6 8th 9 11 13 15 18 20 23 25 27 6 6 8th 9 11 13 16 19 22 25 29 32 36 40 7 10 12 15 18 21 25 30 35 40 46 52 57 63 8th 14 18 22 27 33 39 46 54 63 72 81 89 97 9 25 30 36 43 52 62 74 87 100 115 130 140 155 10 40 48 58 70 84 100 120 140 160 185 210 230 250 11 60 75 90 110 130 160 190 220 250 290 320 360 400

Advantageously, the flat bearing surfaces of the holding device are also manufactured with high precision, so that together with a highly accurate receiving device produced as a perfectly fitting counterpart high-precision alignment of the multipole is made possible in its geometric position.

Advantageously, planar support surfaces are arranged on two opposite sides of the holding device, which are manufactured with high precision plane-parallel with a shape and / or position tolerance of IT5 to IT11 according to ISO basic tolerances. Furthermore, the thickness of the holding device or the height between the plane-parallel bearing surfaces is highly accurate, in particular with a shape and / or position tolerance of IT5 to IT11 according to the ISO basic tolerances manufactured.

In the attached state of the multipole is at least one flat bearing surface on the receiving device, while the opposite plane-parallel bearing surface of the holding device is not applied to the receiving device. The two plane-parallel opposite bearing surfaces advantageously allow a multi-part holding device made of identically manufactured parts, in which it is not known before assembly, which rests the flat bearing surfaces on a receiving device.

The high-precision positioning means also ensure precise alignment of the multipole in the longitudinal direction of the multipole relative to a connection axis between source, eg ion source or electron source, and detector or to an axis of a plurality of ion-optical electrodes arranged one behind the other or electron-optical components possible, which is of great importance for a high analytical measurement accuracy of the mass spectrometer.

The invention has in fact recognized that it is no longer sufficient to increase the accuracy of a multipole for increasingly higher measurement accuracies, but rather - precisely because of the ever increasing precision of the multipole - measurement inaccuracies from the comparatively less precise mounting of the multipole in the Mass spectrometer can result. The inventive precise attachment of the multipole in the mass spectrometer thus advantageously produces a further gain in measurement accuracy and sensitivity of the measuring system. Increasing the precision of the multipole thus also leads to an increase in the measuring accuracy and sensitivity of the measuring system, because a limitation of the measuring accuracy and sensitivity of the measuring system by an insufficiently precise positioning and alignment of the multipole no longer exists.

As a means of positioning any means are possible which produce a high-precision positioning and alignment of the multipole on a receiving device, such. a hole or bore which is connected to a corresponding fastener, e.g. Dowel pin or dowel screw, enable high precision positioning and alignment of the multipole, e.g. in relation to the optical axis of the mass spectrometer, which corresponds to the ideal beam path of the ions.

Further, in the inventive high-precision production of the holding device as a positioning means, the shaping of the holding device is possible if it has mating surfaces which cooperate with a corresponding shaping or mating surfaces on the receiving device.

A development of the invention provides that the holding device with the receiving device by at least one positioning means, such as a hole and / or a hole in the holding device by means of a suitable for the hole and / or bore fastener, in particular by means of dowel pin or dowel pin , Is positively connected or connected in the radial direction of the fastener.

The arrangement of hole and bore or the holes and holes of the holding device corresponds to the (geometric) arrangement of receiving holes in the receiving device, which are used to fit dowel pins or dowel pins, such that in an arrangement of the holding device on the receiving device, the holes and / or holes find a congruent counterpart in the mounting holes. The center axes of the holes and / or holes in the holding device are arranged congruent with the center axes of the receiving holes in the receiving device.

The dowel pins or dowel pin screws which connect the holding device and the receiving device are suitably designed with regard to the inner diameter of the bores and / or holes and the outer diameter of the pins, in particular with shape and / or positional tolerances according to ISO basic tolerances IT5 to IT11. This appropriate training is preferably a fit or example a press fit or a plug connection. Thus, a fast and precise alignment of the multipole in a mass spectrometer with the aid of the holding device is advantageously possible.

The running through the holes and mounting holes connection is positively formed in the radial direction of the dowel pins or with the precisely ground collar of the dowel studs, so that the dowel pins and the holes thus serve as a fitting hole. This ensures an advantageously accurate positioning of the holding device on the receiving device, wherein the accuracy depends on the selected manufacturing tolerances, but with a shape and / or position tolerance of at least ISO basic tolerances IT5 to IT11, better with ISO basic tolerances IT6 to IT8.

The arrangement of holding device and receiving device advantageously forms a system for high-precision alignment or positioning of the multipole in a mass spectrometer or on a mounting unit.

According to one embodiment of the invention, the multipole is attached to a holding device with at least one hole, which is formed as a slot, wherein the width of the elongated hole is equal to the diameter of the correspondingly arranged receiving bore in the receiving device. Likewise, the diameter of the at least one bore in the holding device is equal to the width of the hole formed as a slot. The diameters of the bores and the receiving bores are thus of equal size. The holding device is thus advantageously connected by the at least one bore and the at least one slot through pins of the same diameter into the receiving bores of the receiving device with the receiving device. The formation of the hole in the holding device as a slot thereby advantageously avoids tilting when connecting the holding device to the receiving device by means of the pins. Likewise, tilting is avoided if the pins already stuck in the receiving device and the holding device is placed on these pins.

In a further development of the invention, the holding device of the multipole is designed as a two-part device, which is arranged on in each case an electrode half-shell or a carrier element of the multipole, preferably designed as a quadrupole. Both parts of the holding device, as well as the electrode half-shells of the quadrupole, are the same. However, the invention is not limited to a two-part device as a holding device. Rather, the holding device according to the invention may also be integrally formed and then preferably arranged in the installed state of the multipole vertically below the multipole to transmit as few vibrations to the multipole.

In a two-part embodiment of the holding device, in an embodiment of the invention, both parts each have a hole, which is preferably a slot, and in each case a fitting bore. According to this embodiment of the invention, the holding device thus has two holes and two holes and the receiving device preferably four receiving bores, which are arranged such that the geometric arrangement of the mounting holes in the receiving device to the Arrangement of the holes and holes in the holding device corresponds. The diameter of the holes and the receiving holes are the same size and the hole in the holding device is preferably formed as a slot and has a width which is the same size as the diameter of the receiving holes in the receiving device. The holding device is thus connected in an advantageous manner by the two holes and the two slots through the same trained pins in or through the mounting holes through with the receiving device. These identically formed pins are preferably formed as dowel pins and each have the same length and the same diameter.

