Backscatter smoke instrument automatic calibration device
Patent Information
- Application Number
- CN202522440176.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-11-18
AI Technical Summary
[0002]目前有四种常见的测量烟尘颗粒物的基本方法：电荷法、光学浊度法、β射线法和光散射法，其中，光散射法适用于测量低浓度烟尘颗粒物，而光散射法烟尘仪根据光源与光学传感器的相对角度可分为：前散射、后散射和侧散射三种类型仪表；前散射烟尘仪的优点是可以准确测量粒径PM 1.0烟尘颗粒物，但是结构较为复杂，且该类烟尘仪的光学元件与烟气长时间接触容易被污染，维护成本相对较高；侧散射烟尘仪安装较为复杂，现场必须预留发射和接收两个测量孔，维护量量较大；后散射烟尘仪采用简单便捷的单侧开孔安装，设备不与烟气直接接触，但缺点是测量PM1.0烟尘颗粒物不准确；因此，与其他两款类型仪表比较，后散射烟尘仪的性价比相对较高，安装和维护便捷，而在光学传感器的灵敏度进行升级改进后，用光学校准镜片模块定期校准可弥补测量PM1.0不准确的缺点；但是，后散射烟尘仪内部的激光器光源衰减、检测器灵敏度降低、机械零件的安装失误等因素会加大测量误差，以及除上述问题以外，光学镜片污染也会导致零点和量程的偏移和降低测量的准确性；因此，后散射烟尘仪只有消除颗粒物对光学镜片污染的影响（具备镜片污染度补偿功能）或者对仪表进行零点和量程校准，才能真正实现稳定准确测量低浓度颗粒物的可能
[0007] The beneficial effect of this utility model is that it drives the calibration plate to rotate via a stepper motor, thereby switching between measurement and calibration states. This not only enables the calibration of the calibration mirrors in the calibration lens group, but also ensures the cleanliness of the calibration mirrors and guarantees measurement accuracy, thus having good practical value.
Smart Images
Figure CN224861520U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of smoke and dust treatment technology, specifically to an automatic calibration device for a backscattering smoke and dust meter. Background Technology
[0002] There are currently four common basic methods for measuring particulate matter: charge method, optical turbidity method, beta-ray method, and light scattering method. Among these, the light scattering method is suitable for measuring low-concentration particulate matter. Light scattering dust meters can be classified into three types based on the relative angle between the light source and the optical sensor: forward scattering, backscattering, and side scattering. Forward scattering dust meters have the advantage of accurately measuring PM1.0 particles, but their structure is relatively complex, and the optical elements are easily contaminated due to prolonged contact with the flue gas, resulting in relatively high maintenance costs. Side scattering dust meters are more complex to install, requiring two measurement holes for both transmission and reception, leading to greater maintenance requirements. Backscattering dust meters use a simple and convenient single-sided opening installation, avoiding direct contact with the flue gas, but their disadvantage is inaccurate measurement of PM1.0 particles. Therefore, compared to the other two types of instruments, backscattering dust meters offer a relatively higher cost-performance ratio, are easier to install and maintain, and require upgrades to improve the sensitivity of the optical sensor. Afterwards, periodic calibration with an optical calibration lens module can compensate for the inaccuracy in PM1.0 measurement; however, factors such as laser light source attenuation, detector sensitivity reduction, and mechanical part installation errors inside the backscattering dust meter can increase measurement errors. In addition to the above problems, optical lens contamination can also cause zero-point and range shifts and reduce measurement accuracy. Therefore, only by eliminating the influence of particulate matter on optical lens contamination (having lens contamination compensation function) or by calibrating the instrument's zero point and range can a backscattering dust meter truly achieve stable and accurate measurement of low-concentration particulate matter.
[0003] Traditionally, optical lens contamination is addressed by backflushing the lenses with a backflushing air source. While this may ensure short-term zero-point and range drift compliance if the air source is of high quality, manual cleaning of the lenses is still required in the long term. Therefore, to achieve long-term stable and accurate measurement of low-concentration particulate matter, regular automatic zero-point and range drift calibration, as well as lens contamination compensation, are necessary. Furthermore, current light scattering dust analyzers typically employ an indirect calibration method using a light scattering calibration module to calibrate particulate matter concentration. Thus, in addition to automatic calibration and optical lens purging, the light scattering lens of the light scattering calibration module must also be purged to prevent contamination and ensure the accuracy of optical standard materials. Utility Model Content
[0004] To address the aforementioned issues, this invention provides an automatic calibration device for backscattering dust meters, which ensures the cleanliness of the calibration optical lenses and guarantees measurement accuracy.
