Methods and devices for mounting a smoke detector with an optical measuring arrangement

Abstract

Device for mounting a smoke detector (1) with an optical measuring arrangement, in particular a scattered light measuring arrangement (2), comprising at least one light-emitting element (3) and at least one light-receiving element (4), which are mounted in or on a multi-part measuring chamber (5) comprising at least one upper measuring chamber part (6) and at least one lower measuring chamber part (7) with a labyrinth (8) forming a light-tight fluidic connection open to the outside atmosphere, wherein a positioning of the light-emitting element (3) and / or the scattered light-receiving element (4) in the scattered light measuring arrangement (2) is provided with respect to an optical axis (10) by simultaneously positioning and fixing the light-emitting element (3) and / or the light, in particular scattered light,The receiving element (4) is configured during the joining process of the multi-part measuring chamber (5) consisting of at least one upper measuring chamber part (6) and at least one lower measuring chamber part (7) to the optical axis (10) by means of at least one deformable element (11) and a holder (9). It is characterized in that the deformable element (11) is configured as a wedge-shaped body (12) in the upper measuring chamber part (6), which positions and fixes the light-emitting element (3) and / or the scattered light-receiving element (4) in the holder (9).

Description

[0001] The invention relates to a method and a device for mounting a smoke detector with an optical measuring arrangement, in particular a scattered light measuring arrangement, comprising at least one light-emitting element and at least one light-receiving element, in particular scattered light, which are mounted in or on a multi-part measuring chamber with a labyrinth that forms a light-tight fluidic connection open to the outside atmosphere.

[0002] Such methods and devices for constructing smoke detectors are described, among others, in DE 36 86 940 T2, JP 2006 - 267 128 A, US 4 584 485 A and DE 69 317 147 T2. In DE 69 317 147 T2, the description for Fig. 4, as also shown in US 4,584,485 A and JP 2006-267,128 A, how the individual components of a scattered light arrangement of a smoke detector are assembled. In this design of the scattered light arrangement, the light-emitting and light-receiving elements as well as the lenses and apertures are mounted in an optical component holder, which is then inserted into the measuring chamber. In DE 36 86 940 T2, the assembly of the individual components of a scattered light arrangement of a smoke detector is described using a base plate in which a light-emitting part and a light-receiving part with a measuring chamber between them are provided for smoke monitoring. The base plate has, as in Fig. 1 and Fig. Figure 2 shows a socket for each light-emitting element and a light-receiving element, which are fixed to the base plate via holders. This pre-assembled scattering light arrangement is then inserted and mounted in a measuring chamber.

[0003] The embodiments described above in the prior art for mounting the light-emitting and light-receiving elements in a scattering light arrangement have the disadvantages that this mounting of the scattering light arrangements is very complex and prone to errors due to the many different mounting steps.

[0004] Since the assembly of these conventional detectors is complex and time-consuming, this invention aims to create a device and a method that enables a more cost-effective, simplified, fast and safe assembly or manufacture of a smoke detector with an optical measuring arrangement, in particular a scattered light measuring arrangement.

[0005] This problem is solved by a device according to claim 1 and by a method according to claim 5.

[0006] Further advantageous embodiments of the device are specified in dependent claims 2-4.

[0007] Other advantageous embodiments of the method are specified in dependent claims 6 and 7. A smoke detector comprising a device according to the invention for mounting the smoke detector is specified in claim 8.

[0008] This problem is solved by the device according to the invention for mounting a smoke detector with an optical measuring arrangement, in particular a scattered light measuring arrangement, in that the light-emitting element and / or the light-receiving element, in particular scattered light, is positioned in the measuring arrangement to an optical axis, in that the simultaneous positioning and fastening of the light-emitting element and / or the scattered light receiving element during the joining process of the multi-part measuring chamber consisting of at least one upper measuring chamber part and at least one lower measuring chamber part to an optical axis is designed by means of at least one deformable element and a holder.Due to this inventive design of the deformable element for positioning and holding the light-emitting element and / or the light-receiving element on an optical axis of the measuring arrangement, simple and safe assembly is possible, so that, due to the deformable element, not only are corresponding tolerances and variations in the dimensions of the light-emitting element and / or the light-receiving element automatically compensated and automatic positioning and alignment of the light-emitting element and / or the light-receiving element is enabled in the joining process, but even incorrect positioning is prevented.

