Self-calibration and self-verification device and method for spectrum analyzer

Abstract

The present invention relates to a self-calibration and self-verification device and method for a spectrum analyzer. The device is provided with a driving mechanism and a calibration plate within the analyzer housing. The calibration plate includes a light-blocking plate, a light-blocking plate group, and a packaged calibration block group. A self-calibration control module is respectively connected to the driving mechanism, the spectrometer, and the measurement control module by signal. The driving mechanism drives the calibration plate to move to different positions, including: the center of the light-blocking plate is located in the optical path from the light source to the measurement cell, the centers of the light-blocking plates in the light-blocking plate group are respectively located in the optical path from the light source to the measurement cell, the centers of the packaged calibration blocks in the packaged calibration block group are respectively located in the optical path from the light source to the measurement cell, and the light-blocking plate, the light-blocking plate group, and the packaged calibration block group are all withdrawn from the optical path. The method ensures calibration accuracy by sequentially starting a wavelength positioning calibration program, a spectral intensity linearity calibration program, and a calibration accuracy self-verification program, thereby improving the measurement accuracy of the analyzer and enabling timed online calibration.

Description

Technical Field

[0001] The invention relates to a self-calibration and self-verification device and method for a spectrum analyzer, belonging to the technical field of environmental monitoring. Background Art

[0002] Spectrum analyzers are widely used in industries such as metallurgy, geology, hydrology, medicine, petrochemicals, and environmental protection. They primarily analyze the wavelength and intensity of the characteristic spectrum of a sample to determine its properties and content. However, over time, internal temperature fluctuations, as well as minor deformations of optical components and mechanical structures, can cause wavelength drift in the spectrum, resulting in deviations in measurement results. Therefore, my country's latest environmental protection standards explicitly require that spectrum analyzers used for testing must have an automatic calibration function. However, due to the limitations of current testing technology, existing automatic calibration methods and devices cannot operate accurately and reliably over the long term. In addition, the spectrum analyzer calibration methods commonly used in the existing technology mostly adopt wavelength calibration methods, that is, by regularly measuring the spectral wavelength offset and performing wavelength correction on it. One method is to pre-set a calibration program, such as using a polynomial fitting algorithm to correct the wavelength drift. However, this algorithm will cause serious deviations in the fitting function for data points that are slightly far from the fitting point, especially the interpolation points, resulting in low calibration accuracy; the other method is to set up a spectrometer wavelength calibration lamp for calibration, such as mercury argon, krypton, neon, argon and xenon gas lamps. This method not only increases the calibration cost, but also cannot achieve automatic calibration. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, a self-calibration and self-verification device and method for an optical spectrum analyzer are now provided. The device and method can not only calibrate the wavelength of the optical spectrum analyzer, but also calibrate its light intensity and verify whether the self-calibration result is correct. The device and method can accurately monitor abnormal self-calibration conditions, thereby technically ensuring the long-term, accurate and stable operation of the analyzer, with reliable calibration, low cost and automatic calibration.

[0004] To achieve the above-mentioned objectives, the present application provides a self-calibration and self-verification device for an optical spectrum analyzer, comprising an analyzer housing, a measurement control module of the analyzer, a measuring cell, a spectrometer, and a light source, wherein the measuring cell is arranged on one side of the analyzer housing, the light source is arranged on a side of the analyzer housing away from the measuring cell, the light emitted by the light source passes through the measuring cell and enters the spectrometer, and the measurement control module is respectively connected to the light source and the spectrometer signals; the device also includes a self-calibration control module, and a drive mechanism and a calibration piece arranged in the analyzer housing, the calibration piece including a light-blocking piece, a light-blocking piece group, and a packaged calibration block group, the self-calibration control module is respectively connected to the drive mechanism, the spectrometer, and the measurement control module signals; the drive mechanism drives the calibration piece to move to different positions, including: the center of the light-blocking piece is located in the optical path from the light source to the measuring cell, the centers of the light-blocking pieces in the light-blocking piece group are respectively located in the optical path from the light source to the measuring cell, the centers of the packaged calibration blocks in the packaged calibration block group are respectively located in the optical path from the light source to the measuring cell, and the light-blocking piece, the light-blocking piece group, and the packaged calibration block group are all withdrawn from the optical path;

[0005] The light-blocking sheet has a light transmittance of 0; the light-blocking sheet group includes m light-blocking sheets, and the prefabricated light transmittances of the light-blocking sheets are a1, a2...a m , m≥1; the package calibration block group includes n package calibration blocks, n≥1.

[0006] Optionally, the packaged standard block is a sealed container with lenses on both sides, and a medium sample of standard concentration is packaged inside the container; or, an optical filter is provided in the packaged standard block, and the spectral absorption wavelength of the optical filter is the same as the absorption wavelength of the medium sample of standard concentration.

