A transmission-type smokemeter calibration device

Abstract

The application discloses a kind of transmission smokemeter calibration devices, including industrial computer, measured transmission smokemeter, optical filter storage bin;Optical filter storage bin includes storage bin body, several placement plates and several door buckle switches;Two sides of adjacent of storage bin body are hollowed out, rotating groove is equipped in storage bin body, rotating groove is communicated with the two sides of adjacent of storage bin body, rotating groove is equipped with the rotating shaft of longitudinal arrangement, each placement plate is sequentially rotatably sleeved on rotating shaft from top to bottom, there is preset gap between the adjacent two placement plates of longitudinal arrangement, placement slot is opened in placement plate, and the shape of placement slot is adapted to standard optical filter;The side of placement plate towards the inside of storage bin is equipped with draw hook, and draw hook is adapted to the shape of door buckle switch;Each door buckle switch is vertically arranged on the inner side wall of storage bin body, and the position of door buckle switch and placement plate corresponds in the inside of storage bin body.The application improves the efficiency and convenience of accessing standard optical filter.

Description

Technical Field

[0001] This invention relates to the field of filter calibration technology, and more particularly to a transmission-type smoke meter calibration device. Background Technology

[0002] Strictly enforcing vehicle emissions testing procedures and ensuring the accuracy and reliability of instrument measurements are essential requirements for environmental regulation. Transmission smoke meters are instruments used to measure air pollutants in vehicle exhaust. Their measurement principle is based on the attenuation rate of incident light passing through the smoke column being measured. To ensure the traceability and reliability of transmission smoke meter readings, periodic calibration is necessary. The calibration process requires inserting a standard filter into the transmission smoke meter. Standard filters are typically stored in a case. Currently, retrieving a specific standard filter from the case is inconvenient; it requires opening the case lid, emptying all the standard filters, and searching through them one by one, which is time-consuming and laborious, impacting the calibration efficiency of the transmission smoke meter. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a transmission-type smoke meter calibration device to improve the efficiency and convenience of accessing standard filters.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a transmission smoke meter calibration device, comprising an industrial control computer, a transmission smoke meter under test, and a filter storage compartment. The transmission smoke meter under test includes a host computer and a slave computer. The host computer is communicatively connected to the slave computer, and the industrial control computer is communicatively connected to both the slave computer and the filter storage compartment.

[0005] The filter storage compartment includes a storage compartment body, several placement plates, and several door latches;

[0006] The storage compartment is provided with a rotating groove, which is connected to the two adjacent sides of the storage compartment. A longitudinally arranged rotating shaft is provided in the rotating groove. Each of the placement plates is rotatably sleeved on the rotating shaft from top to bottom. A preset gap is left between two adjacent longitudinally arranged placement plates. The placement plate is provided with a placement groove for placing a standard filter. The placement groove is adapted to the shape of the standard filter. A first number is provided on the side of the placement plate away from the inside of the storage compartment. A second number is provided on the standard filter. The first number corresponds to the second number.

[0007] The placement plate is provided with a hook on the side facing the inside of the storage compartment, and the hook is adapted to the shape of the door latch switch;

[0008] Each of the door latches is longitudinally spaced on the inner sidewall of the storage compartment, and the door latches correspond to the placement plate inside the storage compartment.

[0009] When the placement plate is pressed and rotated toward the rotating groove, the hook engages with the door latch switch. When the placement plate is pressed again, the hook disengages from the door latch switch, and the door latch switch ejects the placement plate to the outside of the storage compartment.

[0010] Furthermore, the industrial control computer includes a main control device, a display and operation device, an image acquisition device, a first wireless communication device, and a power supply device. The display and operation device, the image acquisition device, the first wireless communication device, and the power supply device are electrically connected to the main control device. The storage compartment is equipped with a second wireless communication device, and the first wireless communication device is wirelessly connected to the second wireless communication device.

[0011] Furthermore, the storage compartment is also equipped with a backlit viewing window and a power supply device. The power supply device is electrically connected to the backlit viewing window and the second wireless communication device, and the backlit viewing window is connected to the second wireless communication device.

[0012] Furthermore, the first wireless communication device and the second wireless communication device are radio frequency transceiver modules, and the model of the radio frequency transceiver module is RF433.

[0013] Furthermore, the host computer is equipped with a display screen, and the image acquisition device also includes a lighting source, which faces the display screen and is used to illuminate the display screen.