The equality of used parts for the holding device of a multipole invention and a use of the same pins leads due to higher volumes of the same (construction) parts to advantageously low production costs. Likewise, the same design of parts of a device results in a low diversity of the components, thereby advantageously simplifying the maintenance or repair of a corresponding device. This in turn leads to a reduction of costs and effort in case of maintenance or repair.

In an alternative development of the invention, a connection between the holding device and the receiving device can be produced by means of a dowel pin. For this purpose, the dowel pin on a high-precision ground collar, which advantageously has a shape and / or position tolerance according ISO basic tolerances IT5 to IT11 and fits through a corresponding hole of the holding device. By a direct attachment of the holding device to the receiving device by means of dowel pins, can be dispensed with the additional, necessary for the high-precision alignment holes and the associated dowel pins.

In a further alternative development of the invention, a connection between the holding device and the receiving device can be produced by means of a feather key. This only requires only one slot or a groove or milling in the fixture and in the receiving device. Thus, an alignment and positioning of the holding device on the receiving device by means of only one manufactured connection is possible in an advantageous manner, wherein this connection is made by means of a feather key through a slot and in a groove. The slot is formed in this case such that it has a suitably shaped to the shape of the keyway contour. This hole is introduced either in the holding device or the receiving device. In the respective other device or device, a groove or milling is introduced, which has a contour designed to match the contour of the feather key.

According to a further development of the invention, the multipole is fastened to a holding device, which can be connected to the multipole via roof-edge and prism connections, wherein the multipole can be dismantled along its central longitudinal axis into at least two sections or two carrier elements, preferably two half-shells, which likewise can be joined together via Dachkant- and prism connections. Each Dachkant- and prism connection has a roof edge structure and a prismatic structure on the electrode shells or a roof edge element on the holding device and a Prism structure on the electrode half-shell, which are formed corresponding to each other by the roof edge structure or the roof edge element roof-shaped and the prism structure are channel-shaped. In this case, the roof edge structures or roof edge elements are mutually aligned and the prism structures are each aligned with respect to a parallel to the central longitudinal axis of the multipole parallel and each roof edge structure or a roof edge element is eineinanderfügbar with a prism structure. The connecting elements or connecting surfaces of the sections of the multipole (roof edge structure and prism element) and the receiving surfaces of the holding device (roof edge element) are similar channel or roof-shaped, so that they can be joined together and produced by the same tool. Consequently, the receiving surfaces or elements of the holding device are the same as the roof edge structures of the electrode half shells as roof edge elements and are formed corresponding to the prismatic structures of the electrode half shells.

The aligned channel or roof-shaped design of the prismatic structures or roof edge structures (connecting elements) and the roof edge elements (receiving elements) and their corresponding shape advantageously ensure a guide along the alignment axis. Decisive for this function is the alignment of the two forms roof edge and prism, whereby a movement transverse to the corresponding alignment axis, which is parallel to the central longitudinal axis of the multipole in this case, prevented and thus prevented. The similar design of the roof edge structures of the electrode half shell of the multipole and the roof edge elements of the holding device ensures an advantageous same relative orientation of the multipole to the holding device with respect to this central longitudinal axis.

In order to achieve precise guidance over the guide surfaces in the context of manufacturing tolerances for shape and / or position, in particular ISO basic tolerances IT5 to IT11, particularly preferably IT6 to IT8, highly precise machining of the roof edge structures and prismatic structures formed as guide surfaces and of the roof wall element is necessary. For an advantageous parallel alignment the roof edge elements of the holding device are processed simultaneously and in the same processing step and with the same tool as the electrode half shells. This advantageously minimizes or prevents a natural accumulation of errors in the production, which are unavoidable due to the respective manufacturing tolerances of each machining and / or manufacturing process. Thus, the accuracy of the guide is within the manufacturing tolerance of the corresponding tool used to produce the surfaces. When using a precision tool, therefore, a high precision of the product can be achieved. The simultaneous production leads to an advantageously fast and thus cost-effective production. In addition, the simultaneous production and the same design of the connecting and receiving surfaces in an advantageous manner to the fact that it requires only one tool, whereby the production costs and the production cost are also reduced.

To achieve a high precision and accuracy of these surfaces is advantageously carried out by grinding. The machining by means of a grinding tool has the advantage that the machined surfaces have a very low roughness, resulting in a favorable minimum friction between the joined surfaces. In addition, by grinding a very precise machining feasible, whereby the desired high accuracy can be achieved.

According to a further development of the invention, the temperature expansion coefficient of the holding device is equal to the coefficient of thermal expansion of the carrier elements or electrode half-shells of the multipole. The holding device and the half-shells of the multipole are preferably made of metal, which has the same temperature expansion coefficient as possible within a material-specific tolerance. The material of the holding device is advantageously similar to the material of the electrode half-shells. The similarity of the two materials manifests itself in the fact that the temperature expansion coefficient of the holding device differs by at most 5%, in particular 2.5%, preferably 1%, particularly preferably 0.1% from the coefficient of thermal expansion of the electrode half-shells.

Advantageously, both materials have a low coefficient of thermal expansion, so that thermally induced expansions of the material and thus changes in length of the workpiece are minimized. The similarity, in particular equality, of the material and of the thermal properties offers the advantage that any stresses that may, for example, cause relative displacements at the connection surfaces of both devices are minimized, in particular prevented.

However, the invention is not limited to the use of equal coefficients of thermal expansion. Rather, different coefficients of thermal expansion are also possible for the carrier elements and the multipole holding device when, e.g. for reasons of cost, the holding device of a more favorable material, e.g. V2A steel, is made.