[0009] For this purpose, the deformable element is designed as a wedge-shaped body that positions and fixes the light-emitting element and / or the light-receiving element in the holder. Due to the wedge shape of the deformable element, the normal force acting upon it pushes the light-emitting element and / or the light-receiving element into the exact position in the holder via a corresponding horizontal and vertical movement, so that the axis of symmetry of the cylindrical light-emitting element (and, if applicable, the light-receiving element) coincides with an optical axis of the light measurement arrangement, in particular the scattered light measurement arrangement.

[0010] According to a suitable embodiment of the device according to the invention, the deformable element has at least a partial deformation zone which undergoes plastic deformation when the material's yield strength is exceeded during the joining process of the multi-part measuring chamber. This deformation zone absorbs the joining forces or movement during the joining process of the lower and upper parts of the measuring chamber that exceed the requirements for the precise positioning of the light-emitting element and / or the scattered light-receiving element. Component tolerances are compensated for by the deformation zone, and the light-emitting element and / or the light-receiving element are fixed within this zone by the material deformation.

[0011] In a further advantageous embodiment of the device according to the invention, the holder is configured with at least one stop holder, at least one chamfered element, and at least one radial snap element. During the joining process of the measuring chamber lower part to the measuring chamber upper part, the light-emitting element and / or the light-receiving element is pushed into the holder by a vertical and horizontal movement caused by the wedge-shaped element of the deformable element. The radial snap element receives the cylindrical bodies of the light-emitting element and / or the light-receiving element and positions their axis of symmetry on an optical axis of the light measuring arrangement, in particular a scattered light measuring arrangement.The chamfer element also has a partially wedge-shaped structure so that the light-emitting element and / or the light-receiving element do not tilt and are pushed uniformly over the chamfer element and the wedge-shaped body of the deformable element towards the stop bracket.

[0012] In a highly advantageous embodiment of the device according to the invention, a snap-fit ​​connection is provided on a measuring chamber upper part and / or a measuring chamber lower part of the multi-part measuring chamber. Due to this snap-fit ​​connection, only a vertical movement between the measuring chamber upper and lower parts is possible during the joining process of the multi-part measuring chamber. The measuring chamber lower part and the measuring chamber upper part are connected to each other via the snap-fit ​​connection in the final position of the joining process. This snap-fit ​​connection has a further function during the joining process: it ensures that the measuring chamber lower part can only be moved relative to the measuring chamber upper part by means of a vertical movement, and that they come into precise contact at the intended joint points.

[0013] Furthermore, the problem is solved by a method according to the invention for constructing a smoke detector with a light measuring arrangement, in particular a scattered light measuring arrangement, in that at least one light-emitting element and / or at least one light-receiving element, in particular a scattered light-receiving element, is inserted into or onto a multi-part measuring chamber consisting of at least one upper measuring chamber part and at least one lower measuring chamber part, wherein in the joining process of the upper measuring chamber part and the lower measuring chamber part the light-emitting element and / or at least the light-receiving element, in particular a scattered light-receiving element, is automatically aligned and positioned on the optical axis by means of at least one deformable element and a holder.

[0014] For this purpose, the light-emitting element and / or the light-receiving element, in particular scattered light, is inserted into the holder, positioned and fixed by means of a wedge-shaped body as a deformable element.

[0015] According to a very practical design of the process, the deformable element with a partial deformation area is plastically deformed when a yield strength of the material is exceeded during the joining process of the multi-part measuring chamber.

