CN111308539B

CN111308539B - Alpha beta measuring instrument

Info

Publication number: CN111308539B
Application number: CN202010215389.7A
Authority: CN
Inventors: 乐爱兵; 涂德海; 张阳天; 薛斌; 刘维娟; 龙文琼; 宗忻
Original assignee: Foundmacro Co ltd
Current assignee: Foundmacro Co ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2021-11-23
Anticipated expiration: 2040-03-24
Also published as: CN111308539A

Abstract

The invention discloses an alpha beta measuring instrument, which comprises: a guard including a first grid and a first positioning element; a light shielding member disposed adjacent to the shielding member, including a fixing member and at least one film layer mounted to the fixing member, the fixing member including a second grid and a second positioning element, and an orthographic projection of the first grid and the second grid in a direction in which the radiation is incident; and a seal positioning member including a fixing part engaged with the first positioning element and the second positioning element, the fixing part being arranged to fix the light shielding member and the shielding member in the α β meter.

Description

Alpha beta measuring instrument

Technical Field

The present disclosure relates to the field of nuclear radiation detection technology, and more particularly, to an α β measurement instrument.

Background

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

The α β measuring instrument is a common nuclear radiation detecting instrument, and can measure α and β surface activities of personnel, equipment and various object surfaces. The detector generally adopts a double-scintillation technology and mainly comprises a shell, a protective layer, a silica gel sealing sleeve, a light shielding layer, a plastic scintillator, a photomultiplier and a hardware module.

A film-fixing sheet, which is generally thin stainless steel, and an aluminized polyester film are generally used in the light-shielding layer. To avoid blocking of α and β rays, the central detection area of the fixing plate is generally designed to be hollowed out, so that the aluminized polyester film of the light shielding layer and the film fixing plate can only be bonded through the periphery, but this would result in: due to the fact that the bonding area is not enough, the flatness of a film in a detection area of the light-shielding layer is poor, the problem that wrinkles are prone to occur in the middle part is solved, and the appearance of a detection instrument is seriously influenced; in addition, the shading layer has poor strength and is easy to deform; when light-resistant layer is bigger, because the material is too soft, the manufacturability of its installation is relatively poor, in case produce fold or mar in the installation, light-resistant layer probably wholly is scrapped.

Disclosure of Invention

To overcome at least one of the above-mentioned drawbacks, the present disclosure provides an α β meter, comprising: a guard including a first grid and a first positioning element; a light shielding member disposed adjacent to the shielding member, including a fixing member and at least one film layer mounted to the fixing member, the fixing member including a second grid and a second positioning element, and an orthographic projection of the first grid and the second grid in a direction in which the radiation is incident; and a seal positioning member including a fixing part engaged with the first positioning element and the second positioning element, the fixing part being arranged to fix the light shielding member and the shielding member in the α β meter.

In an embodiment of the present disclosure, the shapes of the first and second grids include a triangle, a quadrangle, a pentagon, and a hexagon.

In an embodiment of the disclosure, the first positioning element comprises at least one first recess, the second positioning element comprises at least one second recess, and the fixation part comprises at least two protrusions engaging with the first and second recesses, respectively.

In an embodiment of the disclosure, the position of the first notch relative to the first grid is the same as the position of the second notch relative to the second grid.

In an embodiment of the disclosure, the fixing member comprises a first fixing member engaged with the first positioning element and a second fixing member engaged with the second positioning element.

In an embodiment of the present disclosure, the first positioning element includes at least one hole, and the second positioning element includes at least one pin.

In an embodiment of the present disclosure, the position of the at least one hole relative to the first grid and the position of the at least one stud relative to the second grid are the same.

In an embodiment of the disclosure, the light shielding member includes two thin film layers, the two thin film layers are respectively located at two sides of the fixing member, and the thin film layers are aluminum-plated polyester films.

In an embodiment of the present disclosure, the protection element and the light shielding element are sheet-shaped structures.

In an embodiment of the disclosure, the α β measurement instrument further includes a housing, a scintillator, a photomultiplier tube, and a hardware module, wherein the light shielding member is located on a side of the scintillator away from the photomultiplier tube, the photomultiplier tube is located between the scintillator and the hardware module, and the housing accommodates therein the shielding member, the light shielding member, the sealing and positioning member, the scintillator, the photomultiplier tube, and the hardware module of the α β measurement instrument.