[0014] Furthermore, the door latch switch includes a housing, a latch, a lock, and a spring. The housing has a guide groove, the latch connects to the lock, the two ends of the spring are respectively connected to the housing and the lock, and the pull hook is adapted to the shape of the lock.

[0015] Furthermore, the main control device is a control chip, and the model of the control chip is STM32F417.

[0016] Furthermore, the industrial control computer also includes a storage device connected to the main control device, used to save the first absorption ratio measurement value of each of the standard filters detected by the lower-level machine and the standard reference value of each of the standard filters. The image acquisition device is used to acquire the detection image of the transmissive smoke meter under test in real time.

[0017] The main control device includes an image recognition unit, a first comparison unit, and a second comparison unit;

[0018] The image recognition unit is used to identify the detected image according to the image recognition algorithm to obtain a second absorption ratio measurement value;

[0019] The first comparison unit is connected to the image recognition unit and is used to compare the first absorption ratio measurement value with the standard reference value, generate a detection command when the first absorption ratio measurement value is the same as the standard reference value, and generate a calibration command when the first absorption ratio measurement value is different from the standard reference value.

[0020] The image recognition unit of the second comparison unit is used to compare the second absorption ratio measurement value with the standard reference value, and generate the detection command when the second absorption ratio measurement value is the same as the standard reference value, and generate the calibration command when the second absorption ratio measurement value is different from the standard reference value;

[0021] The lower-level machine continuously detects the standard filter according to the detection command, and automatically calibrates the accuracy according to the calibration command.

[0022] Furthermore, the image recognition unit includes a preprocessing subunit, a noise processing subunit, and a character recognition subunit;

[0023] The preprocessing subunit is used to sequentially perform image cropping, image grayscale conversion, and binarization on the detected image to obtain a first processed image;

[0024] The noise processing subunit is connected to the preprocessing subunit and is used to process the noise in the first processed image according to the bilateral filtering algorithm to obtain the second processed image;

[0025] The character recognition subunit is connected to the noise processing unit and is used to segment the second processed image into several individual characters based on a threshold, and to identify each character using a template matching algorithm to obtain the second absorption ratio measurement value.

[0026] Furthermore, the storage device is a storage chip, the model of which is MT29F4G08. The storage chip stores a calibration database, and the first absorption ratio measurement value and the value stored in the calibration database are stored in the database.

[0027] The beneficial effects of this invention are:

[0028] This invention incorporates several latch switches inside the storage compartment. These latch switches engage with hooks on the vertically arranged placement plates. Pressing once engages the placement plate, retrieving it into a rotating slot. Pressing again disengages the latch, ejecting the placement plate to the outside of the storage compartment. This facilitates easy access to standard filters on the placement plates, improving the convenience of standard filter retrieval. Furthermore, by assigning a first number corresponding to each standard filter to the side of the placement plate, users can quickly and accurately locate the specific filter they wish to access, further enhancing the efficiency of standard filter retrieval. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the internal structure of the filter storage compartment in this invention;

[0030] Figure 2 This is an enlarged structural diagram of point A in this invention;

[0031] Figure 3 This is a schematic diagram of the external structure of the filter storage compartment in this invention;

[0032] Figure 4 This is a schematic diagram of the connection structure between the transmissive smoke meter being measured and the industrial control computer in this invention;

[0033] Figure 5 This is a control principle diagram of the main control device in this invention;

[0034] Figure 6 This is a time comparison chart of the verification methods in this invention.

[0035] Reference numerals: 1. Filter storage compartment; 11. Storage compartment body; 110. Rotating groove; 12. Placement plate; 13. Door latch switch; 131. Outer shell; 133. Lock; 134. Spring; 14. Rotating shaft; 15. Standard filter; 16. Hook; 17. Backlit viewing window; 18. Charging interface; 19. Second wireless communication device; 2. Industrial control computer; 21. Display and operation device; 22. Industrial camera; 23. Lighting source; 24. First wireless communication device; 3. Host computer; 31. Display screen; 4. Sub-computer; 5. Storage device; 6. Main control device; 61. Image recognition unit; 611. Preprocessing sub-unit; 612. Noise processing sub-unit; 613. Character recognition sub-unit; 62. First comparison unit; 63. Second comparison unit. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0037] like Figures 1 to 4 As shown, a transmission smoke meter calibration device of this embodiment includes an industrial control computer 2, a transmission smoke meter under test, and a filter storage compartment 1. The transmission smoke meter under test includes a host computer 3 and a slave computer 4. The host computer 3 is communicatively connected to the slave computer 4, and the industrial control computer 2 is communicatively connected to the slave computer 4 and the filter storage compartment 1 respectively.