[0007] Optionally, the driving mechanism includes a driving device and a movable arm, the movable arm is connected to the calibration plate, and the light-blocking plate, light-blocking plate group, and packaged calibration block group in the calibration plate are connected in sequence up and down; or, the driving mechanism includes a first driving mechanism and a second driving mechanism, the calibration plate includes a first calibration plate and a second calibration plate, the first driving mechanism is connected to the first calibration plate, the second driving mechanism is connected to the second calibration plate, the first calibration plate includes a light-blocking plate and a packaged calibration block group, and the light-blocking plate and the packaged calibration block group are connected in sequence up and down, the second calibration plate includes a light-blocking plate group, and each light-blocking plate in the light-blocking plate group is connected in sequence up and down; or, the driving mechanism includes a driving device and a crank arm, the crank arm is connected to the calibration plate, and the light-blocking plate, light-blocking plate group, and packaged calibration block group in the calibration plate are arranged in sequence on an arc centered on the driving axis of the driving device.

[0008] A self-calibration and self-verification method for an optical spectrum analyzer comprises the following steps:

[0009] The first step is to start the wavelength positioning calibration. The calibration procedure is as follows:

[0010] ①Pour the medium sample with zero concentration into the measuring cell and fill it up;

[0011] ② The self-calibration control module controls the driving mechanism to move the calibration piece so that the center of any packaged standard block is positioned at the center of the optical path. The measurement control module reads the current measured wavelength value through the spectrometer and sends it to the self-calibration control module;

[0012] ③ The self-calibration control module calculates the wavelength deviation to be calibrated and sends it to the measurement control module for wavelength positioning calibration;

[0013] ④ After the wavelength positioning calibration is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path;

[0014] Step 2: Start the spectral intensity linear calibration. The calibration procedure is as follows:

[0015] ① The self-calibration control module controls the driving mechanism to move the calibration plate so that the center of the light-blocking plate is positioned at the center of the optical path. The self-measurement control module reads the light intensity signal K0 through the spectrometer and sends it to the self-calibration control module;

[0016] ②Pour the medium sample with zero concentration into the measuring cell and fill it up;

[0017] ③ The self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path. The measurement control module reads the light intensity signal K through the spectrometer 100 And send it to the self-calibration control module;

[0018] ④ The self-calibration control module controls the driving mechanism to move the calibration plate and positions the center of each light-blocking plate in the light-blocking plate group at the center of the optical path. The measurement control module reads the current light intensity signals K1, K2, ..., K through the spectrometer. m And send it to the self-calibration control module;

[0019] ⑤ The self-calibration control module writes the measurement results of ①③④ into the preset function of the measurement control module at the same time. The measurement control module performs spectral intensity linear calibration based on the preset transmittance of each light blocker and the current light intensity signal:

[0020] X0=K0 / K 100 ,Y0=0

[0021] X1=K1 / K 100 ,Y1=a1

[0022] X2=K2 / K 100 ,Y2=a2

[0023] …

[0024] X m =K m / K 100 ,Y m =a m

[0025] X 100 =100%,Y 100 =1, where the prefabricated transmittances of the light-blocking sheets in the light-blocking sheet group are a1, a2...a m ;

[0026] ⑥ After the spectral intensity linear calibration is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path.

[0027] Furthermore, the method also includes a calibration accuracy self-verification procedure, the steps of which are as follows:

[0028] ①Pour the medium sample with zero concentration into the measuring cell and fill it up;

[0029] ② The self-calibration control module controls the driving mechanism to move the calibration piece so that the center of each packaged standard block in the packaged calibration block group is positioned at the center of the optical path in turn. The self-calibration control module reads the medium concentration values ​​C1, C2...C detected by the measurement control module in turn. n ;

[0030] ③ The nominal indication value C of the analyzer after the packaged calibration block is inserted into the optical path n0 Compare the result with the medium concentration value detected in step ②. When the difference between the two is greater than the allowable measurement error value, the self-calibration control module will issue a fault alarm.

[0031] ④ After the self-calibration accuracy self-verification program is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path.

[0032] Furthermore, the nominal indication of the analyzer after the packaged calibration block is inserted into the optical path is calculated as follows:

[0033]

[0034] L n2 is the length of the medium sample in the nth package calibration block, L1 is the length in the measuring cell, j is the number of times the light passes through the measuring cell, C nb is the nominal concentration value of the nth packaged calibration block medium sample, C n0 The nominal value of the detection concentration of the analyzer converted from the medium sample in the nth packaged calibration block;

[0035] When ABS(C n -C n0 )>C n1When the self-calibration control module issues a self-calibration out-of-tolerance fault alarm, requesting maintenance;

[0036] When ABS(C n -C n0 )≤C n1 When , the spectrum analyzer's self-calibration procedure runs normally;

[0037] Among them, C n1 The allowable measurement error value of the analyzer self-calibration.