The alpha beta measuring instrument not only obviously improves the flatness of the light-proof piece to make the instrument beautiful, but also improves the strength of the light-proof piece and prevents the light-proof piece from deforming. In addition, the alpha beta measuring instrument obviously improves the installation process of the light-proof piece, improves the installation efficiency and success rate, and reduces the waste of time and materials. Furthermore, the measuring instrument according to the present disclosure not only can not increase the cost, but also can realize that no part is added compared with the prior art. Finally, the α β measurement instrument according to the present disclosure has a simple structure, and the layout of the original measurement instrument may not be changed.

Drawings

The present disclosure will become more fully understood from the detailed description and the accompanying drawings. The drawings illustrate one or more embodiments of the disclosure and, together with the written description, serve to explain the principles of the disclosure. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like elements of an embodiment, and wherein:

fig. 1 is a schematic cross-sectional view of an assembled shield, light shield and sealing spacer according to an exemplary embodiment of the present invention.

Fig. 2 is an exploded perspective view of a protection member, a light-shielding member including no film, and a sealing spacer according to an exemplary embodiment of the present invention.

Fig. 3 is a schematic view of a protective shield according to an exemplary embodiment of the invention.

Fig. 4 is a schematic structural view of a light-avoiding member according to an exemplary embodiment of the present invention.

Fig. 5 is an exploded perspective view of a shielding member, a light shielding member without a film, and a sealing spacer according to another exemplary embodiment of the present invention.

Fig. 6 is a partially enlarged cross-sectional schematic view of an α β meter according to an exemplary embodiment of the present invention.

Fig. 7 is a schematic view of an α β meter according to an exemplary embodiment of the present invention.

The correspondence of reference numerals to components is as follows: 1-guard, 2-fixture, 3-light-avoiding, 4-sealing fixture, 5-scintillator, 6-top cap, 7-photomultiplier, 8-housing, 9-hardware module, 10-bottom cap, 11-first grid, 12-first positioning element, 32-thin film layer, 21-second grid, 22-second positioning element, 40-fixing part, 41-first fixing part, 121-first notch, 221-second notch, 43-pin.

Detailed Description

The present disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Describing an embodiment of the present disclosure with reference to fig. 1 to 7, an α β measurement instrument in the present disclosure includes a protection member 1, a light-shielding member 3, and a sealing positioning member 4, wherein the protection member 1 includes a first grating 11 and a first positioning member 12, the light-shielding member 3 is disposed adjacent to the protection member 1, the light-shielding member 3 includes a fixing member 2 and at least one thin film layer 32 mounted on the fixing member 2, the fixing member 2 includes a second grating 21 and a second positioning member 22, the shape of the first grating 11 overlaps the shape of the second grating 21 in a direction in which a ray is incident, in other words, an orthographic projection of the first grating 11 and the second grating 21 in a direction in which a light is incident, and the sealing positioning member 4 includes a fixing member 40 mutually engaged with the first positioning member 12 and the second positioning member 22 for fixing the light-shielding member 3 and the protection member 1 in the α β measurement instrument.

The alpha beta measuring instrument in the disclosure can remarkably improve the flatness of the light shielding member 3, so that the instrument is more beautiful. Secondly, the α β measurement instrument of the present disclosure improves the strength of the light-shielding member 3, preventing deformation thereof. Moreover, the alpha beta measuring instrument can obviously improve the installation process of the light shielding part 3, improve the installation efficiency and success rate and reduce the waste of time and materials. In addition, the measuring instrument according to the present disclosure not only can not increase the cost, but also can realize that no part is added compared with the prior art. Finally, the α β measurement instrument according to the present disclosure has a simple structure, and the layout of the original measurement instrument may not be changed.

In an exemplary embodiment according to the present disclosure, the first grid 11 in the protective member 1 and the second grid 21 in the fixing member 2 of the light-shielding member 3 are the same in shape, in other words, orthographic projections of the first grid 11 and the second grid 21 in the light incident direction overlap, and may include a triangle, a quadrangle, a pentagon, a hexagon. Preferably, the first and second grids 11 and 21 may be honeycomb hexagonal grids, thereby improving flatness, strength, and manufacturability of the light-shielding member 3. When the shielding region of the hexagonal first grid 11 of the shielding member 1 completely coincides with the shielding region of the hexagonal second grid 21 of the light shielding member, the detection performance of the α β meter can be improved.