According to one embodiment of the invention, the multipole is attached to a holding device with through holes and / or threaded holes, wherein the passage and / or threaded holes of the holding device are arranged corresponding to passage and / or threaded holes of a receiving device. Thus, an advantageous locking of the holding device to the receiving device by means of a screw connection using appropriate screws, in particular by means of thin shaft screws or dowel pins, can be ensured. This locking serves to fix the holding device perpendicular to the radial direction of the passage and / or threaded holes. In the present case, this is a fixation along an axis which is perpendicular to a plane which completely contains the central longitudinal axis of the multipole. Thus, the number of degrees of freedom or free directions of movement is reduced. In particular, the holding device preferably has two, in particular three, in particular four, through holes or threaded bores and the receiving device has passages or threaded bores arranged correspondingly to these through bores or threaded bores, in particular congruent ones.

Preferably, a respective threaded bore with a through hole corresponds to fix the holding device to a receiving device by means of a screw. If tapped holes or partial threaded bores are provided both in the holding device and in the receiving device, the fixation is preferably carried out by means of suitable thin-shaft screws in which a part of the thread or the threadless area is turned off and have only in the region of the corresponding threaded bore a corresponding mating thread. Such thin shaft screws are advantageously captive mountable.

In an alternative development of the invention, a locking of the holding device on the receiving device can also be realized by means of a clamping closure. Such a locking system preferably has a clamping hook and a counter hook, which may be pronounced as a bracket, clamp or lever.

In a further embodiment of the invention, the multipole has a holding device which is inextricably connected to at least one carrier element or at least one electrode half-shell of the multipole and manufactured together with them. This can be realized in particular by means of casting, milling from a block of material or sintering. During casting, for example, a holding device is already provided in the casting mold for the electrode half-shell. Alternatively, an electrode half shell is welded as a semifinished product or precursor with the holding device prior to their further processing.

In the case of the multipole according to the invention, at least two, three or more of the developments described above can be combined with one another in order to obtain meaningful feature combinations within the scope of the invention.

Furthermore, o.g. Problem solved by means of a holding device of a multipole, in particular quadrupole, wherein the holding device can be arranged on a receiving device of a mass spectrometer, a mounting unit and / or one of the maintenance or repair of the multipole serving unit. The holding device preferably has at least one roof edge structure and at least one prism structure for fastening the holding device to the multipole. The holding device according to the invention thus serves for the high-precision alignment, positioning and holding of the multipole, for example a quadrupole, e.g. in a mass spectrometer or on a mounting unit.

Furthermore, o.g. Task solved by means of a mass spectrometer with a multipole according to the invention and with a receiving device for receiving the holding device of the multipole, wherein by means of the holding device of the multipole of the multipole in an exact geometric position relative to all axial directions of the multipole and relative to other components of the mass spectrometer is preserved. As a result of the high-precision alignment and positioning of the components of the mass spectrometer manufactured with high precision, the resolution, sensitivity and performance of the mass spectrometer can advantageously be increased overall in order to advantageously contribute to increasing the measuring accuracy of mass spectrometers.

Furthermore, the above object is achieved by means of a mounting unit with a receiving device for positioning a holding device relative to the multipole, in particular quadrupole solved.

The assembly unit according to the invention with a receiving device for positioning a holding device relative to the multipole provides that the mounting unit has a bottom plate. This bottom plate is aligned perpendicular to the central longitudinal axis of the multipole disposed on the receiving device of the mounting unit and parallel to the effective direction of gravity. Such an embodiment of a mounting unit allows an advantageous precise positioning of the holding device relative to the multipole and the carrier elements or electrode half-shells of the multipole to each other. Thus, a precise alignment and holding of the multipole according to the invention by means of the holding device is advantageously made possible in a mass spectrometer.

Advantageously, in addition, an exact positioning of the electrodes to each other, in particular the beginning and end points of their sections, can be ensured, whereby disturbances of the electric field in the multipole are reduced.

According to one embodiment of the invention, the assembly unit according to the invention comprises a rear wall, which has recesses, in particular hole-shaped recesses. Through these hole-shaped recesses there is a line of sight from the outside through the rear wall of the mounting unit on the preferably formed as screw connection elements of the holding device and the multipole and / or the electrode half-shells of the multipole. This visual connection ensures accessibility of the screw, in particular the screws, through these recesses, for example with a screwdriver.

Due to the use of the mounting unit for positioning the holding device relative to the multipole and the electrode half-shells of the multipole to each other, the mounting unit can also be referred to as a positioning unit.

The use of a mounting unit has the advantage that the holding device and the half-shells of the multipole can be mounted within this unit and thus can be aligned with one another. Thus, a kind of calibration of the positioning of the holding device relative to the multipole and thus a prior alignment before the installation of the holding device and the multipole in the mass spectrometer. For this purpose, the mounting unit comprises a receiving device according to the invention, a bottom plate, which ensures an exact alignment of the electrodes to each other, and corresponding recesses, which allow the accessibility of screws. These screws serve to lock the precise positioning of the holding device relative to the multipole and possibly the electrode half-shells of the multipole to each other.

Thus, advantageously, alignment and accurate positioning of the fixture relative to the multipole prior to insertion or installation into the mass spectrometer are possible.

Further developments of the invention will become apparent from the claims, the description and the drawings. The aforementioned advantages of features and of combinations of several features are exemplary and may come into effect alternatively or cumulatively without the advantages being compelling of embodiments of the invention must be achieved. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or features of different claims is also possible deviating from the chosen back-relationships of the claims and is hereby proposed. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features may also be combined with features of various claims. Likewise, claims listed in claims can be omitted for further embodiments of the invention.