[0038] Optionally, the self-calibration control module calculates the wavelength deviation to be calibrated and sends it to the measurement control module to perform wavelength positioning calibration, which is to perform wavelength positioning calibration on the light emitted by the light source, including:

[0039] ① The self-calibration control module calculates the wavelength difference, △λ=λ 00 -λ 01 , where λ 00 is the central wavelength of the light emitted by the light source, λ 01 The central wavelength value of the absorption peak of the light emitted by the light source after passing through the encapsulated standard block;

[0040] ② The self-calibration control module transmits the wavelength difference to the measurement control module, which adjusts the central wavelength of the light emitted by the light source to λ according to the wavelength difference. 01 .

[0041] Optionally, the self-calibration control module calculates the wavelength deviation to be calibrated and sends it to the measurement control module for wavelength positioning calibration, which is a wavelength positioning calibration for light intensity calculation, including:

[0042] ① The self-calibration control module reads the wavelength λ of the absorption peak in the packaged standard block detected by the spectrometer 11 is the absorption peak wavelength of the first medium;

[0043] ② The self-calibration control module sets λ 11 Written into the wavelength positioning formula of the measurement control module for detecting the light intensity of the first medium.

[0044] Optionally, the self-calibration control module calculates the wavelength deviation to be calibrated and sends it to the measurement control module for wavelength positioning calibration, which is the wavelength positioning calibration of the second medium for light intensity calculation, including:

[0045] ① The self-calibration control module reads the wavelength λ of the absorption peak in the packaged standard block detected by the spectrometer 11 is the absorption peak wavelength of the first medium;

[0046] ② The self-calibration control module calculates the theoretical wavelength difference of the second medium, △λ 21=λ2-λ1, where λ1 is the theoretical wavelength of the package medium in the package standard block, i.e., the first medium, and λ2 is the theoretical wavelength of the second medium;

[0047] ③ The self-calibration control module calculates the detection positioning wavelength of the second medium according to the theoretical wavelength difference, λ 22 =△λ 21 +λ 11 ;

[0048] ④Self-calibration control module 22 Write it into the wavelength positioning formula for calculating the light intensity of the second medium detected by the measurement control module.

[0049] Furthermore, the measurement control module performs wavelength positioning calibration, further comprising:

[0050] ① The self-calibration control module calculates the calibration pressure P0 of the package standard block. Among them, P b is the pressure when encapsulating the standard block, T b T0 is the temperature of the package standard block when it is packaged, and T1 is the temperature of the package standard block when it is calibrated;

[0051] ② The self-calibration control module transmits the calibration pressure P0 of the package standard block and the temperature T0 inside the analyzer shell to the measurement control module. The measurement control module performs wavelength positioning calibration based on the corresponding formula between the central wavelength and pressure and temperature.

[0052] The calibration method and calibration device provided by the present invention can calibrate the wavelength and light intensity of the spectrum analyzer online, and regularly verify the accuracy of the calibration program, thereby ensuring the accuracy of the calibration and improving the measurement accuracy of the analyzer; the calibration device integrates the light blocking sheet, the light blocking sheet group and the standard block group, has a simple structure and reliable operation, and can cooperate with the calibration algorithm to provide more reference data for the calibration algorithm, thereby further improving the calibration accuracy; there is no need for maintenance personnel to perform manual calibration, and interference from human factors can be completely avoided. Objective and fair monitoring of pollutant emissions can be achieved, reducing costs, and the device can be widely used in the field of environmental protection testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the structure provided by the first embodiment of the present invention;

[0054] Figure 2 Schematic diagram of the structure of the calibration sheet in Example 1;

[0055] Figure 3 A structural diagram of the second embodiment of the present invention;

[0056] Figure 4A schematic diagram of the structure of the third embodiment of the present invention;

[0057] Figure 5 Schematic diagram of the structure of the calibration sheet in Example 3;

[0058] Figure 6 A schematic diagram of the structure of the fourth embodiment of the present invention;

[0059] Figure 7 Schematic diagram of the structure of the calibration sheet in Example 4;

[0060] In the figure: 1. Analyzer housing; 2. Measurement control module; 3. Measuring cell; 4. Spectrometer; 5. Light source; 6. Self-calibration control module; 7. Driving mechanism; 71. First driving mechanism; 72. Second driving mechanism; 7.1. Crank arm; 7.2. Driving shaft; 8. Calibration plate; 81. First calibration plate; 82. Second calibration plate; 8.1. Light blocking plate; 8.2. Light blocking plate group; 8.3 Packaged calibration block group; 9. Transparent mirror; 10. Reflecting mirror; 11. Inlet pipe; 12. Zero gas pipe; 13. Temperature sensor. DETAILED DESCRIPTION