More specifically, the protection member 1 is mounted on the outer side of the light-shielding member 3 with a certain gap, for example, a gap of 2 to 3 mm, provided therebetween. This gap can be achieved, for example, by the sealing spacer 4, as shown in fig. 2, for example, by a ring of protrusions arranged in the middle of the inner circumference of the sealing spacer, which space the shield 1 from the light shield 3. When the protection member 1 is provided as a member with the honeycomb-shaped hexagonal grid, not only can the light shielding member be protected from being scratched by foreign objects, but also a high radiation transmittance can be achieved because the hexagonal grid of the protection member 1 can also achieve a transmittance of more than 85% at the normal incidence of the radiation because the area of the grid preventing the transmission of the α and β rays is small.

In an exemplary embodiment according to the present disclosure, the first positioning element 12 may include one or more first recesses 121, the second positioning element 22 may include one or more second recesses 221, and accordingly, the fixing member 40 may include one or more protrusions. Alternatively, the first positioning element may comprise one or more first protrusions and the second positioning element may comprise one or more second protrusions, and correspondingly, the fixation means may comprise one or more recesses. For example, as seen in fig. 2 to 4, the first and

second recesses

121 and 221 may include a semicircular shape, a rectangular shape, a polygonal shape, or the like. Accordingly, the shape of the protrusion corresponds to the shape of the first recess 121 and the second recess 221, so that the protection member 1 or the light shielding member 3 can be fixed into the sealing and positioning member 4.

The position of the first notch 121 with respect to the first grid 11 is the same as the position of the second notch 221 with respect to the second grid 21, so that it can be ensured that the orthographic projections of the first grid 11 of the shield member 1 and the second grid 21 in the light-shielding member 3 in the direction can completely overlap when viewed from the direction in which the radiation is incident. In particular, the notches of the first positioning element 12 may cross horizontally or vertically with respect to the central grid of the first grid 11, and likewise the notches of the second positioning element 22 cross horizontally or vertically with respect to the central grid of the second grid 21. For example, the first grid 11 may be configured as a honeycomb hexagon, and the notches of the first positioning element 12 may be configured as two, and as shown in fig. 3, a line connecting two notches may coincide with one of the hexagonal grids. Likewise, the second grid 21 may be configured as a honeycomb hexagon, and the two notches of the second positioning element 22 may also be configured as two notches, and the connecting line between two notches also coincides with one of the hexagonal grids. Or the recesses of the second positioning element may be provided in four, wherein a line between two recesses also coincides with one of the hexagonal grids and a line between two other recesses is perpendicular to the one of the hexagonal grids.

In an exemplary embodiment according to the present disclosure, as shown in fig. 2, the shape of the first recess 121 may be the same as the shape of the second recess 221, and the shape of the protrusion of the fixing member 40 matches the shape of the first recess 121 and the second recess 221, so that the shield member 1 and the light-shielding member 3 may be firmly fixed to the sealing and positioning member 4, while the first grid 11 of the shield member 1 and the second grid 21 of the fixing member 2 of the light-shielding member 3 may completely overlap, as viewed from the direction in which the radiation is incident, whereby it may be achieved that the transmittance of the radiation that is vertically incident is not substantially affected, and thus the overall detection efficiency of the α β meter is not affected.

In exemplary embodiments according to the present disclosure, the number and structure of the first and

second positioning elements

12 and 22 may be the same. In other embodiments, the number and configuration of the first positioning elements 12 and the second positioning elements 22 may not be the same.

In an exemplary embodiment according to the present disclosure, as shown in fig. 2, the fixing part 40 includes a first fixing part 41 and a second fixing part (not shown in the drawings) provided corresponding to the first fixing part 41. In other words, the first fixing part 41 and the second fixing part are disposed at opposite ends of the sealing spacer along the light path. The first fixing member 41 may be engaged with the first positioning element 12 to fix the protection member 1 into the sealing positioning member 4, and the second fixing member may be engaged with the second positioning element 22 to fix the light shielding member 3 into the sealing positioning member 4. Alternatively, the number of the first fixing parts and the number of the second fixing parts are each set to three, and the structure of one of the fixing parts is different from the other two, and correspondingly, the number of the first positioning elements 12 and the second positioning elements 22 engaged with the first fixing parts 41 and the second fixing parts, respectively, is also three, and the configuration of one of the positioning elements is different from the other two, whereby it can be more accurately ensured that the first grid 11 of the protection member 1 and the second grid 21 of the light-shielding member 3 can be completely overlapped when viewed from the direction in which the radiation is incident. Alternatively, a complete overlap of the first and second grids may be ensured by the different positions in which the first fixing part engaging with the first positioning element and the second fixing part engaging with the second positioning element are arranged.