Fig. 1a-d

eine Haltevorrichtung eines erfindungsgemäßen Multipols aus verschiedenen Perspektiven,

Fig. 2a-c

eine Elektrodenhalbschale eines Quadrupols zusammen mit einer Haltevorrichtung aus verschiedenen Perspektiven,

Fig. 3a

ein zwei Elektrodenhalbschalen umfassender Multipol zusammen mit einer Haltevorrichtung in perspektivischer Ansicht,

Fig. 3b

ein zwei Elektrodenhalbschalen umfassender Multipol zusammen mit einer Haltevorrichtung in seitlicher Ansicht entlang der Mittellängsachse des Multipols,

Fig. 4

eine seitliche Ansicht eines zwei Elektrodenhalbschalen umfassenden Multipols zusammen mit einer Haltevorrichtung an bzw. auf einer Aufnahmeeinrichtung,

Fig. 5

eine frontale Ansicht einer leeren Montageeinheit ohne Multipol und Haltevorrichtung,

Fig. 6a,b

eine seitliche und eine frontale Ansicht der Montageeinheit mit Multipol und Haltevorrichtung,

Fig. 7a-d

mehrere Ausführungsbeispiele für eine Haltevorrichtung,

Fig. 8a-d

mehrere Ausführungsbeispiele für in die Haltevorrichtung eingebrachten Löcher und Bohrungen,

Fig. 9

der Multipol gemäß Fig. 4 ohne Aufnahmeeinrichtung mit übertrieben dargestellt ungenau gearbeiteten äußeren Konturen der Elektrodenhalbschalen und

Fig. 10

der Multipol gemäß Fig. 9 ohne die in Fig.9 dargestellte erfindungsgemäße Haltevorrichtung, jedoch mit einer herkömmlichen ringförmig ausgebildeten Haltevorrichtung zur Veranschaulichung eines unerwünschten Versatzes des gemeinsamen Mittelpunkts der Elektroden des Multipols gegenüber dem Mittelpunkt der äußeren Kontur der Elektrodenhalbschalen.

Further embodiments of the invention will become apparent from the claims and from the embodiments explained in more detail with reference to the drawing. In the drawing show:

Fig. 1a-d

a holding device of a multipole according to the invention from different perspectives,

Fig. 2a-c

an electrode half shell of a quadrupole together with a holding device from different perspectives,

Fig. 3a

a multipole comprising two electrode shells together with a holding device in perspective view,

Fig. 3b

a multipole comprising two electrode shells together with a holding device in a side view along the central longitudinal axis of the multipole,

Fig. 4

a side view of a multipole comprising two electrode half-shells together with a holding device on or on a receiving device,

Fig. 5

a frontal view of an empty assembly unit without multipole and holding device,

Fig. 6a, b

a lateral and a frontal view of the assembly unit with multipole and holding device,

Fig. 7a-d

several embodiments of a holding device,

Fig. 8a-d

several embodiments of holes and bores introduced into the holding device,

Fig. 9

the multipole according to Fig. 4 without recording device with exaggerated inaccurate outer contours of the electrode half shells and

Fig. 10

the multipole according to Fig. 9 without the in Figure 9 illustrated holding device according to the invention, but with a conventional annular holding device for illustrating an undesirable offset of the common center of the electrodes of the multipole with respect to the center of the outer contour of the electrode half-shells.

Like reference numerals in the figures indicate like parts. Further letters behind a reference number indicate further exemplary embodiments of the corresponding part.

Fig. 1a-d show a possible embodiment of a holding device 10 of a multipole according to the invention, as for example. In Fig. 3a shown by the reference numeral 32. In the FIGS. 1a-d However, only a part 10 a of the two-part holding device 10 is shown.

Fig. 1a shows a particularly preferred embodiment of the holding device 10a in perspective View. It describes a U-shape, wherein two supports 12, the mutually parallel sides of the U-shape, and a support connection 14 forms the lower part of the U-shape, which connects the parallel sides of the U-shape and thus the supports 12. The supports 12 have as positioning each a bore 16 and a hole 18 and two passage and / or threaded holes 20.

The surfaces of the supports 12 have a first bearing surface 13 and a second bearing surface 15, which are formed as highly precisely machined, planar surfaces plane-parallel to each other. These bearing surfaces 13, 15 are preferably manufactured with respect to their nominal dimensions according to ISO basic tolerances IT5 to IT11. Furthermore, these bearing surfaces 13, 15 also have high-precision positional tolerances with respect to the parallelism of the two bearing surfaces 13 and 15 with respect to one another and with respect to the perpendicularity between the bearing surfaces 13, 15 and the positioning means.

The bore 16 is formed in this embodiment as a bore which serves a later accurate positioning of the holding device 10a. The bore 16 is preferably located in a further component, on which the holding device 10a is to be aligned and positioned, a corresponding counterpart, so that a radially in the bore 16 positively formed, in the bore 16 matching pin through the bore 16 and the corresponding Counterpart can be inserted through.

The hole 18 is formed in this preferred embodiment as a slot having the same width as the diameter of the bore 16. The passage and / or threaded holes 20 are used to attach the holder 10 a to another component.

The preferred holding device 10a also has roof edge elements 22 with roach tapped holes 24. Each roof edge element 22 has two mutually angled surfaces, a narrow roof edge 21 and a broad roof edge 23, each with the same pitch. These Dachkantflanken 21 and 23 are high precision, preferably by grinding, processed. Via a preferably angled side surface 19, the surface of the angularly arranged, opposite the narrower edge of the roof edge 21 wider roof edge 23 of the holding device 10a with the first bearing surface 13 of the holding device 10a has a connection.

Fig. 1b shows a side view of the same preferred embodiment of the holding device 10a as in Fig. 1a , This illustration highlights the formation of the bore 16, formed as a slot hole 18, the passage and / or threaded holes 20 and the roof edge threaded holes 24. The mutually angled roof edge edges 21 and 23 form the roof edge element 22. The roof edge element 22 has a roof edge threaded bore 24, by means of which the holding device 10a can be fastened to a corresponding further device by means of screws.

Fig. 1c shows a side view of the longitudinal side of the same holding device 10a as in Fig. 1a , b. This illustration shows that the height or thickness of the supports 12 is a multiple of the height or thickness of the support connection 14. The height or thickness of a support 12 is determined by the distance of first bearing surface 13 defined to the second bearing surface 15 of the holding device 10a.

The different thickness of the overlay 14 compared with the pads 12 is used advantageously the material savings. Furthermore, the small thickness of the overlay connection 14 advantageously allows, to some extent, the absorption of torsional movements. The overlay joint 14 serves to hold the pads 12 at a predetermined distance and a predetermined position to each other. The bearing surfaces 13 and 15 of the supports 12 are formed exactly parallel to one another, so that these surfaces must be precisely machined. The production of these surfaces is preferably carried out by means of milling and / or grinding.