[0016] In an advantageous further development of the method, the measuring chamber lower part is positioned relative to the measuring chamber upper part via a sliding rail area of ​​the locking lug fastening, so that a precise alignment is always provided in the joining process of the measuring chamber lower part to the measuring chamber upper part.

[0017] The invention allows for numerous embodiments. Some of these will be briefly explained here with reference to the following figures. Identical elements in the figures are designated with the same reference numerals. Fig. Figure 1 shows a smoke control system with smoke detectors, Fig. Figure 2 shows a sectional view of an embodiment of a smoke detector with a scattering light arrangement of the door lintel smoke detector made of Fig. 1 based on the intersection line AB, Fig. Figure 3 shows a three-dimensional view of an embodiment of the measuring chamber upper part of the device according to the invention. Fig. Figure 4 shows a three-dimensional view of an embodiment of a measuring chamber lower part of the device according to the invention. Fig. Figure 5 shows an isolated, enlarged, three-dimensional view of the holder made from the lower part of the measuring chamber of an embodiment of the device according to the invention. Fig. 4, Fig. Figure 6 shows a first schematic sectional view of an embodiment of the device according to the invention at the beginning of the joining process, Fig. Figure 7 shows a second schematic sectional view of an embodiment of the device according to the invention in the middle of the joining process, and Fig. Figure 8 shows a third schematic sectional view of an embodiment of the device according to the invention at the end of the joining process.

[0018] In Fig. Figure 1 shows an embodiment of an application of the smoke detector 1 according to the invention with a scattered light measuring arrangement 2 in a hold-open system. In this application, the smoke detectors 1 are mounted on the door lintel and on the ceiling on both sides of the room enclosure or door, and optionally connected to a smoke control unit 26.

[0019] The term "hold-open system" refers to devices or combinations of devices designed to disable the function of closing mechanisms in a controlled manner. When the associated release mechanism is activated in the event of a fire or other triggering event, open room closures or doors are automatically closed by the closing mechanism. A hold-open system consists, for example, of at least one fire alarm, smoke detector, or smoke switch 1, a release mechanism, a hold-open device 27 (such as a door closing mechanism, anchor plate, and door holding magnets), a power supply, and optionally a release button (e.g., a manual push button 28) and a control unit 26. Hold-open systems are suitable for movable room closures, such as fire doors, smoke control doors, and other closures that must be self-closing.In the event of a fire, these self-closing, movable room partitions separate the room areas in a building from each other for fire protection reasons, by means that in the event of a fire the smoke detector 1 detects smoke, the locking device 27 is automatically triggered and the room partition is automatically closed.

[0020] In the Fig. Figure 2 is a sectional view of an embodiment of a smoke detector 1 with a scattering light arrangement 2 of the door lintel smoke detector 1. Fig. 1 shown using section line AB. This optical smoke detector 1 operates on the scattered light principle using the scattered light measuring arrangement 2. This embodiment of a measuring chamber of a door lintel smoke detector in the Fig. Figures 2 to 8 are only examples, as the inventive design for the exact mounting of the light emitter 3 and / or the light receiver 4 in the multi-part measuring chamber housing 5 can be used in any type of optical smoke detector 1, smoke alarm, or smoke warning device, or even in point-type extinction smoke detectors. The light emitter, or light-emitting element 3, and the light receiver, or scattered light-receiving element 4, are arranged in the multi-part measuring chamber 5 such that the emitted light beam does not directly strike the light receiver 4 along the optical axis 10 of the light emitter 3. For this purpose, several apertures 22 are provided, which limit the emission characteristics or the light beam of the light emitter 3. Only the light scattered by suspended particles, such as soot particles, according to the Tyndall effect, is scattered towards the light receiver 4 and is converted by the light receiver or photodiode 4 into a proportional electrical measurement signal.This measurement signal is processed and evaluated by evaluation electronics, for example by determining whether a limit value of a parameter of the measurement signal has been exceeded and consequently triggering a corresponding optical and / or acoustic signaling or alarm on site as well as communication of the alarm status to a remote alarm center.