In another exemplary embodiment according to the present disclosure, as shown in fig. 5, the first positioning element 12 and the second positioning element 22 may further comprise one or more holes, and the fixing part 40 comprises one or more pins 43, the shape of the pins matching the shape of the holes, so that when the protection member 1 is placed over the light-shielding member 3, the pins may be inserted into the corresponding holes, thereby ensuring the relative fixation between the protection member 1 and the light-shielding member 3. In fig. 5, the pins in the sealing and positioning element 4 corresponding to the holes of the light-shielding element 3 are not shown. Alternatively, the first positioning element may further comprise one or more pins and the second positioning element comprises one or more holes.

The first positioning element 12 may comprise a plurality of holes which are horizontally or vertically crossed with respect to the central grid of the first grid 11, and likewise the second positioning element 22 comprises a plurality of holes which are horizontally or vertically crossed with respect to the central grid of the second grid 21. For example, the first grid 11 may be configured as a honeycomb hexagon, the holes of the first positioning element 12 may be configured as four, and as shown in fig. 3, a first line between two holes may coincide with the grid of the hexagonal grid, and a second line between another two holes may be perpendicular to the first line. The second grid 21 can be provided as honeycomb hexagons and the studs of the second positioning element 22 can be provided as four, and similarly, the first line between two studs can coincide with the grid of the hexagonal grid and the second line between two other holes can also be perpendicular to the first line, so as to ensure that the holes are positioned in the same way with respect to the first grid 11 and the studs are positioned in the same way with respect to the second grid 21. Thereby, when the pins are inserted into the holes, a complete overlap of the first grid 11 and the second grid 21 can be accurately ensured.

In an exemplary embodiment according to the present disclosure, the light shield 3 includes the fixing member 2 and one or more thin film layers 32. Preferably, two film layers 32 are included, the two film layers 32 being respectively located at both sides of the fixing member 2, as shown in fig. 4, one film layer 32 is respectively provided at the upper side and the lower side of the fixing member 2, the film layers 32 may be bonded to the outer peripheral region of the fixing member 2 through the outer peripheral region, and the film layers 32 may be, for example, an aluminum-plated polyester film.

In an exemplary embodiment according to the present disclosure, the protective shield 1 and the light shield 3 are sheet-like structures. In other words, the protection member 1, the fixing member 2, and the film layer 32 are all layered or sheet-like structures, so that the protection member 1 and the light-shielding member 3 are in a laminated structure. For example, when the protection member 1 and the fixing member 2 are both in a honeycomb hexagonal grid, the middle area between the film layer 32 and the fixing member 2 can be more uniformly distributed by arranging the middle area of the grid, so that the flatness of the light shielding member 3 can be effectively improved, and the appearance of the instrument is beautiful; meanwhile, the strength of the light shielding piece 3 is improved, and the deformation of the measuring instrument is prevented; the mounting process of the light-shielding member 3 can also be greatly improved.

Now describing exemplary embodiments of the present disclosure in detail with reference to the drawings, as shown in fig. 1 to 7, an α β meter according to an exemplary embodiment of the present disclosure may include a housing 8, a top cover 6, a protection member 1, a light shielding member 3, a sealing spacer 4, a scintillator 5, a photomultiplier tube 7, a hardware module 9, a bottom cover 10, and the like. Wherein, the housing 8 can be a shielding case, the housing 8 can accommodate the above components of the α β measurement instrument together with the top cover 6, the top cover 6 is installed on the housing 8 and located outside the light-shielding part, the sealing positioning part 4 is located between the top cover 6 and the scintillator 5, the protection part 1 and the light-shielding part 3 can be made of stainless steel, the grid therein can be formed by electrochemical etching, the protection part 1 and the light-shielding part 3 can be located on one side of the scintillator 5 away from the photomultiplier tube 7, that is, the front side, the photomultiplier tube 7 is located between the scintillator 5 and the hardware module 9.