Fig. 1d FIG. 12 shows a side view transverse to the longitudinal direction of the same preferred holding device 10a as in FIG Fig. 1a-c , Here it can be seen that the supports 12 are formed thicker than the height of the roof cladding element 22, wherein the height of the roof cladding element 22 is determined by the distance of the support surface 15 to vertex 25 of the roof-shaped side of the roof cladding 22. The mutually angled roof edge edges 21 and 23 have a predetermined angle and an axis of symmetry, wherein the axis of symmetry extends through the vertex 25 of the roof edge shape. This angle between the symmetry axis of each one of the roof edge flanks 21 and 23 of the roof wall element 22 is preferably 120 °, in particular 110 °, in particular 130 °.

The holding device according to the invention Figure 1a-d is preferably made of a workpiece. This production is preferably carried out by milling. Surfaces requiring precise machining with high accuracy and / or low surface roughness are further processed by grinding.

Fig. 2a shows a perspective view of a support member or an electrode half shell 26 of a multipole with two arranged on the electrode half-shell 26 electrodes. In this case, the blackened surfaces represent essentially hyperbolically shaped surfaces, which determine the course of the field within the quadrupole, of these electrodes.

Further shows Fig. 2a a holding device 10a, which is arranged on a carrier element or an electrode half shell 26 of a multipole. As well as in Fig. 1a-d shows Fig. 2a a preferred embodiment of the holding device 10. Other embodiments of the holding device 10 are also applicable to the following explanations.

The half-shell electrode 26 has connecting elements, which are formed as a roof edge structure 28 and prism structure 30. The roof edge structures 28 and prism structures 30, as well as the roof edge element 22 of the holding device 10a in Fig. 1a-d , Two mutually angled surfaces arranged on each with the same slope. On one side of the electrode half shell 26 only roof edge structures 28 are arranged and on the other, opposite side of the electrode half-shell 26 exclusively prism structures 30 are arranged. The roof edge structures 28 and prism structures 30 are formed corresponding to one another in such a way that in each case a roof edge structure 28 and a prism structure 30 into each other to a roof edge and prism joints 31 are available. The prismatic structures 30 have a channel-shaped or convex shape. The number of prismatic structures 30 is the sum of the number of fabricated roof edge structures 28 and the number of roof edge elements 22 of a holding device 10 a to be fastened to the electrode half-shell 26. The Dachkant- and prismatic connections 31 thus serve on the one hand the joining of two half-shells electrode 26 to a multipole and on the other fastening a holding device 10a to an electrode half shell 26, wherein each a roof edge element 22 of the holding device 10a in each case a prism structure 30 is joined. The attachment of the holding device 10a to the electrode half-shell 26 via Dachkant- and prismatic connections 31 advantageously allows a micrometer exact positioning of the holding device 10a to the center of the multipole, or to the central longitudinal axis of the multipole and thus an exact positioning of the multipole in a mass spectrometer.

Fig. 2b shows a side view of the electrode half-shell 26 with the preferred holding device 10a. The roof edge element 22 of the holding device 10a can be inserted into the prism structure 30 of the electrode half-shell 26 on the basis of its shape corresponding to the prism structure 30. According to the invention, the broad roof edge 23 of the roof cladding element 22 is orientated in the direction of the support surface 13 and wider than the narrow roof edge 21 of the roof cladding element 22. This results in the roof edge 23 after the roof cladding element 22 of the holding device 10a is fitted into the prism structures 30 of the electrode half shell 26 beyond the outside of the electrode half-shell 26 also protrudes. This has the advantage that tilting of the roof cladding element 22 on the prism structure 30 and thus of the holding device 10a on the electrode half-shell 26 is prevented.

Fig. 2c shows a plan view of an electrode half-shell 26 with the electrodes attached to the electrode half-shell 26 and a holding device 10a in the same embodiment as in Fig. 2a and 2b , Again, as in Fig. 2a shown in black, the substantially hyperbolic shaped surfaces of the electrodes.

The supports 12 of the holding device 10a hide in this plan view the two further prismatic structures 30 which serve to secure the holding device 10a. Thus, in each case the same number of roof edge structures 28 and prismatic structures 30 is visible. The holding device 10a can be fastened by means of screws through connecting bores 29 in the prismatic structures 30 by means of the roof edge threaded bores 24 in the holding device 10a to the electrode half-shell 26. The roof edge structures 28 of the electrode half-shell 26 have connection threaded bores 27, which are preferably of the same design as the roof-edge threaded bores 24 of the holding device 10a.

Fig. 3a shows two joined to a multipole electrode half-shells 26, each with a holding device 10 a attached thereto of the embodiment according to Fig. 2a-c , Such a multipole 32 is preferably designed as a quadrupole. Fig. 3a shows such a preferred quadrupole, which comprises two of the electrode half-shells 26, with a two-part holding device 10a. Depending on the part of the holding device 10a is on the roof edge elements 22 on the prismatic structures 30 laterally one Electrode half-shell 26 is arranged and fixed. The electrode half-shells 26 are connected to one another via the roof edge structures 28 and the prism structures 30, wherein a respective roof edge structure 28 is joined into a prism structure 30. One rooftop structure 28 with a prismatic structure 30 forms a rooftop and prismatic connection 31 joined to one another. The rooftop and prismatic connections 31 can be fixed by means of screws 33. The wider compared to the narrow roof edges 21 training the Dachkantflanken 23 is used advantageously to ensure a defined distance of the bearing surfaces 13 of the pads 12 to the Dachkant- and prismatic connections 31.

Fig. 3b shows a side view along the central longitudinal axis of the assembled to a multipole electrode half-shells 26 26 each having a holding device 10a as in Fig. 3a , The side view shows the connections of the assembled half-shells 26 formed as a roof edge and prismatic connection 31. Thus, only one of the two fixed holding devices 10a is visible in this view. The second holding device 10a is located just behind the in Fig. 3b visible holding device 10a. Each of the joints of a roof edge structure 28 and a prism structure 30, which are each joined to a roof edge and prism joint 31, is fixed with one screw 33 each. For this purpose, a connecting bore 29 is introduced into each prism structure 30 and a connecting threaded bore 27 is introduced into each roof edge structure 28. These connecting threaded bores 27 of the electrode half-shell 26 are preferably designed in the same way as the roof-tapped threaded bores 24 of the holding device 10a. Thus, in an advantageous manner, the holding device 10a can be fixed by means of the same screws 33 via the prismatic structures 30 to the electrode half-shells 26 like the half-shells 26 of the electrodes.