[0038] The filter storage compartment 1 includes a storage compartment body 11, several placement plates 12, and several door latches 13;

[0039] The storage compartment 11 is provided with a rotating groove 110, which is connected to the two adjacent sides of the storage compartment 11. The rotating groove 110 is provided with a longitudinally arranged rotating shaft 14. Each placement plate 12 is rotatably sleeved on the rotating shaft 14 from top to bottom. A preset gap is left between two adjacent placement plates 12 arranged longitudinally. The placement plate 12 is provided with a placement groove for placing a standard filter 15. The placement groove is adapted to the shape of the standard filter 15. The side of the placement plate 12 away from the inside of the storage compartment is provided with a first number, and the standard filter 15 is provided with a second number. The first number corresponds to the second number.

[0040] A hook 16 is provided on the side of the placement plate 12 facing the inside of the storage compartment, and the hook 16 is adapted to the shape of the door latch switch 13;

[0041] Each door latch switch 13 is longitudinally spaced on the inner side wall of the storage compartment 11, and the door latch switch 13 corresponds to the placement plate 12 inside the storage compartment 11.

[0042] When the placement plate 12 is rotated towards the rotating groove 110 and pressed, the hook 16 engages with the door latch switch 13. When the placement plate 12 is pressed again, the hook 16 disengages from the door latch switch 13, and the door latch switch 13 ejects the placement plate 12 to the outside of the storage compartment 11.

[0043] Specifically, in this embodiment, by providing several latch switches 13 inside the storage compartment 11, the latch switches 13 can engage with the hooks 16 on each of the longitudinally arranged placement plates 12. Pressing once engages the placement plate 12 into the rotating groove 110, and pressing again disengages it, ejecting the placement plate 12 to the outside of the storage compartment 11. This facilitates access to the standard filters 15 on the placement plates 12, improving the convenience of accessing the standard filters 15. Simultaneously, by providing a first number corresponding to the standard filters 15 on the side of the placement plates 12, users can quickly and accurately locate the specific filter to be accessed, improving the efficiency of accessing the standard filters 15. The storage compartment 11 is made of a non-magnetic material with a non-slip surface, allowing for handheld use.

[0044] Preferably, the door latch switch 13 includes a housing 131, a latch, a lock 133, and a spring 134. The housing 131 has a guide groove, the latch connects to the lock 133, the two ends of the spring 134 are respectively connected to the housing 131 and the lock 133, and the hook 16 is adapted to the shape of the lock 133.

[0045] Specifically, in this embodiment, when the placement plate 12 is pressed towards the inside of the storage compartment 11 until the latch 133 locks the hook 16, the placement plate 12 is stored inside the rotating groove 110; when the placement plate 12 is pressed again, the hook 16 is disengaged from the latch 133, and at the same time the spring 134 pushes the outer shell 131 outward, so that the placement plate 12 is ejected to the outside of the storage compartment 11.

[0046] Preferably, the industrial control computer 2 includes a main control device 6, a display and operation device 21, an image acquisition device, a first wireless communication device 24, and a power supply device. The display and operation device 21, the image acquisition device, the first wireless communication device 24, and the power supply device are electrically connected to the main control device 6. A second wireless communication device 19 is provided on the storage compartment 11, and the first wireless communication device 24 is wirelessly connected to the second wireless communication device 19.

[0047] Preferably, the main control device 6 is a control chip, specifically an STM32F417. The STM32F417 has abundant peripheral resources to meet the needs of this invention, powerful DSP and FPU resources which are beneficial for the operation of image recognition algorithms, high-speed memory and a high operating frequency of up to 168MHz, which is beneficial for multitasking. It also has a DCMI interface for receiving high-speed data streams from the CMOS sensor camera and an FMC interface for driving SRAM.

[0048] Preferably, the first wireless communication device 24 and the second wireless communication device 19 are radio frequency transceiver modules, the model of which is RF433. The wireless transmission distance of the RF433 radio frequency transceiver module is more than 100 meters, which can ensure the distance and stability of wireless communication.