As shown in fig. 3, the protection member 1 is in a film shape, the periphery is in a ring shape, and the middle is in a honeycomb hexagonal grid, so that not only can the fixing member 2 in the light-shielding member be accurately positioned, but also the light-shielding member 3 can be protected, and the damage caused by scratching the film of the light-shielding member 3 by foreign objects in use can be avoided. For ease of positioning, both sides of the protection member 1 are provided with recesses, e.g. arc-shaped recesses.

As shown in fig. 2, the fixing member 2 is formed in a film shape, has a ring-shaped outer periphery and a honeycomb-shaped hexagonal grid in the middle, and is consistent with the shape, size and installation position of the protection member 1, so that the fixing member 1 can be accurately positioned, and grooves, such as arc-shaped grooves, identical to those of the protection member 1 are provided on both sides of the fixing member 2, so that the grids of the protection member 1 and the grids of the fixing member 2 of the light-shielding member 3 can be completely overlapped, thereby not affecting the transmittance of the vertical incidence of the radiation, and further not affecting the overall detection efficiency of the α β meter.

As shown in fig. 4, the light-shielding member 3 includes a film fixing member 2 and two aluminum-plated polyester films 32. The light shielding member 3 is installed at the front end of the plastic scintillator 5 to prevent the detection result from being influenced by the entrance of external light. Since the α -ray has extremely weak penetrating power, the light shielding member 3 may be generally formed of at least 2 layers of 2 to 5 μm thick aluminum-plated polyester film. The film fixing member 2 is adhered and fixed between the two layers of aluminized polyester films, and the groove at the periphery of the film layer is correspondingly trimmed according to the groove of the fixing member 2 so as to expose the groove at the periphery of the fixing member 2. Because the periphery of the fixing piece 2 is annular, and the middle part is a honeycomb hexagonal grid, the bonding area of the aluminized polyester film and the fixing piece 2 can be increased, the contact area of the fixing piece 2 and the middle part of the film can be increased, the contact parts are uniformly distributed, and the flatness, the strength and the installation manufacturability of the light-shading piece 3 can be effectively improved.

Referring to fig. 1-2 and 6-7, the sealing spacer 4 may be a silicone sealing sleeve, and a ring of spacer, such as a ring, may be disposed in the middle of the inner circumference of the sealing spacer 4, so that a space for accommodating the shielding member 1 is defined above the spacer, and a space for accommodating the light shielding member 3 is defined below the spacer, while the shielding member 1 and the light shielding member 3 are isolated. Above and below the silicone sealing boot are provided fixing parts 40 which can be engaged with the positioning element 12 of the protection member 1 and the positioning element 22 of the fixing member 2, i.e., a first fixing part 41 engaged with the first positioning element 11 and a second fixing part engaged with the second positioning element 22, such as one or more protrusions configured to match and engage with the groove of the protection member 1 and the groove of the fixing member 2, respectively, so that the protection member 1 and the light shield 3 can be securely mounted. Thereby, a complete overlapping of the honeycomb hexagonal grids of the shielding member 1 and the film fixing member 2 in the direction of normal incidence of the radiation can be achieved, thereby not affecting the transmittance of the normal incidence of the radiation and further not affecting the overall detection efficiency.

Referring to fig. 6, in addition, when the sealing and positioning member 4 is implemented as a silica gel sealing sleeve, the isolation of external light can be achieved at the same time, so that the accuracy of the measuring instrument is effectively guaranteed. Specifically, the plastic scintillator 5 is installed in an inner side groove below the silica gel sealing sleeve 4 and is tightly arranged with the light-shielding piece 3, and the top cover 6 and the shell 8 of the measuring instrument can be screwed or compressed, so that the silica gel sealing sleeve 4 is elastically extruded, and the light shielding of the measuring instrument is realized. When alpha and beta rays pass through the light shielding part 3 from the detection window and enter the plastic scintillator 5, ionization and excitation of scintillator atoms are caused, excited atoms excite scintillation photons with the wavelength positioned in visible light or close to the visible light, the scintillation photons strike the cathode of the photomultiplier tube 7 through light transmission processes of reflection, transmission and the like to generate photoelectrons, after multiplication, current signals are generated, and the current signals are finally processed and displayed through the hardware module 9, so that the detection of alpha and beta ray radiation is realized. Alternatively, the final detection result may be output via an external display device.