[0005] This utility model adopts the following technical solution: an automatic calibration device for a backscattering dust meter, comprising a housing, inside which is installed a laser and a signal collection and processing mechanism. The laser beam emitted by the laser is transmitted to the measurement area through a filter lens. The scattered light reflected by particles in the measurement area passes through an optical lens and reaches the signal collection and processing mechanism to achieve the measurement of dust particles. The housing also includes a rotating calibration mechanism, which includes a protective cover and a calibration plate. The protective cover is installed on the outside of the housing, and a stepper motor for driving the calibration plate to rotate is installed inside the protective cover to achieve the switching between measurement and calibration states. The calibration plate is provided with an emitting light aperture and a receiving light aperture respectively facing the filter lens and the optical lens. The calibration plate is symmetrically arranged with calibration lens groups, with two sets of calibration lens groups located on both sides of the emitting light aperture and the receiving light aperture, respectively. Each set of calibration lens groups includes two calibration mirrors to form an optical channel to receive the transmitted light from the filter lens and reflect the transmitted light to the optical lens. The housing is provided with a purge port arranged on one side corresponding to the calibration plate.
[0006] Furthermore, the protective cover is provided with a purge air inlet, and the purge air enters the housing after passing through the purge air inlet, the protective cover, and the purge port in sequence; Furthermore, the signal collection and processing mechanism includes: A laser drive control module, connected to the laser, is used to drive the laser to emit laser light; A signal processing module is used to receive the scattered light signal reflected by particles in the measurement area via the optical lens; The power supply and input / output interface module is used to provide power and communicate with external devices. The main control display module is connected to the laser drive control module, signal processing module, power supply and input / output interface module. It is used to control the operation of each module and display the measurement status and calibration status based on the received optical signal. Furthermore, the protective cover is installed on the top of the housing, and the drive end of the stepper motor extends into the housing and is connected to the calibration plate. The drive motor drives the calibration plate to rotate 90°~180° to switch between measurement and calibration states. Furthermore, the two sets of calibration lens groups are divided into a first calibration lens group and a second calibration lens group, which are located on both sides of the calibration plate. Each of the first and second calibration lens groups includes two calibration mirrors, which are an incident calibration mirror and an exit calibration mirror. The incident and exit calibration mirrors in the same group are arranged at an angle relative to each other. The incident calibration mirror is used to receive the transmitted light from the filter lens and reflect the transmitted light to the exit calibration mirror. The exit calibration mirror is used to receive the transmitted light and reflect the transmitted light to the optical lens.
[0007] The beneficial effect of this utility model is that it drives the calibration plate to rotate via a stepper motor, thereby switching between measurement and calibration states. This not only enables the calibration of the calibration mirrors in the calibration lens group, but also ensures the cleanliness of the calibration mirrors and guarantees measurement accuracy, thus having good practical value. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the structure of this utility model in the measurement state; Figure 2 This is a schematic diagram of the structure of this utility model in the calibration state. Detailed Implementation
[0009] like Figure 1 , Figure 2 As shown, the automatic calibration device for backscattering dust meter of this utility model includes a housing 14. A laser 3 and a signal collection and processing mechanism are installed inside the housing 14. The laser beam emitted by the laser 3 is transmitted to the measurement area through a filter lens 5. The scattered light reflected by particles in the measurement area passes through an optical lens 4 and reaches the signal collection and processing mechanism to measure the dust particles. A rotating calibration mechanism is also installed inside the housing 14. The rotating calibration mechanism includes a protective cover 15 and a calibration plate 16. The protective cover 15 is installed on the outside of the housing 14, and a stepper motor 12 is installed inside the protective cover 15 to drive the calibration plate 16 to rotate, thereby switching between measurement and calibration states. The calibration plate 16 has sections facing the filter... Lens 5 and optical lens 4 have an emitting aperture 11 and a receiving aperture 10. The diameter of the receiving aperture 10 is larger than the diameter of the emitting aperture 11, which can achieve better reception of scattered light reflected by particles in the measurement area. The calibration plate 16 is symmetrically provided with calibration lens groups. The two calibration lens groups are located on both sides of the emitting aperture 11 and the receiving aperture 10, respectively. Each calibration lens group includes two calibration mirrors to form an optical channel to receive the transmitted light from the filter lens 5 and reflect the transmitted light to the optical lens 4. The housing 14 is provided with a purge port 17 corresponding to one side of the calibration plate 16. That is, the purge port 17 corresponds to the first calibration lens group 8, so that the first calibration lens group 8 is always in a backflushing state.
