CN217385114U

CN217385114U - Scattered light collecting and measuring assembly

Info

Publication number: CN217385114U
Application number: CN202221167802.8U
Authority: CN
Inventors: 王少永; 惠旅锋
Original assignee: Sothis Suzhou Environment Technology Co ltd
Current assignee: Sothis Suzhou Environment Technology Co ltd
Priority date: 2022-05-16
Filing date: 2022-05-16
Publication date: 2022-09-06
Anticipated expiration: 2032-05-16

Abstract

The utility model provides a scattered light collection measurement element is applied to among the particle count sensor, the particle count sensor includes photosensitive area, gas circuit subassembly and photoelectric detector, the photosensitive area is formed by the light source emission beam of particle count sensor, scattered light collection measurement element includes total reflection light collector and the photoelectric detector who combines the setting with total reflection light collector, total reflection light collector surrounds photosensitive area setting, total reflection light collector is inside to have the plane of reflection, the plane of reflection is around forming the reflection chamber, and total reflection light collector is last to have a plurality of openings; the light beam traverses the total reflection light collector through the two openings, the air path assembly conveys air flow in the reflection cavity through the two openings, and the light detection surface of the photoelectric detector is exposed to the reflection cavity through one opening. By adopting the scattered light collecting and measuring assembly, the scattered light receiving quantity of the photoelectric detector can be ensured, the interference of stray light is reduced, and the detection precision of the particle counting sensor is effectively improved.

Description

Scattered light collecting and measuring assembly

Technical Field

The utility model relates to a particle count sensor correlation technique field, more accurate say so and relate to a scattered light collection measurement element.

Background

The particle counting sensor outputs a uniform light field through an optical assembly of the particle counting sensor, the air flow to be detected is conveyed through the air path assembly to penetrate through the light field to form a photosensitive area, particles in the air flow to be detected emit scattered light after being irradiated in the photosensitive area, the scattered light is converted into photocurrent after being received by a photoelectric detector arranged on the side portion of the photosensitive area, the photocurrent is converted into a voltage pulse signal through an amplification processing circuit, and then the number and the particle size of the particles can be judged according to the voltage pulse signal. The more scattered light that is received by the photodetector, the higher the accuracy of the particle resolution. The photodetectors in existing particle counting sensors can only receive scattered light projected in the direction in which they are located. In order to improve the measurement accuracy of the particle counting sensor, it is necessary to make the photodetector receive more scattered light. In the conventional solution, a hemispherical mirror is generally disposed on a side of the photosensitive region opposite to the photodetector, and reflected light is collected by the plate spherical mirror and reflected to the photodetector. In the existing scheme, a large amount of scattered light cannot be collected, and due to the divergence angle of laser, even if a light beam is shaped, stray light influencing the accurate counting and particle distinguishing of a particle counter inevitably exists in the light beam propagation process, and the stray light influences the particle size distinguishing and the accurate counting of the particles after being received by a photoelectric detector.

In summary, there is a need in the art for an improved structure for collecting scattered light from particles in a particle counting sensor, so that the photodetector can receive more scattered light, and the influence of the stray light on the photodetector is reduced, so as to improve the detection accuracy of the particle counting sensor.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model aims to provide a measuring component is collected to scattered light, including total reflection light collector and photoelectric detector, total reflection light collector surrounds photosensitive area setting, has the opening that supplies the light beam to pass, installs the opening of gas circuit subassembly and sets up photoelectric detector's opening, and the particle scattered light of photosensitive area reachs photoelectric detector's light sensing face after the reflection in total reflection light collector to increase photoelectric detector's scattered light acceptance, prevent simultaneously that total reflection light collector afterbody stray light from reacing photoelectric detector's light sensing face.