The holding device 10a fastened to the electrode half-shell 26 has an assembly spacing 34 relative to the respective other half-shell of the electrode. As a result, the holding device 10a can also be connected to the prism structures 30 after the half-shells 26 have been assembled, wherein the holding device 10a is inserted into the prism structures 30 by means of lateral insertion along the alignment of the roof edge elements 22, which are aligned parallel to the longitudinal direction of the multipole 32 becomes.

Preferably, the holding device 10a has at least one roof edge structure 28, which can be connected to a correspondingly formed prism structure 30 of the electrode half-shell 26. Thus, it is advantageously possible to produce a holding device 10 by means of already known and existing tools for producing and processing the electrode half-shells 26.

Fig. 4 shows a multipole 32 with a two-part holding device 10a, which is arranged on a receiving device 36. The holding device 10a and thus the multipole 32 is connected by means of fastening elements 38, in particular dowel pins, with the receiving device 36. Such a receiving device 36 is, for example, arranged in a mass spectrometer.

This in Fig. 4 shown view of the end face of the multipole 32 shows the inventive arrangement of the holding device 10a in the receiving device 36, which is characterized by the following features distinguished:

The holding device 10a is arranged laterally of the multipole 32 in the region of a cylinder jacket surface enveloping the multipole 32, wherein the vertical extent or thickness of the supports 12 of the holding device 10a is advantageously dimensioned such that a plane passing through the center of the circular cross section of the multipole 32 extending straight, equally a plane of symmetry of the cylindrical shape of the preferred multipole 32 in Fig. 4 is, as well as the holding device 10a divided into two parts of the same vertical extent or thickness. Due to the advantageous embodiment and arrangement of the holding device 10a on the multipole 32, in which the flat support surfaces 13, 15 of the supports 12 are rotationally asymmetric to the central longitudinal axis of the multipole 32, it is ensured that the multipole 32 parallel to a plane which of the lying Surface of the supports 12 of the holding device 10a is clamped, is aligned. The supports 12 of the holding device 10a may be arranged on or in a corresponding receiving device 36.

Fig. 5 shows a frontal view of a preferred mounting unit 40. The mounting unit 40 preferably has a bottom plate 42, a rear wall 44 and a receiving device 36a for a holding device 10a. Such a mounting unit 40 is used to mount the holding devices 10a according to the FIGS. 1a-d . 2a-c and 3a-b on a multipole 32 and possibly the electrode half-shells 26 to each other.

The receiving device 36a according to the embodiment shown here has four receiving holes 46 and four receiving threaded holes 48. The receiving bores 46 and the receiving threaded bores 48 of the receiving device 36a are arranged such that they correspond to the arrangement of the bores 16, holes 18 and passage and / or threaded bores 20 of the holding device 10a. In addition, the diameters of the bores 16 in the holding device 10a and the mounting holes 46 in the mounting unit 40 and the diameter of the through and / or threaded holes 20 in the holder 10a and the female threaded holes 48 in the mounting unit 40 are the same size. The rear wall 44 has advantageously recesses 50, which allow the introduction of a tool, preferably a screwdriver.

Fig. 6a shows a side view of the preferred mounting unit 40 according to Fig. 5 with a multipole 32 and a holding device 10a. The holding device 10a is connected to the receiving device 36a by means of at least two, preferably four, pins 38. This connection of the pins 38 through the bores 16 in the holding device 10a and the receiving bores 46 of the receiving device 36a is formed in a form-fitting manner in the radial direction of the pins 38. Preferably used for producing such a positive connection correspondingly formed dowel pins which extend through the formed as a fitting bore holes 16 in the holding device 10 a and the receiving holes 46 in the receiving device 36 a.

Fig. 6b shows a frontal view of the same construction as in Fig. 6a which has a mounting unit 40 with a receiving device 36a, a bottom plate 42, a rear wall 44 with recesses 50 as well a multipole 32 with a holding device 10 a, which is arranged by means of appropriately trained pins 38 on the mounting unit 40 includes. Recesses 50 are due to the arrangement of the multipole 32 in the mounting unit 40 in this view, which in Fig. 6b is shown, not visible. The holes 18 formed in the holding device 10a as elongated holes advantageously enable a locking or arrangement of the holding device 10a on the receiving device 36a, without there being any jamming. The mounting unit allows the positioning of the holding device 10a relative to the multipole 32. The procedure is as follows:

The electrode half-shells 26 are already loosely connected to one another and to the holding device 10a. By means of at least two pins 38, the holding device 10a is connected by a respective hole 18 and a bore 16 with the receiving device 36a. To fix this connection 40 fixing screws 52 can be introduced into the through and / or threaded holes 20 of the holding device 10a and the passage and / or receiving threaded holes 48 in the receiving device 36a of the mounting unit.

For fixing via a respective threaded bore 20 and part threaded hole with a corresponding receiving threaded bore 48, a thin shaft screw is used as a fixing screw 52 with a partial thread, which only in the area Receiving threaded bore 48 has a thread.

After reaching a predetermined relative position of the holding device 10a to the multipole 32, this is fixed accordingly. This fixation is carried out in this preferred embodiment by means of screws 33. The screws 33 are for this purpose for fixing the electrode half-shells 26 introduced to each other through the connecting holes 29 of the electrode half-shells 26 in the connecting threaded holes 27 of the electrode half-shells 26.

To fix the holding device 10a on the half-shell electrode 26, the screws 33 are introduced through the connecting holes 29 of the electrode half-shells 26 in the roof edge threaded holes 24 of the holding device 10a. After carrying out the fixation, the desired positioning of the holding device 10a with respect to the multipole 32 is completed. Thus, the multipole 32 is aligned by means of the holding device 10a according to the invention in a predetermined position in the mass spectrometer and quickly and easily installed in the mass spectrometer.