[0010] The protective cover 15 is provided with a purge air inlet 13. The purge air enters the housing 14 after passing through the purge air inlet 13, the protective cover 15, and the purge port 17 in sequence.
[0011] The signal collection and processing mechanism includes: a laser drive control module 2, which is connected to the laser 3 and is used to drive the laser 3 to emit laser light; Signal processing module 7 is used to receive the scattered light signal reflected by particles in the measurement area via optical lens 4; The power supply and input / output interface module 6 is used to provide power and data communication with external devices. The main control display module 1 is connected to the laser drive control module 2, the signal processing module 7, the power supply and input / output interface module 6. It is used to control the operation of each module and to display the measurement status and calibration status based on the received optical signal.
[0012] The protective cover 15 is installed on the top of the housing 14. The drive end of the stepper motor 12 extends into the housing 14 and is connected to the calibration plate 16. The drive motor drives the calibration plate 16 to rotate 90°~180° to switch between measurement and calibration states.
[0013] The two sets of calibration lens groups are divided into a first calibration lens group 8 and a second calibration lens group 9, which are located on both sides of the calibration plate 16. Each of the first calibration lens group 8 and the second calibration lens group 9 includes two calibration mirrors, which are an incident calibration mirror 18 and an exit calibration mirror 19. The incident calibration mirror 18 and the exit calibration mirror 19 in the same group are set at an angle relative to each other. The incident calibration mirror 18 is used to receive the transmitted light from the filter lens 5 and reflect the transmitted light to the exit calibration mirror 19. The exit calibration mirror 19 is used to receive the transmitted light and reflect the transmitted light to the optical lens 4.
[0014] This utility model adopts a vertically mounted stepper motor 12 for rotational drive, realizing the optical lens calibration function of the first calibration lens group 8 and the second calibration lens group 9 on both sides, and avoiding optical lens contamination and motor overheating failure. Specifically, the protective cover 15 is detachably installed on the top of the housing 14, so the stepper motor 12 can be easily disassembled and assembled after the housing 14 is disassembled. The back-blowing air enters the housing 14 through the blow air inlet 13, the protective cover 15, and the blow port 17. Through the blow port 17 arranged on one side of the corresponding calibration plate 16, the calibration lens on the corresponding side can be blown from the top of the housing 14, and the stepper motor 12 can also be cooled. The first calibration lens group 8 and the second calibration lens group 9 are located on both sides of the emitting light aperture 11 and the receiving light aperture 10, respectively. That is, the first calibration lens group 8 is always in backflushing during measurement, while the second calibration lens group 9 is not in backflushing. When the signal processing module 7 calibrates the first calibration lens group 8 with backflushing, it can compare the recorded calibration data with the original factory calibration to determine the contamination level of the filter lens 5 and the optical lens 4. When the contamination level exceeds a certain limit, the main control display module 1 will display an alarm to prompt maintenance personnel to clean the corresponding lens. However, the process of comparing the data and judging whether the contamination level exceeds a certain limit is not within the scope of protection of this patent. As prior art, it will not be described in detail here.