In order to achieve the above object, the present invention provides a scattered light collecting and measuring assembly, which is applied to a particle counting sensor, the particle counting sensor comprises a housing, a light path assembly combined with the housing for emitting and recovering light beams, a gas path assembly for circulating gas flow to be measured containing particles, and a scattered light collecting and measuring assembly; the light beam and the airflow overlapping area form a photosensitive area, particles are scattered in the photosensitive area to form scattered light, the scattered light collecting and measuring component comprises a total reflection light collector and a photoelectric detector combined with the total reflection light collector, the total reflection light collector surrounds the photosensitive area, a reflecting surface is arranged inside the total reflection light collector and used for collecting the scattered light and guiding the scattered light to the photoelectric detector, the reflecting surface surrounds the photosensitive area to form a reflecting cavity, a plurality of openings correspondingly used for light beam propagation, airflow circulation and photoelectric detector installation are formed in the total reflection light collector, and light beams and airflow passing through the openings are not in contact with the periphery of the openings.

Preferably, the plurality of openings include coaxial light inlet and light outlet for light beam propagation, the light beam entering the reflective cavity through the light inlet and exiting the reflective cavity through the light outlet.

Preferably, the plurality of openings include a detection port, the photodetector is disposed in combination with the reflective cavity through the detection port, and the reflective surface regions are provided as gaps between the detection port and the remaining plurality of openings.

Preferably, the plurality of openings include a coaxial air inlet and a coaxial air outlet for air flow circulation, and the air path assembly is combined with the total reflection light collecting body through the air inlet and the air outlet.

Preferably, the axes of the light inlet and the light outlet are coplanar with the axes of the air inlet and the air outlet.

Preferably, the housing has a passage through which the light beam propagates, the passage, the light inlet and the light outlet being coaxial.

Preferably, the reflective surface is a smooth concave surface facing the photodetector region.

Preferably, the light reflectivity of the reflecting surface is more than or equal to 99%.

Preferably, the total reflection light collector body is provided with an outer surface at the outside, and at least partial area of the outer surface is a light absorption surface.

Compared with the prior art, the utility model discloses a measuring component is collected to scattered light's advantage lies in: by adopting the scattered light collecting and measuring component, almost all the particle scattered light of the photosensitive area can be directly or indirectly received by the photoelectric detector, so that the scattered light receiving quantity of the photoelectric detector can be ensured, and the detection precision of the particle counting sensor is effectively improved; the scattered light collecting and measuring assembly can effectively prevent stray light from entering the interior of the scattered light collecting and measuring assembly, reduce the probability of introducing the stray light into particle scattered light, and improve the detection precision of the particle counting sensor.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a scattered light collecting and measuring assembly of the present invention disposed in a particle counting sensor.

FIG. 2 is a schematic view of the structure of the gas path assembly of the particle counting sensor and the scattered light collection and measurement assembly

Fig. 3 is a cross-sectional view of the total reflection light collector.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1 and fig. 2, a scattered light collecting and measuring assembly according to the present application is applied to a particle counting sensor, the particle counting sensor includes a housing (not shown), an optical path assembly combined with the housing for emitting and recovering light beams, an air path assembly combined with the housing for circulating a gas flow containing particles to be measured, and a scattered light collecting and measuring assembly combined with the housing; the light beam and the air current overlap region form a photosensitive region, particles are scattered in the photosensitive region to form scattered light, the light path component comprises a light source 1, a light shaping component 2, a light trap 4 and an air path component which are sequentially arranged, the air path component comprises an air inlet piece 71 and an air exhaust piece 72, the air current 70 to be detected containing the particles flows through the air inlet piece 71 and the air exhaust piece 72 to form an air path, the light source 1 emits a light beam 10, the light beam 10 crosses the air path after passing through the light shaping component 2 to form a photosensitive region 3, and the light beam 10 reaches the light trap 4 after passing through the photosensitive region 3 to be received by the light trap. I.e. the particle counting sensor comprises a light sensitive area 3, which light sensitive area 3 is formed by a light beam 10 emitted by a light source 1. The air inlet part 71 is provided with an air inlet 711 facing the photosensitive area 3, the air outlet part 72 is provided with an air outlet 721 facing the photosensitive area 3, the air inlet 711 and the air outlet 721 are respectively positioned on two sides of the photosensitive area 3 and are oppositely arranged on a propagation path of the non-light beam 21, the gas flow 70 to be measured flows to the air outlet 721 through the air inlet 711, the light beam 10 and the gas flow 70 to be measured are mutually perpendicular to each other to meet, and particles in the gas flow 70 to be measured interact with light in the photosensitive area 3 to emit scattered light.