[0049] Preferably, the image acquisition module includes an industrial camera 22, which is an OmniVision OV7670 camera with a FIFO module. The OV7670 is a 300,000-pixel CMOS image sensor. The OV7670 is controlled by an SCCB bus. In this invention, the I2C interface of the STM32 is used to simulate the SCCB, enabling the main control module to control the operating parameters of the industrial camera 22. The data transmission lines of the OV7670 are connected to the pins of the STM32 with DCMI mapping function, and image data is directly transferred to the STM32F417 memory using Direct Memory Access (DMA) with double buffering processing function.

[0050] Specifically, in this embodiment, the main control device 6 is connected to the image acquisition device via an I2C interface, to the display operation device 21 via a USART interface, to the first wireless communication device 24 via a serial port, and to the lower-level machine 4 via an RS232 interface. The image acquisition device is used to acquire the detection image of the tested transmission smoke meter in real time. The main control device 6 runs a main control program, which builds a Qt environment on an embedded Linux system to create a display interface for display on the display operation device 21. During the programming of the main control program, multi-threaded programming is adopted to take into account the actual needs of the system, mainly separating the operation interface thread and the background working thread. The background working thread can be created or destroyed according to the user's instructions, so that detection control, image acquisition, data processing and other operations can be performed in parallel. After the user sets the detection parameters, the main control program automatically communicates with the lower-level machine 4 to obtain the relevant parameters of the tested transmission smoke meter. The main control program obtains the actual measured value of the tested transmission smoke meter through the communication protocol as the first absorption ratio measurement value.

[0051] Preferably, the display operation device 21 is a DMG64480T035_01W 3.5-inch backlit capacitive touch screen with a resolution of 640×480, and the baud rate for communication with the main control device 6 is set to 115200.

[0052] Preferably, the industrial computer 2 has a circuit board inside, and the front of the industrial computer 2 is provided with a display operation device 21 and a first wireless communication device 24. The touch display operation device 21 is connected to the internal circuit board, and the control chip is integrated on the circuit board.

[0053] Preferably, the host computer 3 is equipped with a display screen 31, and the image acquisition device also includes an illumination source 23, which faces the display screen 31 and is used to illuminate the display screen 31.

[0054] Specifically, in this embodiment, the transmissive smoke meter under test includes a host computer 3 and a slave computer 4. The host computer 3 is used to display the actual measured value through the display screen 31, and the slave computer 4 is used to detect the actual measured value. There is a power supply line between the two, and the slave computer 4 is connected to the industrial control computer 2 through an RS232 transmission line.

[0055] Preferably, the back of the industrial computer 2 is equipped with an industrial camera 22, an illumination source 23, a power interface and an RS232 interface. The industrial camera 22 needs to be aligned with the display screen 31 of the smoke meter host computer 3 in order to collect detection images. The illumination source 23 is used to illuminate the display screen 31 of the host computer 3. The RS232 interface is the smoke meter interface. The industrial computer 2 is connected to the slave computer 4 through an RS232 transmission line, and the power interface is connected to the power supply device.

[0056] Preferably, the power supply device is responsible for supplying power to the industrial computer 2. The power supply device uses an isolated multi-channel circuit to output voltage, ensuring that each working module is independent of each other, reducing interference, and improving the operational stability of the industrial computer 2.

[0057] Preferably, the storage compartment 11 is also provided with a backlit viewing window 17 and a power supply device. The power supply device is electrically connected to the backlit viewing window 17 and the second wireless communication device 19. The backlit viewing window 17 is connected to the second wireless communication device 19.

[0058] Specifically, in this embodiment, the storage compartment 11 receives standard reference values ​​via the second wireless communication device 19 and displays them through the backlit viewing window 17. The power supply can also be charged via the charging port.

[0059] Preferred, such as Figure 5 As shown, the industrial computer 2 also includes a storage device 5, which is connected to the main control device 6 and is used to save the first absorption ratio measurement value of each standard filter 15 detected by the lower computer 4 and the standard reference value of each standard filter 15. The storage device 5 is a storage chip, the model of which is MT29F4G08. The storage chip stores a calibration database, the first absorption ratio measurement value, and the value stored in the calibration database.

[0060] The main control device 6 includes an image recognition unit 61, a first comparison unit 62, and a second comparison unit 63;

[0061] Image recognition unit 61 is used to recognize the detected image according to an image recognition algorithm to obtain a second absorption ratio measurement value;

[0062] The first comparison unit 62 is connected to the image recognition unit 61 and is used to compare the first absorption ratio measurement value with the standard reference value, generate a detection command when the first absorption ratio measurement value is the same as the standard reference value, and generate a calibration command when the first absorption ratio measurement value is different from the standard reference value.