[0021] The scattered light detector operates with a light transmitter or light-emitting element 3 and a light receiver, e.g., a photodiode or a scattered light-receiving element 4, which are located in a measuring chamber 5 protected from ambient light, larger foreign objects, and insects. This measuring chamber 5 is multi-part so that the additional components, such as the light transmitter or light-emitting element 3 and the light receiver or scattered light-receiving element 4, as well as lenses and apertures 22, can be positioned and mounted within the multi-part measuring chamber 5. The light transmitter 3 emits light radiation with a specific radiant power and predetermined wavelengths into the measuring chamber 5.

[0022] This light radiation emitted by light source 3 is in Fig. 2 is symbolized by an arrow along the optical axis 10. The rotationally symmetrical, cone-shaped radiation characteristics of the light emission from the light source 3, such as from a light-emitting diode (LED) or infrared LED, are not explicitly shown in this diagram but are schematically characterized by an arrow indicating the main direction of emission. The light emission strikes the wall of the measuring chamber 5 and is largely absorbed there. However, a small portion of the emission is diffusely reflected at the surface and thus also reaches the light receiver 4, which has no direct line of sight to the light source 3 and / or a direct beam path from the light source 3 to the light receiver 4 is prevented by apertures 22. The resulting measurement signal at the light receiver 4 is called the background signal. It can be used, for example, for functional monitoring. If smoke now enters, e.g., Fig. When light enters measuring chamber 5, symbolized by a small cloud with circular soot particles (2), some of the radiation is reflected, diffracted, and refracted by the smoke or soot particles. This scattering, refraction, or diffraction of the light beam by the particles is described in Fig. 2 is symbolically indicated by the smaller star-shaped light radiation arrows. Thus, this scattered light of the light beam increases the irradiance at the light receiver 4. Depending on the sensitivity of the light receiver 4 or the photodiode, the received radiant power is converted into a current, which is measured and evaluated in modern fire alarms or smoke detectors 1 by a microcontroller. In such measurement setups of a scattered light measurement arrangement, it is important that the optical components, such as light emitters, light receivers, lenses, and apertures, are positioned and fixed precisely relative to each other on an optical axis 10 or on several optical axes 10 arranged in specific ratios to each other. Fig. In Figure 2, the optical axes 10 of the light source 3 and the light receiver 4 are arranged, for example, at a 90° angle to each other. However, for evaluation purposes, any angles, including multiple angles, between one or more light sources 3 and one or more light receivers 4 can be used, from which different information about the measurement situation can be determined. By comparing the measurement signals from scattered light measurement paths with different angles of the optical axes and / or different wavelengths of the emitted light from the light source 3, further information about particle size, particle type, and type of fire can be determined. Thus, for example, it is possible to differentiate between dust, water vapor, and cigarette smoke particles and soot particles from different fires.

[0023] In Fig. Figure 3 shows a three-dimensional view of an embodiment of the measuring chamber upper part 6 of the device according to the invention. The cup-shaped structure of the measuring chamber upper part 6 can be roughly divided into two sub-areas. For example, in this embodiment, into a first sub-area with measuring chamber area 29 bounded by the labyrinth 8 and the lid, and a second sub-area, the mounting area 30, with the elements positioning and fixing the light-emitting element 3, consisting of a stop-mount 17, a wedge-shaped, deformable element 11, 12, and several apertures 22, which are partially semicircular in the measuring chamber upper part 6. The deformable element 11 is designed as a wedge-shaped body 12 with at least a partial deformation area 13. In this embodiment, the deformation area 13 is formed by a reduction in the material thickness or...The thickness of the wedge-shaped body 12 is designed so that plastic deformation occurs due to the higher flow properties of the material by means of the higher force acting on a smaller effective area, because of the reduced material thickness in this deformation zone 13. By reducing the material thickness of the wedge-shaped body 12, a target deformation zone 13 for plastic deformation at a specific mechanical force on this effective area of ​​the wedge-shaped body 12 is thus defined. The labyrinth 8 is formed by interlocking triangular structures so that no extraneous light or ambient light can penetrate into the measuring chamber 5 from the outside, but the smoke or the measuring fluid can penetrate into the measuring chamber 5 almost unhindered. The device according to the invention with a measuring chamber 5 includes further structures for an ambient light-blocking labyrinth 8, which are not explicitly shown here.A locking lug fastening is provided to secure the upper part of the measuring chamber 6 to the lower part of the measuring chamber 7; these lugs interlock.