[0015] When in measurement mode, stepper motor 12 drives calibration board 16 to rotate, so that filter lens 5 faces the emitting light aperture 11 and optical lens 4 faces the receiving light aperture 10. At this time, the laser beam emitted by laser 3 passes through filter lens 5 and emitting light aperture 11 and is emitted to the corresponding measurement area. Subsequently, the scattered light reflected by particles in the measurement area passes through receiving light aperture 10 and optical lens 4 and reaches signal processing module 7 and main control display module 1 to realize the measurement of smoke and dust particles. When in calibration mode, stepper motor 12 drives calibration plate 16 to rotate, so that filter lens 5 faces the incident calibration mirror 18 in the first calibration lens group 8 and optical lens 4 faces the exit calibration mirror 19 in the first calibration lens group 8. At this time, the laser beam emitted by laser 3 enters the optical channel formed by the first calibration lens group 8, that is, the laser beam passes through filter lens 5, incident calibration mirror 18 in the first calibration lens group 8, exit calibration mirror 19 in the first calibration lens group 8, and optical lens 4 in sequence before reaching signal processing module 7 and main control display module 1 to achieve calibration detection. The collimator 18 and the emission calibration mirror 19 are always under the action of the purge air. Therefore, the calibration test result can be used as the calibration reference data. By comparing the calibration test data with the calibration data at the factory, it can be determined whether the calibration is qualified and valid. If the error between the two is within the range, the dust collector can be calibrated according to the data. When the error between the two exceeds a certain range, it is necessary to check whether there is a problem with the dust collector or the backflushing air. In this way, cleaning and maintenance can be carried out in time before putting it into use, so as to avoid large measurement errors caused by forced calibration. Similarly, the calibration judgment scheme is not within the scope of protection of this patent. As it is prior art, it will not be described in detail. When the stepper motor 12 drives the calibration plate 16 to rotate, the filter lens 5 faces the incident calibration mirror 18 in the second calibration lens group 9, and the optical lens 4 faces the exit calibration mirror 19 in the second calibration lens group 9. At this time, the laser beam emitted by the laser 3 enters the optical channel formed by the second calibration lens group 9. That is, the laser beam passes through the filter lens 5, the incident calibration mirror 18 in the second calibration lens group 9, the exit calibration mirror 19 in the second calibration lens group 9, and the optical lens 4 in sequence before reaching the signal processing module 7 and the main control display module 1 to achieve calibration detection. However, since the incident calibration mirror 18 and the exit calibration mirror 19 in the second calibration lens group 9 do not have a blowing effect, the calibration detection result will have a large deviation. It can only be used as the lens contamination degree detection value to indicate that the lens contamination exceeds the limit alarm and prompt manual cleaning and maintenance.
[0016] In summary, this invention not only calibrates backscatter dust meters and compensates for measurement errors caused by lens contamination, ensuring measurement accuracy, but also features a lens contamination alarm function, reducing equipment maintenance costs and meeting relevant national regulations and standards.
[0017] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0018] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. An automatic calibration device for a backscattering dust meter, comprising a housing, wherein a laser and a signal collection and processing mechanism are disposed within the housing, the laser beam emitted by the laser is transmitted to the measurement area through a filter lens, and the scattered light reflected by particles in the measurement area reaches the signal collection and processing mechanism after passing through an optical lens to achieve the measurement of dust particles; characterized in that: The housing also includes a rotation calibration mechanism, which comprises a protective cover and a calibration plate. The protective cover is installed on the outside of the housing, and a stepper motor is installed inside the protective cover to drive the calibration plate to rotate, thereby switching between measurement and calibration states. The calibration plate has an emitting aperture and a receiving aperture facing the filter lens and the optical lens, respectively. The calibration plate is symmetrically arranged with calibration lens groups, with two sets of calibration lens groups located on both sides of the emitting aperture and the receiving aperture, respectively. Each set of calibration lens groups includes two calibration mirrors to form an optical channel for receiving the transmitted light from the filter lens and reflecting the transmitted light to the optical lens. The housing is provided with a purge port arranged on one side of the calibration plate.
2. The automatic calibration device for backscattering dust meter according to claim 1, characterized in that: The protective cover is provided with a purge air inlet, and the purge air enters the housing after passing through the purge air inlet, the protective cover, and the purge port in sequence.
3. The automatic calibration device for backscattering dust meter according to claim 1, characterized in that: The signal collection and processing mechanism includes: A laser drive control module, connected to the laser, is used to drive the laser to emit laser light; A signal processing module is used to receive the scattered light signal reflected by particles in the measurement area via the optical lens; The power supply and input / output interface module is used to provide power and communicate with external devices. The main control display module is connected to the laser drive control module, signal processing module, power supply and input / output interface module. It is used to control the operation of each module and display the measurement status and calibration status based on the received optical signal.
4. The automatic calibration device for backscattering dust meter according to claim 1, characterized in that: The protective cover is installed on the top of the housing. The drive end of the stepper motor extends into the housing and is connected to the calibration plate. The stepper motor drives the calibration plate to rotate 90°~180° to switch between measurement and calibration states.
5. The automatic calibration device for backscattering dust meter according to claim 1, characterized in that: The two sets of calibration lens groups are divided into a first calibration lens group and a second calibration lens group, which are located on both sides of the calibration plate. Each of the first and second calibration lens groups includes two calibration mirrors, which are an incident calibration mirror and an exit calibration mirror. The incident and exit calibration mirrors in the same group are arranged at an angle relative to each other. The incident calibration mirror is used to receive the transmitted light from the filter lens and reflect the transmitted light to the exit calibration mirror. The exit calibration mirror is used to receive the transmitted light and reflect the transmitted light to the optical lens.