The FIGS. 7a-d show various embodiments of a holding device 10 according to the invention on a multipole 32, wherein the list of embodiments is not exhaustive:
Fig. 7a shows a multipole 32 with a two-part holding devices 10a of the preferred embodiment, as in the previous FIGS. 1a-d . 2a-c . 3a-b, 4 and 6a-b were shown. Each of the two parts of the holding device 10a is preferably made of a respective workpiece, in particular milled. The holding device 10a describes a U-shape, wherein the mutually parallel portions of the U-shape the Formations 12 which are connected to each other by means of a support connection 14 and in a fixed relative position.

The supports 12 are thicker than the support connections 14. The supports 12 are made such that they provide high-precision, flat support surfaces 13 and 15. This requires a precise production of the surfaces of the support surfaces 13 and 15 of the supports 12 with respect to the form and / or position tolerances, in particular with an ISO basic tolerance of IT5 to IT11.

In a preferred embodiment, the surfaces of the bearing surfaces 13 and 15 are machined by machining techniques, e.g. Sawing, milling, machining. In order to meet the requirement of high precision in production, machining by means of milling is preferably selected for the bearing surfaces 13 and 15. The processing of the support connections 14 requires compared to the support surfaces 13 and 15, a lower precision, since these serve primarily to ensure a fixed axial distance and a desired position of the supports 12 to each other and to be able to define.

In Fig. 7b For example, a holding device 10b for holding a multipole 32 with a total of four parts, preferably identical to each other, is shown. Such a holding device 10b has no support connection 14 compared with a holding device 10a. The holding device 10b comprises four supports 12 without a support connection 14. This embodiment has the advantage that at least four of the parts of the holding devices 10b can be produced from a material piece of the same size as the material piece from which two of the parts of the holding devices 10a were manufactured. This leads to an advantageous material saving of 50-70% and thus also to a reduction of the workload.

Fig. 7c shows a further embodiment of a holding device 10 according to the invention for holding a multipole 32. In this case, the multipole 32 is connected to three parts of the holding device 10b, whereby a further material savings with a guarantee of a stable position of the multipole 32 is achieved. However, this material saving has the consequence that the arrangement of the supports is not symmetrical with respect to an axis of symmetry which runs parallel to the central longitudinal axis of the multipole 32. Thus, the electrode half-shells 26 of the multipole 32 would each have a different number of roof edge and prism connections 31.

Fig. 7d shows a further embodiment of the holding device 10 according to the invention. In this case, the multipole 32 has two identically formed parts of a holding device 10c, which comprises no support connections 14. The parts of the holding device 10 c are aligned centrally along the central longitudinal axis of the multipole 32 and attached to the electrode half-shells 26. The width or size of the supports 12 of the holding device 10c is designed such that in each case a sufficient for a stable position bearing surface 13 and 15 is ensured. However, this embodiment of the holding device 10c requires a very high precision in the production of the bearing surfaces 13 and 15, resulting in higher production costs.

Alternatively to the comments according to Fig. 7a-d is also a one-piece use of a holding device 10 according to one of the embodiments 10a-c possible. When mounted with only a one-piece holding device 10, this holding device 10a-c is preferably arranged in the installed position of the multipole 32 in a mass spectrometer vertically below the multipole 32 in the direction of the central longitudinal axis of the multipole 32 to allow little vibration or vibration on the multipole 32 transfer.

The Fig. 8a-d show several embodiments of the holes 16, holes 18 and through holes and / or threaded holes 20, which in the preferred embodiment of the holding device 10a according to Fig. 1a-d be introduced. The corresponding variants of the exemplary embodiments are identified by the addition of dashes to the reference numeral 10a: eg 'for the first alternative variant,' for the second alternative variant, etc.

Fig. 8a shows the two parts of the holding device 10a, each with a hole formed as an elongated hole 18, a bore 16 and two passage and / or threaded holes 20. The passage and / or threaded holes 20 serve to fix the holding device 10a in the receiving device 36th

Fig. 8b shows the same geometric arrangement of the holes 18 and holes 16 as in Fig. 8a , However, in this first alternative variant of the embodiment, the passage and / or threaded bores 20 are missing. According to this embodiment, the fixing of the holding device 10a 'to a receiving device 36 is thus realized, for example, by means of a clamping closure. Such a tension lock has the advantage that the multipole 32 attached to the holding device 10a ', which is arranged, for example, in a mass spectrometer, can be exchanged easily and quickly.

Fig. 8c shows a variant of the introduction of the holes 18 and holes 16 in the holding device 10a 'and 10a "." In the holding device 10a' is a respective hole 18, preferably a slot, and a bore 16, as in Fig. 8b , brought in. The holding device 10a "in turn has neither a hole nor a bore, thus the multipole 32 is locked and centered only by means of one of the two holding devices 10a 'and 10a".

Fig. 8d shows a further variant, wherein the holding device 10a '"has a preferably designed as a slot hole 18 and the second holding device 10a'" has a bore 16. The hole 18 and the bore 16 are arranged to each other such that they lie on a diagonal with respect to the central longitudinal axis of the multipole 32.

The fixing of the holding device 10a 'to 10a "" on the receiving device 36 takes place according to the Fig. 8c and 8d analogous to Fig. 8b by means of a tension lock. In the event, however, that a fixation via at least one fixing screw 52 takes place, additional through holes and / or threaded holes 20 in the holding devices 10a 'to 10a "" provided, however, in Fig. 8c and 8d are not shown.

At the in Fig. 8a-d shown embodiments of the holes 16, holes 18 and through holes and / or threaded holes 20, these can also be combined for the use of a single fastener 38, whereby the use of a dowel pin as a fastener 38 is possible.

Fig. 9 shows the multipole 32 according to Fig. 4 without the in Fig. 4 Shown receiving device 36. The outer contours of the electrode half-shells 26 are shown exaggerated inaccurate work. The two parts 10a of the holding device 10 are attached to surfaces of the prismatic structures 30 which are processed together in one working step with the electrodes 26A, 26B of an electrode half-shell 26. For this purpose, these electrodes 26A, 26B are first attached via insulators 54 with half-shell elements 56, for example glued. This processing is done, for example, with a single grindstone. Thus, a precise position of the machined surfaces of the electrodes 26A, 26B and the surfaces of the prismatic structures 30 to each other is ensured.