[0024] In Fig. Figure 4 shows a three-dimensional view of an embodiment of the measuring chamber lower part 7 of the device according to the invention. The base-shaped structure of the measuring chamber lower part 7 forms the precisely fitting counterpart to the measuring chamber upper part 6. In the edge region of the base surface bounding the measuring chamber area 29, corresponding base elements of the labyrinth structures 8 are designed, which precisely join with the labyrinth structures 8 of the measuring chamber upper part 6 via attachment structures. In the measuring chamber area 29, a semicircular arc-shaped transmitting light aperture 22 and a scattering light receiving aperture 21 are formed in the base surface, so that the cone-shaped light radiation of the light source 3 along the optical axis 10 does not fall directly onto the light receiver located below the scattering light receiving aperture in a right-angled arrangement to the optical axis 10.This reduces the background signal and thus prevents overloading of the light receiver 4, ensuring that the measurement signal does not exceed the maximum detection limit. A bracket 9 for positioning and fixing the light transmitter 3 is provided in the mounting area 30. This bracket 9 is located in . Fig. Figure 5 is enlarged and shown isolated from the measuring chamber base 7. The holder 9 consists of at least one radial snap-in element 19, a stop bracket 17, a chamfer element 18, and two radial apertures 22, which are at least partially formed as semicircles or semicircular arcs in the base. Furthermore, the measuring chamber base 7 has two feedthroughs 23 for inserting and passing through the two connecting wires 24 of the light transmitter 3. The radial snap-in element 19 positions and fixes the cylindrical base body with the lens-shaped head end of the LED or light transmitter 3 on the optical axis 10 and encompasses it at least partially radially. The collar area of ​​the stop bracket 17 rests against the cylindrical base body of the LED or light transmitter 3, ensuring that the LED chip and the lens-shaped head end of the LED or light transmitter 3 are always positioned at the same location along the optical axis 10. An inexact orIncorrect positioning of the LED chip in the holder 9, instead of the intended position on the optical axis 10, affects the background signal in such a way that, due to overload of the receiver by the background signal, a usable measurement signal can no longer be determined. Incorrect positioning can also cause the main emission characteristic of the light source 3 to deviate from the ideal optical axis 10 or vary the light power of the light source 3 emitted into the measuring chamber 5. Precise positioning using the deformable element and the holder counteracts this. This is achieved by means of the snap-fit ​​fastening 20. Fig. 3 & 4 the positioning and alignment of the measuring chamber upper part 6 to the measuring chamber lower part 7 during the joining process with a joining movement 25 is specified by corresponding slide rails and the snap hooks engage in corresponding snap grooves or recesses in the end position of the joining process of the measuring chamber upper part 6 and the measuring chamber lower part 7.