[0061] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0062] Example 1

[0063] like Figure 1 As shown, a self-calibration and self-verification device for an optical spectrum analyzer includes an analyzer housing 1, a measurement control module 2 of the analyzer, a measuring cell 3, a spectrometer 4 and a light source 5. The measuring cell 3 is arranged on one side of the analyzer housing 1, and the light source 5 is arranged on a side of the analyzer housing 1 away from the measuring cell 3. Light emitted by the light source 5 enters the spectrometer 4 after passing through the measuring cell 3. A light-transmitting mirror 9 is provided on the side of the measuring cell 3 close to the analyzer housing 1, and a reflector 10 is provided on the other side of the measuring cell 3 and at a position corresponding to the light-transmitting mirror 9. The spectrometer 4 is arranged on the side of the analyzer housing 1 away from the measuring cell 3. The measurement control module 2 is signal-connected to the light source 5 and the spectrometer 4 respectively; the self-calibration control module 6 is also included, as well as a drive mechanism 7 and a calibration plate 8 arranged in the analyzer housing 1. The calibration plate 8 includes a light-blocking plate 8.1, a light-blocking plate group 8.2, and a packaged calibration block group 8.3. The self-calibration control module 6 is signal-connected to the drive mechanism 7, the spectrometer 4, and the measurement control module 2 respectively; the drive mechanism 7 drives the calibration plate 8 to move to different positions, including:

[0064] First position: the center of the light shield 8.1 is located in the light path from the light source 5 to the measuring cell 3;

[0065] Second position: the centers of the light-blocking sheets of the light-blocking sheet set 8.2 are located in the optical path from the light source 5 to the measuring cell 3;

[0066] The third position: the center of each packaged calibration block of the packaged calibration block group 8.3 is located in the optical path from the light source 5 to the measuring cell 3;

[0067] In the fourth position, the light blocking sheet 8.1, the light blocking sheet set 8.2, and the packaged calibration block set 8.3 are all removed from the light path;

[0068] The transmittance of the light-blocking plate 8.1 is 0; in this embodiment, the light-blocking plate group 8.2 includes 1 light-blocking plate, and the transmittance of the light-blocking plate is a1, a1<1; the packaged calibration block group 8.3 includes 1 packaged calibration block, and the packaged standard block is a sealed container with lenses on both sides, and a medium sample of standard concentration is packaged inside the container; or, an optical filter is provided in the packaged standard block, and the spectral absorption wavelength of the optical filter is the same as the absorption wavelength of the medium sample of standard concentration.

[0069] An air inlet pipe 11 and a zero gas pipe 12 are provided on the measuring cell 3. The air inlet pipe 11 is used to introduce the gas to be measured, and the zero gas pipe 12 is used to introduce gas with zero medium concentration.

[0070] The driving mechanism 7 includes a driving device and a movable arm. The movable arm is connected to the calibration plate 8. The light-blocking plate, the light-blocking plate, and the packaged calibration block in the calibration plate 8 are connected in sequence up and down.

[0071] The driving device is a driving motor.

[0072] A timing calibration program can be set in the self-calibration control module 6. The self-calibration control module 6 controls the driving device to start, drives the calibration piece 8 to move to the third position, and the spectral signal measured by the spectrometer 4 is sent to the measurement control module. The measurement control module 2 sends the measured spectral wavelength value to the self-calibration control module 6 through the spectrometer 4. The self-calibration control module 6 calculates the wavelength value to be calibrated and sends it to the measurement control module 2 for wavelength calibration; after the wavelength calibration is completed, the self-calibration control module 6 controls the driving device to drive the calibration piece 8 to move to the first position, and the spectral signal measured by the spectrometer 4 is sent to the measurement control module 2. The measurement control module 2 sends the spectral light intensity value to the self-calibration control module 6. The self-calibration control module 6 controls the driving device to drive the calibration piece 8 to move to the second position, and the spectral signal measured by the spectrometer 4 is sent to the measurement control module 2. The measurement control module 2 sends the spectral light intensity value to the self-calibration control module 6. It is sent to the self-calibration control module 6, and the self-calibration control module 6 calculates the light intensity value to be calibrated and sends it to the measurement control module 2 for spectral intensity linear calibration; after the wavelength calibration and spectral intensity linear calibration are completed, the self-calibration control module 6 controls the driving device to drive the calibration plate 8 to move to the fourth position, and the light blocking plate 8.1, the light blocking plate group 8.2, and the packaged calibration block group 8.3 all withdraw from the optical path; a timed calibration accuracy self-verification program can be set in the self-calibration control module 6, and the self-calibration control module 6 controls the driving device to start, driving the calibration plate 8 to move to the third position, and the spectral signal measured by the spectrometer 4 is sent to the measurement control module 2, and the measurement control module 2 sends the detected gas concentration value to the self-calibration control module 6, and the self-calibration control module 6 compares the detected gas concentration value with the nominal concentration value of the packaged calibration block medium sample to determine whether it exceeds the allowable measurement error value.