As a result of this precise arrangement of the surfaces of the prismatic structures 30, the parts 10a of the holding device 10 can also be aligned very precisely with the processed electrode surfaces. This allows an exact spacing of the dowel holes 16 to the center M of the processed electrode surfaces. The Multipole can thus be easily installed and aligned in a high-precision manner in the mass spectrometer.

Fig. 10 shows the multipole according to Fig. 9 without the in Figure 9 illustrated holding device according to the invention, but with a conventional ring-shaped holding device 58 for illustrating an undesirable offset X in the x direction and Y in the y direction of the common center M of the processed electrode surfaces of the multipole 32 with respect to the center N of the outer contour of the electrode half-shells 26 and thus the conventionally attached to this outer contour annular holding device 58. Such an offset can be avoided thanks to the invention. The invention therefore contributes to significantly increase the measurement accuracy of mass spectrometers.

Claims (15)

Multipole with a holding device (10) arranged thereon for holding the multipole (32), for example a quadrupole in a mass spectrometer,
characterized in that
the holding device (10) has one or more flat bearing surfaces (13, 15) for fastening the multipole (32) to a receiving device (36, 36a) for receiving the holding device (10) and
the holding device (10) is arranged on surfaces (30) of the multipole (32), which are manufactured together in one working step with electrodes (26A, 26B) of the multipole. Multipole according to Claim 1, characterized in that the holding device (10) is arranged laterally of the multipole (32) in the region of a cylinder jacket surface enveloping the multipole (32). Multipole according to claim 2, characterized in that the holding device (10) is arranged in a central portion of the enveloping cylinder jacket surface , said central portion is symmetrical to the central transverse axis of the multipole (32) and corresponds to a maximum of 90% of the cylinder jacket surface. Multipole according to one of the preceding claims, characterized in that the holding device (10) has one or more positioning means and
the holding device (10) can be aligned by means of this positioning means on a receiving device (36, 36a). Multipole according to claim 4, characterized in that at least one positioning means of the holding device (10) through a hole (18) and / or a bore (16) in the holding device (10) is formed and
the holding device (10) with the receiving device (36, 36a) by means of a for the hole (18) and / or the bore (16) suitably formed fastener (38), such as dowel pin or dowel pin, in the radial direction of the fastener (38) positively can be connected, wherein the arrangement of the at least one positioning means in the holding device (10) with the arrangement of at least one receiving element, for example, receiving bore (46), in the receiving device (36, 36a) corresponds. Multipole according to claim 5, characterized in that the holding device (10) has at least one hole (18) which is formed as a slot, wherein the width of the elongated hole in the holding device (10) equal to the diameter of the correspondingly arranged receiving bore (46) in the receiving device (36, 36 a) and is equal to the diameter of the at least one bore (16) in the holding device (10) is formed. Multipole according to one of the preceding claims, characterized in that the holding device (10) via Dachkant- and prismatic connections (31) with the Multipol (32) is connectable and the multipole (32) along its central longitudinal axis in at least two sections, preferably two electrode half-shells (26), which can also be joined together via roof edge and prism connections (31), each roof edge and prism connection (31) having either a roof edge structure (28) and a prism structure (30) on the electrode half shells (26) or a roof edge element (22) on the holding device (10) and a prism structure (30) on the electrode half shells (26) which are formed corresponding to each other by the roof edge structure (28) or the roof edge element (22) roof-shaped and the prism structure (30) channel-shaped are, wherein the roof edge structures (28) or roof edge elements (22) to each other and the prism structures (30) aligned with each other with respect to a central longitudinal axis of the multipole (32) parallel parallels and each a roof edge structure (28) or a roof edge element (22) with a Prism structure (30) are interlocked. Multipole according to one of the preceding claims, characterized in that the holding device (10) through and / or threaded holes (20), wherein the through and / or threaded holes (20) of the holding device (10) to receiving threaded holes (48) of a receiving device (36, 36a) are arranged correspondingly. Multipole according to one of the preceding claims, but without reference to claim 7, characterized in that the holding device (10) is inextricably linked to at least one electrode half shell (26) of a multipole (32) and is manufactured together with this. Holding device of a multipole (32) according to one of claims 1 to 8, wherein the holding device (10) on a receiving device (36, 36a) of a mass spectrometer, a mounting unit (40) and / or one of the maintenance of the multipole (32) serving unit can be arranged is and
the holding device (10) has at least one roof edge structure (28) and / or at least one prism structure (30) for attachment to the multipole (32). Mass spectrometer with a multipole (32) according to one of claims 1 to 9, and a receiving device (36) for receiving a holding device (10) of the multipole (32), in particular according to claim 10, wherein by means of the holding device (10) of the multipole (32 ) this multipole (32) is arranged in an exact geometrical position relative to all axial directions of the multipole (32) and relative to other components of the mass spectrometer in the mass spectrometer. Mounting unit with a receiving device (36 a) for positioning a holding device (10) relative to a multipole (32) according to one of claims 1 to 9, wherein the mounting unit (40) has a bottom plate (42) which is aligned such that the central longitudinal axis of a on the receiving device (36a) of the mounting unit (40) can be arranged multipole (32) and the effective direction of gravity are aligned perpendicular to the bottom plate (42). Mounting unit according to claim 12, characterized in that the mounting unit (40) has a rear wall (44) which recesses (50), for example, hole-shaped recesses, through which connecting elements of the holding device (10) with the multipole (32) and / or the electrode half shells (26) of the multipole (32) are visible and accessible with a tool. Method for positioning a holding device (10) relative to a multipole (32) according to one of claims 1 to 9 by means of a mounting unit (40) according to one of claims 12 or 13, comprising the following steps: - Form-fitting connection of the holding device (10) with the associated receiving device (36 a), - Moving the multipole (32) relative to the holding device (10) in the longitudinal direction of the multipole (32) until a predetermined relative position of the multipole (32) to the holding device (10) is reached, and - Fixing this relative position, for example by means of screwing, clamping, jamming, gluing, clamping, welding and / or soldering. A method according to claim 14, characterized in that the positive connection of the holding device (10) with the receiving device (36a) by means of at least two positioning means, such as dowel pins or dowel pin, takes place, each positioning means in each case a receptacle, such as receiving bore (46), hole (18) and / or bore (16) is introduced.

Images