The light shaping assembly 2 is used for realizing collimation, compression and focusing of the light beam 10, and the light shaping assembly comprises one or more of a spherical mirror, an aspherical mirror and a cylindrical mirror, and can further comprise size limiting structures such as a diaphragm and a through hole for limiting the cross section size of the light beam, and the specific limitation is not provided herein. The light beam 10 shaped by the light shaping component 2 passes through the photosensitive region 3 on the propagation path and then reaches the optical trap 4 to be received by the optical trap, the total reflection light collector 5 does not influence the propagation path of the light beam 10, and the total reflection light collector 5 does not influence the flow path of the gas flow 70 to be measured.

As can be seen from fig. 3, the scattered light collecting and measuring assembly includes a total reflection light collector 5 and a photodetector 6 combined with the total reflection light collector, the total reflection light collector 5 is disposed to surround the photosensitive region 3, the total reflection light collector 5 has a reflective surface therein for collecting scattered light and guiding the scattered light to the photodetector, the reflective surface surrounds the photosensitive region to form a reflective cavity 50, i.e. a reflective cavity 50 as a space, a wall of the space is a reflective surface, the total reflection light collector 5 has a plurality of openings corresponding to light beam propagation, air flow circulation and photodetector installation, the light beam and air flow passing through the openings are not in contact with the periphery of the corresponding openings, the photosensitive region 5 is located in the reflective cavity 50, the light beam 10 passes through the total reflection light collector 5 through two openings of the plurality of openings, the air path assembly delivers the air flow inside the reflective cavity 50 through two openings of the plurality of openings, here, the non-contact of the light beam and the gas flow with the periphery of the corresponding opening means that the periphery of the cross section of the light beam and the cross section of the gas flow is not in contact with the periphery of the opening in a measurable sense, and does not include a very small amount of scattered light and the like, and it is preferable that the periphery of the light beam and the gas flow passing through the opening is close to and not in contact with the periphery of the corresponding opening, and the light receiving surface of the photodetector 6 is exposed to the reflective cavity 50 through one opening. Part of scattered light 11 generated by the photosensitive region 3 is directly received by the light receiving surface of the photodetector 6, and part of scattered light 12 is received by the light receiving surface of the photodetector 6 after being reflected once or more in the reflective cavity 50. Preferably, the light reflectance of the reflecting surface is not less than 99%. The reflecting surface can be obtained by a reflecting mirror or a reflecting coating, and the photodetector is selected from a photodiode, a photomultiplier tube, and the like for converting light into electricity, which is not limited specifically herein.

By providing the total reflection light collector 5, most of the scattered light generated from the photosensitive region 5 is received by the light receiving surface of the photodetector 6. In addition, due to the characteristic of the speed of light, the multiple reflections do not influence the time for the photoelectric detector to acquire the signal of the scattered light of the same particle. The total reflection light collector 5 can also prevent external stray light from entering the interior of the reflection cavity 50, and reduce the probability of introducing the stray light into particle scattering light.

Specifically, the plurality of openings include a coaxial light inlet 51 and a light outlet 52 for light beam propagation, and the light beam 10 enters the reflective cavity 50 through the light inlet 51 and exits the reflective cavity 50 through the light outlet 52. Since the light entrance 51 and the light exit 52 are coaxial and the light beam does not contact the periphery of the opening, the light beam 10 does not enter the reflection surface and is reflected by the total reflection light collector 5.

The shape of the reflective cavity 50 is not particularly limited, such as regular polyhedron, ellipsoid, sphere, and combination of curved surface and plane, and the reflective surface facing the photodetector region is preferably a smooth concave curved surface, i.e. the reflective surface region opposite to the photodetector is a smooth concave curved surface; preferably, the photodetector is disposed at a reflection focal point or a near reflection focal point region of the concave curved surface, which is advantageous for receiving scattered light.