[0073] Specifically, a method for performing self-calibration using the self-calibration and self-verification device of the optical spectrum analyzer in the above embodiment includes the following steps:

[0074] The first step is to start the wavelength positioning calibration. The calibration procedure is as follows:

[0075] ① Pass the medium sample with zero concentration into the measuring cell 3 and fill it up;

[0076] ② The self-calibration control module 6 controls the driving mechanism 7 to drive the calibration piece 8 to move so that the center of the packaged standard block is positioned at the center of the optical path. The measurement control module 2 reads the currently measured wavelength value λ through the spectrometer 4. 11 As the wavelength value of the first medium, and sent to the self-calibration control module 6;

[0077] ③ The self-calibration control module 6 calculates the theoretical wavelength difference, △λ 21 =λ2-λ1, where λ1 is the theoretical wavelength of the package medium in the package standard block, i.e., the first medium, and λ2 is the theoretical wavelength of the second medium;

[0078] ④ The self-calibration control module 6 calculates the detection positioning wavelength of the second medium according to the theoretical wavelength difference, λ 22 =△λ 21 +λ 11 , where λ 11 The wavelength value obtained after the light emitted by the light source in step ② passes through the encapsulated standard block;

[0079] ⑤ The self-calibration control module 6 sets the detection positioning wavelength λ of the second medium 22 Transmitted to the measurement control module 2, the measurement control module 2 performs wavelength positioning calibration on the second medium according to a preset wavelength positioning algorithm;

[0080] ⑥ After the wavelength positioning calibration is completed, the self-calibration control module 6 controls the driving mechanism 7 to move the calibration piece 8, so that the light blocking piece 8.1, the light blocking piece group 8.2, and the packaged calibration block group 8.3 are all withdrawn from the light path;

[0081] Step 2: Start the spectral intensity linear calibration. The calibration procedure is as follows:

[0082] ① The self-calibration control module 6 controls the driving mechanism 7 to move the calibration plate 8 so that the center of the light shield 8.1 is positioned at the center of the optical path. The self-measurement control module 2 reads the light intensity signal K0 through the spectrometer 4 and sends it to the self-calibration control module 6;

[0083] ② Pass the medium sample with zero concentration into the measuring cell 3 and fill it up;

[0084] ③ The self-calibration control module 6 controls the driving mechanism 7 to drive the calibration piece 8 to move, so that the light blocking piece 8.1, the light blocking piece group 8.2, and the packaged calibration block group 8.3 are all removed from the light path. The measurement control module 2 reads the light intensity signal K through the spectrometer 4 100 And send it to the self-calibration control module 6;

[0085] ④ The self-calibration control module 6 controls the driving mechanism 7 to move the calibration plate 8 and positions the center of the light-blocking plate at the center of the optical path. The measurement control module 2 reads the current light intensity signal K1 through the spectrometer 4 and sends it to the self-calibration control module 6;

[0086] ⑤ The self-calibration control module 6 writes the measurement results of ①③④ into the preset function of the measurement control module 2 at the same time. The measurement control module 2 performs spectral intensity linear calibration according to the prefabricated transmittance of each light-blocking plate and the current light intensity signal:

[0087] X0=K0 / K 100 ,Y0=0

[0088] X1=K1 / K 100 ,Y1=a1

[0089] X100 =1Y 100 =1, the prefabricated transmittance of the light-blocking plate is a1;

[0090] ⑥ After the spectral intensity linear calibration is completed, the self-calibration control module 6 controls the driving mechanism 7 to move the calibration plate 8, so that the light blocking plate 8.1, the light blocking plate group 8.2, and the packaged calibration block group 8.3 all withdraw from the light path.

[0091] Step 3: Start the calibration accuracy self-verification. The verification procedure is as follows:

[0092] ① Pass the medium sample with zero concentration into the measuring cell 3 and fill it up;

[0093] ② The self-calibration control module 6 controls the driving mechanism 7 to move the calibration piece 8 so that the center of the packaged standard block in the packaged calibration block group 8.3 is positioned at the center of the optical path. The self-calibration control module 6 sequentially reads the gas concentration value C1 detected by the measurement control module 2;

[0094] ③ Compare the nominal indication C0 of the analyzer after the packaged calibration block is inserted into the optical path with the gas concentration value detected in step ②; the nominal indication of the analyzer after the packaged calibration block is inserted into the optical path is calculated as follows:

[0095]

[0096] L2 is the length of the medium sample in the packaged calibration block, L1 is the length in the measuring cell, and this embodiment adopts a single reflection type measuring cell. The optical path through the measuring cell is 2L1, C b is the nominal concentration value of the medium sample in the packaged calibration block, and C0 is the nominal value of the medium sample in the packaged calibration block converted to the detection concentration of the analyzer;

[0097] ④When ABS(C1-C0)>C 11 When the self-calibration control module issues a self-calibration out-of-tolerance fault alarm, requesting maintenance;

[0098] When ABS(C1-C0)≤C 11 When , the spectrum analyzer's self-calibration procedure runs normally;

[0099] Among them, C 11 The self-calibration allowable measurement error value preset for the analyzer;

[0100] ⑤ After the calibration accuracy self-verification program is completed, the self-calibration control module 6 controls the driving mechanism 7 to move the calibration plate 8, so that the light blocking plate 8.1, the light blocking plate group 8.2, and the packaged calibration block group 8.3 all withdraw from the light path.