[0025] In the Fig. Figures 6 to 8 show the first, second, and third schematic sectional views of an embodiment of the device according to the invention at the beginning, middle, and end of the joining process. Fig. In this first schematic sectional view of an embodiment of the device or process step according to the invention, the measuring chamber upper part 6 is arranged in its starting joining position relative to the measuring chamber lower part 7, so that the snap-in fastener 20 is guided by corresponding slide rails during the joining movement 25. The LED or light transmitter 3 is either manually inserted into the radial snap element 19, so that the connecting wires 24 protrude through the openings 23 in the base of the measuring chamber lower part 7, or the LED or light transmitter 3 is placed on the radial snap element 19 in a corresponding position. Fig. Figure 7 shows a second schematic sectional view of an embodiment of the device or a process step according to the invention, which shows the upper measuring chamber part 6 and the lower measuring chamber part 7 in their alignment joining position. In this alignment joining position, the chamfered element 18 in the lower measuring chamber part 7, together with the wedge-shaped body 12 of the deformable element 11, acts on the end part of the light emitter or the LED 3 with opposing horizontal forces 15 and vertical forces 16, so that the light emitter or the LED 3 is aligned accordingly in the holder 9. The collar area or thickened area of ​​the LED or the light emitter 3 is pushed or guided by the chamfered element 18 and the wedge-shaped element 12 against the two stop brackets 17 in the upper measuring chamber part 6 and the lower measuring chamber part 7 by the horizontal movement or the horizontal force 15. Due to the vertical force 15, the collar area or thickened area of ​​the LED or the light emitter 3 is pressed against the two stop brackets 17 in the upper measuring chamber part 6 and the lower measuring chamber part 7 by the horizontal movement or the horizontal force 15.During the vertical movement 16, the light sensor or LED 3 is pushed into the radial snap element 19 and positioned on the optical axis 10. This horizontal movement or horizontal force 15 and this vertical force or vertical movement 16 are caused by the joining movement or joining force 25 of the upper measuring chamber part 6 and lower measuring chamber part 7 and by a normal force of the chamfer element 18 and the wedge-shaped element 12 on the collar area of ​​the light transmitter or LED 3.

[0026] If the light emitter or LED 3 is in its final position on the optical axis 10, as shown in Fig.As shown in Figure 8, a continuing joining force 25 until the locking lug 20 engages between the lower measuring chamber part 7 and the upper measuring chamber part 6 causes the deformation zone 13 of the wedge-shaped element 12 to deform plastically. This plastic deformation occurs due to the additional force acting on a reduced effective area of ​​the wedge-shaped element 12, causing it to deform irreversibly after exceeding the yield strength of the material in the deformation zone 13, and this deformation is retained in the future. This deformation zone allows manufacturing tolerances of the optical housing of the LED or the light source 3 to be compensated for, ensuring secure fixation. Furthermore, precise positioning of the LED or light source 3 and / or, if applicable, the photodiode or light receiver 4 is guaranteed, as these elements 3, 4 are pushed into their final position in the holder 9 and fixed.

[0027] Positioning takes place during the joining process. Deforming a thin plastic rib or the deformation area 13 on the wedge-shaped element 12 in the upper part of the measuring chamber 6 offers the advantage that each light emitter or IR LED 3 is individually slid into the correct position within its large tolerance range in the respective assembly or holder 9 and held there. The multi-part measuring chamber 5 is generally not opened again after the joining process. This device and method according to the invention enable reliable, simplified positioning of the light emitter 3 and / or the light receiver 4 during the joining process of the upper part of the measuring chamber 6 with the lower part of the measuring chamber 7, compensating for component tolerances. Reference symbol list 1 smoke detector 2 Scattered light measurement setup 3 light-emitting elements, LEDs, light transmitters 4 Scattered light receiving element, photodiode, light receiver 5 multi-part measuring chambers 6 Measuring chamber top 7 Measuring chamber lower part 8 Labyrinth 9 bracket 10 optical axis 11 elastically deformable element 12 wedge-shaped bodies 13 Deformation range 14 plastic deformation 15 Horizontal movement, horizontal force 16 Vertical movement, vertical force 17 Stop bracket 18 phase element 19 Radial snap-in element 20 Latch Fastening 21 Stray light reception aperture 22 Transmission lens hood 23 Implementation 24 connecting wire 25 Joining movement, joining force 26 Smoke control center, central unit 27 Door magnet locking device, door closing mechanism 28 trip switches 29 Measuring room area 30 Mounting area