[0063] The second comparison unit 63 and the image recognition unit 61 are used to compare the second absorption ratio measurement value with the standard reference value, generate a detection command when the second absorption ratio measurement value is the same as the standard reference value, and generate a calibration command when the second absorption ratio measurement value is different from the standard reference value.

[0064] The lower-level machine 4 continuously detects the standard filter 15 according to the detection command, and automatically calibrates the accuracy according to the calibration command.

[0065] Specifically, in this embodiment, the accuracy of filter detection is effectively improved by comparing and calibrating twice.

[0066] Preferably, the image recognition unit 61 includes a preprocessing subunit 611, a noise processing subunit 612, and a character recognition subunit 613;

[0067] The preprocessing subunit 611 is used to sequentially perform image cropping, image grayscale conversion, and binarization on the detected image to obtain a first processed image;

[0068] The noise processing subunit 612 is connected to the preprocessing subunit 611 and is used to process the noise in the first processed image according to the bilateral filtering algorithm to obtain the second processed image;

[0069] The character recognition subunit 613 is connected to the noise processing unit and is used to segment the second processed image into several individual characters based on a threshold, and to use a template matching algorithm to recognize each character to obtain a second absorption ratio measurement value.

[0070] Specifically, in this embodiment, the preprocessing subunit 611 solves the image blurring problem caused by instrument shaking by using image sharpening processing on the detection image. The noise processing subunit 612 effectively filters out noise in the first processed image using a bilateral filtering algorithm, further improving the image clarity.

[0071] Calibration Process: The testing personnel select three measurement points (high, medium, and low) on the industrial control computer 2 and perform tests sequentially. Each point can be tested three times. The corresponding standard filter 15 pops out from the filter storage compartment 1 by pressing the corresponding placement plate 12. This standard filter is then inserted into the designated position on the transmissive smoke meter under test. The industrial control computer 2 acquires the actual measured value of the transmissive smoke meter through a communication protocol, using this as the first absorption ratio measurement value. The image acquisition module acquires the smoke meter's test image, and the image recognition algorithm is used to process it to obtain the second absorption ratio detection value. This value is then compared with the standard reference value of the absorption ratio of the standard filter 15. If the measurement is repeated three times, the average of the three readings is taken as the detection value. The industrial control computer 2 then reads the standard reference value from the calibration database, records the test results, and outputs the original record. If the second test is the same as the first, the process ends; otherwise, automatic calibration continues. After the test, the original record can be output as needed.

[0072] In addition, a comparative test was conducted with the manual calibration method, and the comparative test results are as follows: Figure 6 As shown, the time consumption calculation includes the total time from the start of the test on the smoke meter to the generation of the original record.

[0073] from Figure 6 As can be seen, the calibration time has been reduced by approximately 70%, greatly improving calibration efficiency.

[0074] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A calibration device for a transmission-type smoke meter, characterized in that, The device includes an industrial control computer (2), a transmissive smoke meter to be tested, and a filter storage compartment (1). The transmissive smoke meter to be tested includes a host computer (3) and a slave computer (4). The host computer (3) is connected to the slave computer (4) via communication. The industrial control computer (2) is connected to the slave computer (4) and the filter storage compartment (1) via communication. The filter storage compartment (1) includes a storage compartment body (11), several placement plates (12) and several door latches (13); The storage compartment (11) is provided with a rotating groove (110), which is connected to the two adjacent sides of the storage compartment (11). The rotating groove (110) is provided with a longitudinally arranged rotating shaft (14). Each of the placement plates (12) is rotatably sleeved on the rotating shaft (14) from top to bottom. A preset gap is left between two adjacent placement plates (12) arranged longitudinally. The placement plate (12) is provided with a placement groove for placing a standard filter (15). The placement groove is adapted to the shape of the standard filter (15). The side of the placement plate (12) away from the storage compartment (11) is provided with a first number, and the standard filter (15) is provided with a second number. The first number corresponds to the second number. The placement plate (12) is provided with a hook (16) on the side facing the inside of the storage compartment, and the hook (16) is adapted to the shape of the door latch switch (13); Each of the door latch switches (13) is longitudinally spaced on the inner side wall of the storage compartment (11), and the door latch switches (13) and the placement plate (12) are positioned correspondingly inside the storage compartment (11); When the placement plate (12) is pressed towards the rotating groove (110), the hook (16) engages with the door latch switch (13). When the placement plate (12) is pressed again, the hook (16) disengages from the door latch switch (13), and the door latch switch (13) ejects the placement plate (12) to the outside of the storage compartment (11).