[0101] Example 2

[0102] like Figure 3As shown, this embodiment differs from the first embodiment in that light-transmitting mirrors 9 are provided on both sides of the measuring cell 3, and the spectrometer 4 is disposed on the outside of the measuring cell 3, away from the analyzer housing 1. The drive device is a pneumatic device with an air source. The self-calibration control module 6 and the measurement control module 2 are integrated into a single control element.

[0103] The self-calibration and self-verification method of the spectrum analyzer in this embodiment differs from that in the first embodiment in that step ③ in the third step is as follows:

[0104] Compare the nominal indication C0 of the analyzer after the packaged calibration block is inserted into the optical path with the gas concentration value detected in step ②. The nominal indication C0 of the analyzer after the packaged calibration block is inserted into the optical path is calculated as follows:

[0105]

[0106] L2 is the length of the medium sample in the packaged calibration block, L1 is the length in the measuring cell, and this embodiment is a single-path through-type measuring cell. The optical path through the measuring cell is L1, C b is the nominal concentration value of the medium sample in the packaged calibration block, and C0 is the nominal value of the detection concentration of the medium sample in the packaged calibration block converted into the analyzer.

[0107] Example 3

[0108] like Figure 4 and Figure 5 As shown, the difference between this embodiment and the first embodiment is that the calibration sheet 8 includes a first calibration sheet 81 and a second calibration sheet 82. The first calibration sheet 81 is provided with a light-blocking sheet 8.1 and a packaged calibration block group 8.3 connected in sequence. The packaged calibration block group 8.3 includes one packaged calibration block. The second calibration sheet 82 is provided with a light-blocking sheet group 8.2. The light-blocking sheet group 8.2 includes a first light-blocking sheet and a second light-blocking sheet arranged in sequence above and below. The transmittance of the first light-blocking sheet is a1, and the transmittance of the second light-blocking sheet is a2. The drive mechanism 7 includes a first drive mechanism 71 and a second drive mechanism 72. The first drive mechanism 71 is connected to the first calibration sheet 81, and the second drive mechanism 72 is connected to the second calibration sheet 82. A temperature sensor 13 is also provided in the analyzer housing. The temperature sensor 13 sends a temperature signal T0 to the self-calibration control module, and the temperature in the analyzer housing is used to represent the temperature T0 in the package module.

[0109] The first driving mechanism 71 drives the first calibration plate 81 to move to different positions, including:

[0110] First position: the center of the light shield 8.1 is located in the light path from the light source 5 to the measuring cell 3;

[0111] Second position: the center of the packaged calibration block is located in the optical path from the light source 5 to the measuring cell 3;

[0112] In the third position, the light shield 8.1 and the packaged calibration block are all removed from the light path.

[0113] The second driving mechanism 72 drives the second calibration plate 82 to move to different positions, including:

[0114] First position: the center of the first light barrier is located in the light path from the light source 5 to the measuring cell 3;

[0115] Second position: the center of the second light-blocking plate is located in the optical path from the light source 5 to the measuring cell 3;

[0116] In the third position, the first light-blocking plate and the second light-blocking plate are completely withdrawn from the light path.

[0117] The self-calibration and self-verification method of the spectrum analyzer in this embodiment differs from that in the first embodiment in that the following steps are further included between steps ④ and ⑤ of the first step:

[0118] The self-calibration control module calculates the calibration pressure P0 of the package standard block. Among them, P b is the pressure when encapsulating the standard block, T b is the temperature when the standard block is packaged, and T0 is the temperature inside the analyzer housing;

[0119] The self-calibration control module will calibrate the pressure P0 of the packaged standard block, the temperature T0 inside the analyzer housing, and the detection positioning wavelength λ 22 The data is transmitted to the measurement control module, which performs wavelength positioning calibration on the gas to be detected based on the corresponding formula between the central wavelength and pressure and temperature;

[0120] Steps 4 and 5 of the second step are as follows:

[0121] ④ The self-calibration control module controls the first driving mechanism 71 to drive the first calibration piece 81 to move to the third position;

[0122] The self-calibration control module controls the second driving mechanism 72 to drive the second calibration plate 82 to move to the first position and the second position in sequence, so that the centers of the first light-blocking plate and the second light-blocking plate are positioned at the center of the optical path in sequence. The measurement control module reads the current light intensity signals K1 and K2 respectively through the spectrometer and sends them to the self-calibration control module;

[0123] The self-calibration control module controls the second driving mechanism 72 to drive the second calibration piece 82 to move to the third position;

[0124] ⑤ The self-calibration control module writes the measurement results of ①③④ into the preset function of the measurement control module at the same time. The measurement control module performs spectral intensity linear calibration based on the preset transmittance of each light blocker and the current light intensity signal:

[0125] X0=K0 / K 100,Y0=0

[0126] X1=K1 / K 100 ,Y1=a1

[0127] X2=K2K 100 ,Y2=a2

[0128] X 100 =1Y 100 =1, the prefabricated light transmittance of the first light-blocking plate is a1, and the prefabricated light transmittance of the second light-blocking plate is a2.