Claims

[1] Device for mounting a smoke detector (1) with an optical measuring arrangement, in particular a scattered light measuring arrangement (2), comprising at least one light-emitting element (3) and at least one light-receiving element (4), which are mounted in or on a multi-part measuring chamber (5) comprising at least one upper measuring chamber part (6) and at least one lower measuring chamber part (7) with a labyrinth (8) forming a light-tight fluidic connection open to the outside atmosphere, wherein a positioning of the light-emitting element (3) and / or the scattered light-receiving element (4) in the scattered light measuring arrangement (2) is provided with respect to an optical axis (10) by simultaneously positioning and fixing the light-emitting element (3) and / or the light, in particular scattered light,The receiving element (4) is designed in the joining process of the multi-part measuring chamber (5) consisting of at least one measuring chamber upper part (6) and at least one measuring chamber lower part (7) to the optical axis (10) by means of at least one deformable element (11) and a holder (9). characterized by , that the deformable element (11) is designed as a wedge-shaped body (12) in the upper part of the measuring chamber (6), which positions and fixes the light-emitting element (3) and / or the scattered light-receiving element (4) in the holder (9). [2] Device for mounting a smoke detector (1) according to claim 1, characterized by , that the deformable element (11) has at least partially a deformation area (13) which, when a yield strength of the material is exceeded during the joining process of the multi-part measuring chamber (5), forms a plastic deformation (14). [3] Device for mounting a smoke detector (1) according to one or more of the preceding claims, characterized by , that the holder (9) is designed from at least one stop holder (17), at least one chamfer element (18) and at least one radial snap element (19). [4] Device for mounting a smoke detector (1) according to one or more of the preceding claims, characterized by , that a locking lug attachment (20) is provided on a measuring chamber upper part (6) and / or a measuring chamber lower part (7) of the multi-part measuring chamber (5) and that due to this locking lug attachment (20) only a vertical movement (16) between the measuring chamber upper part (6) and measuring chamber lower part (7) is designed during the joining process of the multi-part measuring chamber (5). [5] Method for constructing a smoke detector (1) with an optical measuring arrangement, in particular a scattered light measuring arrangement (2), by placing at least one light-emitting element (3) and / or at least one light-receiving element (4) in or on a multi-part measuring chamber (5) consisting of at least one upper part of the measuring chamber (6) and at least one lower part of the measuring chamber (7), that in the joining process of the measuring chamber upper part (6) and the measuring chamber lower part (7) the light-emitting element (3) and / or at least the light, in particular scattered light, receiving element (4) is automatically aligned and positioned on the optical axis (10) by aligning and fixing the light-emitting element (3) and / or at least the scattered light receiving element (4) by means of at least one deformable element (11) and a holder (9). characterized by , that the light-emitting element (3) and / or the scattered light receiving element (4) is pushed, positioned and fixed in the holder (9) by means of a wedge-shaped body (12) in the upper part of the measuring chamber (6) as a deformable element (11). [6] Method for constructing a smoke detector (1) according to claim 5, characterized by , that the deformable element (11) with a partial deformation area (13) is plastically deformed when a yield strength of the material is exceeded during the joining process of the multi-part measuring chamber (5). [7] Method for constructing a smoke detector (1) according to at least one of the preceding claims, characterized by , that the measuring chamber lower part (7) is positioned to the measuring chamber upper part (6) via a sliding rail area of ​​the locking lug fastening (20), so that in the joining process of the measuring chamber lower part (7) to the measuring chamber upper part (6) a precise alignment to each other is always provided. [8] Smoke detector (1), comprising an optical measuring arrangement, in particular a scattered light measuring arrangement (2), comprising at least one light-emitting element (3) and at least one light-receiving element (4), which are mounted in or on a multi-part measuring chamber (5) with a labyrinth (8) which forms a light-tight fluidic connection open to the outside atmosphere, characterized by that it has a device for mounting the smoke detector (1) according to one or more of claims 1 to 4.

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