Hereinafter, describing an assembly process of the α β meter of the exemplary embodiment of the present disclosure, first, the photomultiplier tube 7 may be mounted to the upper end of the inner cavity of the meter housing 8; next, the plastic scintillator 5 is mounted above the photomultiplier tube 7; then, the light shielding part 3 is arranged below the silica gel sealing sleeve, and the protection part is arranged above the silica gel sealing sleeve; next, the whole silica gel sealing sleeve provided with the protection piece and the light-shielding piece 3 is arranged above the plastic scintillator 5, and then the top cover 6 is used for fixing firmly; finally, the hardware module 9 and the bottom cover 10 are installed.

The terminology used herein is for the purpose of exemplification of the disclosure only and should not be construed as limiting the meaning or scope of the disclosure. As used in this specification, the singular forms may include the plural forms unless the context clearly dictates otherwise. Furthermore, the terms "comprises" and/or "comprising," when used in this specification, do not specify the presence of stated shapes, integers, steps, acts, operations, elements, components, and/or groups thereof, nor preclude the presence or addition of one or more other different shapes, integers, steps, operations, elements, components, and/or groups thereof, or groups thereof. Spatially relative terms such as "above …", "above …", "above", "below …", "below …", "below …", "below" and the like are used herein for ease of description to describe the relationship of one element or feature to another element (element) or feature(s) as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation (e.g., packaging), in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as below, beneath or beneath other elements or features would then be oriented above or beneath the other elements or features. Thus, the exemplary term "above …" may include orientations of "above …" and "below …". It is to be understood that the relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

As used herein, terms such as "first," "second," and the like, are used to describe various components, assemblies, regions, layers and/or sections. It will be apparent, however, that no member, component, region, layer or section should be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section that will be described may also refer to a second element, component, region, layer or section without departing from the scope of the disclosure.

The foregoing description of the exemplary embodiments of the present disclosure has been presented for the purposes of illustration and description only and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to explain the principles of the disclosure and its practical application to enable others skilled in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present disclosure pertains without departing from its spirit and scope. Accordingly, the scope of the present disclosure is defined by the appended claims rather than by the foregoing description and the exemplary embodiments described therein.

Claims

1. An α β meter, comprising:

a guard including a first grid and a first positioning element;

the light shielding part is arranged adjacent to the protection part and comprises a fixing part and two film layers mounted on the fixing part, the two film layers are respectively positioned on two sides of the fixing part, the fixing part comprises a second grid and a second positioning element, and orthographic projections of the first grid and the second grid in the ray incidence direction are overlapped; and

a sealing positioner comprising a fixing component engaged with the first positioning element and the second positioning element, the fixing component being arranged to fix the light shielding member and the shielding member in the alpha beta meter,

wherein the first positioning element comprises at least one first recess, the second positioning element comprises at least one second recess, and the fixation part comprises at least two protrusions engaging with the first and second recesses, respectively.

2. The α β meter of claim 1, wherein the shape of said first and second grids comprises a triangle, a quadrilateral, a pentagon, a hexagon.

3. The α β meter of claim 1, wherein the position of said first notch relative to the first grid is the same as the position of said second notch relative to the second grid.

4. The α β meter of claim 1 or 3, wherein the fixation member comprises a first fixation member engaged with a first positioning element and a second fixation member engaged with a second positioning element.

5. The α β meter of claim 1, wherein said first positioning element comprises at least one hole and said second positioning element comprises at least one pin.

6. The α β meter of claim 5, wherein the position of said at least one hole relative to the first grid and the position of said at least one pin relative to the second grid are the same.

7. The α β meter according to claim 1, wherein the thin film layer is an aluminized polyester film.

8. The α β meter according to claim 1, wherein the shielding member and the light shielding member have a plate-like structure.

9. The α β meter according to claim 1, further comprising a housing, a scintillator, a photomultiplier tube, and a hardware module, wherein the light shielding member is located on a side of the scintillator remote from the photomultiplier tube, the photomultiplier tube is located between the scintillator and the hardware module, and the housing accommodates therein the shielding member, the light shielding member, the sealing and positioning member, the scintillator, the photomultiplier tube, and the hardware module of the α β meter.