[0129] Example 4

[0130] like Figure 6 and Figure 7 As shown, the difference between this embodiment and embodiment 1 is that the driving mechanism 7 includes a driving device and a crank arm 7.1, the crank arm is connected to the calibration plate 8, and the light blocking plate 8.1, the light blocking plate group 8.2, and the packaged calibration block group 8.3 in the calibration plate 8 are arranged in sequence on an arc centered on the driving shaft 7.2 of the driving device; the light source 5 is a laser light source.

[0131] The drive device drives the calibration plate 8 to rotate around the drive shaft 7.2 to different positions through the crank arm 7.1, including:

[0132] First position: the center of the light shield 8.1 is located in the light path from the light source 5 to the measuring cell 3;

[0133] Second position: the centers of the light-blocking sheets of the light-blocking sheet set 8.2 are located in the optical path from the light source 5 to the measuring cell 3;

[0134] The third position: the center of each packaged calibration block of the packaged calibration block group 8.3 is located in the optical path from the light source 5 to the measuring cell 3;

[0135] In the fourth position, the light blocking sheet 8.1, the light blocking sheet set 8.2, and the packaged calibration block set 8.3 are all removed from the light path;

[0136] The self-calibration and self-verification method of the spectrum analyzer in this embodiment differs from that in the first embodiment in that steps ③, ④, and ⑤ of the first step are specifically as follows:

[0137] ③ The self-calibration control module calculates the wavelength difference, △λ=λ 00 -λ 01 , where λ 00 is the central wavelength of the light emitted by the light source, λ 01 The central wavelength value of the absorption peak of the light emitted by the light source after passing through the encapsulated standard block;

[0138] ④ The self-calibration control module transmits the wavelength difference to the measurement control module, which adjusts the central wavelength of the light emitted by the light source to λ according to the wavelength difference. 01.

[0139] The linearity of the spectrometer's detection at different brightness levels affects the test results. The wavelength drift after long-term operation will affect the test results. After the spectrometer's spectral frequency (wavelength) is calibrated, the accuracy of the analyzer can be guaranteed as long as the linearity of the spectrometer's brightness detection is guaranteed. Therefore, after the detection spectrum wavelength (frequency) is calibrated, the linearity of the spectrometer's brightness detection is calibrated. If the linearity meets the requirements, the analyzer's test results will not exceed the tolerance.

[0140] The calibration method provided by the present invention can calibrate the spectrum and light intensity of the analyzer online through the provided calibration device, and regularly verify the accuracy of the calibration program, without the need for maintenance personnel to perform manual calibration and calibration; the calibration device integrates the light blocking sheet, the light blocking sheet group and the standard block group, has a simple structure and reliable operation, and can cooperate with the calibration algorithm to provide more reference data for the calibration algorithm, thereby improving the calibration accuracy; this device and method can calibrate the light source and the medium to be measured, and can completely avoid the interference of human factors, realize objective and fair monitoring of pollutant emissions, reduce costs, and can be widely used in the field of environmental protection detection.

[0141] In the various embodiments of the present application, gas is mainly used as the medium for calibration, and the calibration of a spectrum analyzer using liquid as the medium is also applicable.