The plurality of openings include coaxial inlet 54 and outlet 55 for airflow, and the air path assembly is arranged in combination with the total reflection light collector through the inlet and outlet. Air inlet 71 interfaces with air inlet 54, air inlet 711 can be located inside reflector cavity 50, air inlet 711 can be flush with air inlet 54, and air inlet 711 can also be located outside reflector cavity 50. The exhaust member 72 is abutted with the air outlet 55, the exhaust port 721 can be located inside the reflective cavity 50, the exhaust port 721 can be flush with the air outlet 55, the exhaust port 721 can also be located outside the reflective cavity 50, and preferably, the air inlet member 71 and the exhaust member 72 partially extend into the reflective cavity 50 and do not reach the photosensitive area. Preferably, the outer surfaces of the portions of the air inlet 71 and the air discharge member 72 extending into the reflective cavity 50 are capable of reflecting light.

The plurality of openings include a detection port 53, the photoelectric detector 6 is combined with the reflection cavity 50 through the detection port 53, the light receiving surface of the photoelectric detector 6 is exposed to the reflection cavity 50 through the detection port 53, and the detection port 53 and the rest of the plurality of openings are provided with reflection surface regions as gaps, namely, the detection port 53 and the light inlet 51, the light outlet 52, the light inlet 54 and the air outlet 55 are provided with reflection surface regions as gaps, so that the light beam 10 is prevented from being incident on the light receiving surface of the photoelectric detector 6, and the detection accuracy is ensured.

The axes of the light inlet and the light outlet are coplanar with the axes of the air inlet and the air outlet.

The housing has a passage through which the light beam propagates, the passage, the light inlet and the light outlet being coaxial.

The total reflection light collector 5 has an outer surface outside, and at least a partial region of the outer surface is a light absorption surface. The absorption surface can be formed by coating a coating capable of absorbing light, and can also be formed by blackening treatment and the like, and the light absorption rate is more than 99%. Preferably, the absorption surface is arranged around each opening.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A scattered light collecting and measuring component is applied to a particle counting sensor, and the particle counting sensor comprises a shell, a light path component, a gas path component and a scattered light collecting and measuring component, wherein the light path component is combined with the shell and used for emitting and recovering light beams; the particle scattering measurement device is characterized in that the scattered light collection measurement component comprises a total reflection light collector and a photoelectric detector combined with the total reflection light collector, the total reflection light collector surrounds the photosensitive area, a reflection surface is arranged inside the total reflection light collector and used for collecting scattered light and guiding the scattered light to the photoelectric detector, the reflection surface surrounds the photosensitive area to form a reflection cavity, a plurality of openings corresponding to light beam transmission, air flow circulation and photoelectric detector installation are formed in the total reflection light collector, and light beams and air flows passing through the openings are not in contact with the periphery of the openings.

2. The scattered light collection measurement assembly of claim 1, wherein the plurality of openings comprise coaxial light entry and exit ports for light beams to travel, the light beams entering the reflective cavity through the light entry port and exiting the reflective cavity through the light exit port.

3. The scattered light collection measurement assembly of claim 1, wherein the plurality of openings comprise a detection port through which the photodetector is disposed in conjunction with the reflective cavity, the detection port and the remaining plurality of openings each having the reflective surface area therebetween as a gap.

4. The scattered light collection measurement assembly of claim 2, wherein the plurality of openings comprise coaxial air inlets and outlets for air flow therethrough, the air channel assembly being disposed in conjunction with the total reflection light collector through the air inlets and outlets.

5. The scattered light collection measurement assembly of claim 4, wherein the axes of the light inlet and the light outlet are coplanar with the axes of the air inlet and the air outlet.

6. The scattered light collection measurement assembly of claim 2, wherein the housing has a passage through which the beam of light propagates, the passage, the light inlet and the light outlet being coaxial.

7. The scattered light collection measurement assembly of claim 1, wherein the reflective surface is a smooth concave curve facing the photodetector region.

8. The scattered light collection measurement assembly of claim 1, wherein the reflective surface has a light reflectance of 99% or more.

9. The scattered light collection measurement assembly of claim 1, wherein the fully reflective concentrator has an outer surface on the outside, at least a portion of the outer surface being a light absorbing surface.