2. The transmission-type smoke meter calibration device according to claim 1, characterized in that: The industrial control computer (2) includes a main control device (6), a display operation device (21), an image acquisition device, a first wireless communication device (24), and a power supply device. The display operation device (21), the image acquisition device, the first wireless communication device (24), and the power supply device are electrically connected to the main control device (6). The storage compartment (11) is equipped with a second wireless communication device (19), and the first wireless communication device (24) is wirelessly connected to the second wireless communication device (19).

3. The transmission-type smoke meter calibration device according to claim 2, characterized in that: The storage compartment (11) is also provided with a backlit viewing window (17) and a power supply device. The power supply device is electrically connected to the backlit viewing window (17) and the second wireless communication device (19). The backlit viewing window (17) is connected to the second wireless communication device (19).

4. The transmission-type smoke meter calibration device according to claim 2, characterized in that: The first wireless communication device (24) and the second wireless communication device (19) are radio frequency transceiver modules, and the model of the radio frequency transceiver module is RF433.

5. The calibration device for a transmission-type smoke meter according to claim 2, characterized in that: The host computer (3) is equipped with a display screen (31), and the image acquisition device also includes an illumination source (23), which faces the display screen (31) and is used to illuminate the display screen (31).

6. The calibration device for a transmission-type smoke meter according to claim 1, characterized in that: The door latch switch (13) includes a housing (131), a pull rod, a latch (133), and a spring (134). The housing (131) has a guide groove. The pull rod is connected to the latch (133). The two ends of the spring (134) are respectively connected to the housing (131) and the latch (133). The hook (16) is adapted to the shape of the latch (133).

7. The transmission-type smoke meter calibration device according to claim 2, characterized in that: The main control device (6) is a control chip, and the model of the control chip is STM32F417.

8. The calibration device for a transmission-type smoke meter according to claim 2, characterized in that: The industrial control computer (2) also includes a storage device (5) connected to the main control device (6), used to save the first absorption ratio measurement value of each of the standard filters (15) detected by the lower computer (4) and the standard reference value of each of the standard filters (15). The image acquisition device is used to acquire the detection image of the transmissive smoke meter under test in real time. The main control device (6) includes an image recognition unit (61), a first comparison unit (62), and a second comparison unit (63); The image recognition unit (61) is used to recognize the detected image according to the image recognition algorithm to obtain a second absorption ratio measurement value; The first comparison unit (62) is connected to the image recognition unit (61) and is used to compare the first absorption ratio measurement value with the standard reference value, generate a detection command when the first absorption ratio measurement value is the same as the standard reference value, and generate a calibration command when the first absorption ratio measurement value is different from the standard reference value. The image recognition unit (61) of the second comparison unit (63) is used to compare the second absorption ratio measurement value with the standard reference value, and generate the detection command when the second absorption ratio measurement value is the same as the standard reference value, and generate the calibration command when the second absorption ratio measurement value is different from the standard reference value; The lower-level machine (4) continuously detects the standard filter (15) according to the detection command, and automatically calibrates the accuracy according to the calibration command.

9. The calibration device for a transmission-type smoke meter according to claim 8, characterized in that: The image recognition unit (61) includes a preprocessing subunit (611), a noise processing subunit (612), and a character recognition subunit (613); The preprocessing subunit (611) is used to sequentially perform image cropping, image grayscale conversion, and binarization on the detected image to obtain a first processed image; The noise processing subunit (612) is connected to the preprocessing subunit (611) and is used to process the noise in the first processed image according to the bilateral filtering algorithm to obtain the second processed image; The character recognition subunit (613) is connected to the noise processing subunit and is used to segment the second processed image into several individual characters based on a threshold, and to use a template matching algorithm to identify each character to obtain the second absorption ratio measurement value.

10. The transmission-type smoke meter calibration device according to claim 8, characterized in that: The storage device (5) is a storage chip, the model of which is MT29F4G08. The storage chip stores a calibration database, and the first absorption ratio measurement value and the value stored in the calibration database are stored in the calibration database.

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