[0142] In the description of the present invention, it should be understood that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0143] In the present invention, unless otherwise clearly specified and limited, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be internal communication between two elements or an interaction relationship between two elements. Unless otherwise clearly specified and limited, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0144] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A self-calibration and self-verification method for an optical spectrum analyzer, utilizing a self-calibration and self-verification device for the optical spectrum analyzer. The device comprises an analyzer housing, a measurement control module of the analyzer, a measuring cell, a spectrometer, and a light source. The measuring cell is disposed on one side of the analyzer housing, and the light source is disposed on a side of the analyzer housing away from the measuring cell. Light emitted by the light source passes through the measuring cell and enters the spectrometer. The measurement control module is signal-connected to the light source and the spectrometer, respectively. The method also includes a self-calibration control module, a drive mechanism and a calibration plate disposed within the analyzer housing. The calibration plate comprises a light-blocking plate, a light-blocking plate group, and a packaged calibration block group. The self-calibration control module is signal-connected to the drive mechanism, the spectrometer, and the measurement control module, respectively. The drive mechanism drives the calibration plate to move to different positions, comprising: The center of the light blocking sheet is located in the optical path from the light source to the measuring cell. The centers of the light blocking sheets in the light blocking sheet group are respectively located in the optical path from the light source to the measuring cell. The centers of the packaged calibration blocks in the packaged calibration block group are respectively located in the optical path from the light source to the measuring cell. The light blocking sheet, the light blocking sheet group, and the packaged calibration block group are all removed from the optical path. The light-blocking sheet has a light transmittance of 0; the light-blocking sheet group includes m light-blocking sheets, and the prefabricated light transmittances of the light-blocking sheets are a_1, a_2, ..., a_m, where m≥1; the packaged calibration block group includes n packaged calibration blocks, where n≥1; Characterized in that the method comprises the following steps: The first step is to start the wavelength positioning calibration. The calibration procedure is as follows: Pass the medium sample with zero concentration into the measuring cell and fill it up; The self-calibration control module controls the driving mechanism to move the calibration piece so that the center of any packaged standard block is positioned at the center of the optical path. The measurement control module reads the current measured wavelength value through the spectrometer and sends it to the self-calibration control module; The self-calibration control module calculates the wavelength deviation to be calibrated and sends it to the measurement control module for wavelength positioning calibration, wherein the wavelength positioning calibration step includes: The self-calibration control module reads the absorption peak wavelength in the packaged standard block detected by the spectrometer is the absorption peak wavelength of the first medium; The self-calibration control module calculates the theoretical wavelength difference of the second medium, △ = ,in, is the theoretical wavelength value of the package medium in the package standard block, that is, the first medium, is the theoretical wavelength value of the second medium; The self-calibration control module calculates the detection positioning wavelength of the second medium based on the theoretical wavelength difference. =△ + ; Self-calibration control module Writing into the wavelength positioning formula of the measurement control module for detecting the light intensity of the second medium; ④ After the wavelength positioning calibration is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path; Step 2: Start the spectral intensity linear calibration. The calibration procedure is as follows: The self-calibration control module controls the driving mechanism to move the calibration piece so that the center of the light-blocking piece is positioned at the center of the optical path. The self-measurement control module reads the light intensity signal through the spectrometer. And send it to the self-calibration control module; Pass the medium sample with zero concentration into the measuring cell and fill it up; The self-calibration control module controls the driving mechanism to move the calibration piece so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path. The measurement control module reads the light intensity signal through the spectrometer. And send it to the self-calibration control module; The self-calibration control module controls the driving mechanism to move the calibration piece and positions the center of each light-blocking piece in the light-blocking piece group at the center of the optical path in turn. The measurement control module reads the current light intensity signal through the spectrometer. 、 … And send it to the self-calibration control module; The self-calibration control module will The measurement results are written into the preset function of the measurement control module at the same time. The measurement control module performs spectral intensity linear calibration according to the preset transmittance of each light blocker and the current light intensity signal: …… , where the prefabricated transmittances of each light-blocking sheet in the light-blocking sheet group are , … ; After the spectral intensity linear calibration is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path.

2. The self-calibration and self-verification method of an optical spectrum analyzer according to claim 1, wherein: Also included is a calibration accuracy self-verification procedure, which includes the following steps: Pass the medium sample with zero concentration into the measuring cell and fill it up; The self-calibration control module controls the driving mechanism to move the calibration piece so that the center of each packaged standard block in the packaged calibration block group is positioned in the center of the optical path in turn. The self-calibration control module reads the medium concentration value detected by the measurement control module in turn. 、 … ; The nominal value of the analyzer after the packaged calibration block is inserted into the optical path Compare the result with the medium concentration value detected in step ②. When the difference between the two is greater than the allowable measurement error value, the self-calibration control module will issue a fault alarm. After the self-calibration accuracy self-verification program is completed, the self-calibration control module controls the driving mechanism to move the calibration piece, so that the light blocking piece, the light blocking piece group, and the packaged calibration block group all withdraw from the light path.

3. The self-calibration and self-verification method of an optical spectrum analyzer according to claim 2, wherein: The nominal indication of the analyzer after the packaged calibration block is inserted into the optical path is calculated as follows: ,in, is the length of the dielectric sample in the nth package calibration block, Measure the length inside the pool, is the number of times the light passes through the measuring cell, is the nominal concentration value of the nth packaged calibration block medium sample, The nominal value of the detection concentration of the analyzer converted from the medium sample in the nth packaged calibration block; When ABS( When the self-calibration control module issues a self-calibration out-of-tolerance fault alarm, requesting maintenance; When ABS( ≤ When , the spectrum analyzer's self-calibration procedure runs normally; in, The allowable measurement error value of the analyzer self-calibration.

4. The self-calibration and self-verification method of an optical spectrum analyzer according to claim 1, wherein: The packaged standard block is a sealed container with lenses on both sides, and a medium sample of standard concentration is packaged inside the container; alternatively, an optical filter is provided inside the packaged standard block, and the spectral absorption wavelength of the optical filter is the same as the absorption wavelength of the medium sample of standard concentration.

5. The self-calibration and self-verification method of an optical spectrum analyzer according to claim 4, characterized in that: The driving mechanism includes a driving device and a movable arm, the movable arm is connected to the calibration plate, and the light-blocking plate, the light-blocking plate group, and the packaged calibration block group in the calibration plate are connected in sequence up and down; or, the driving mechanism includes a first driving mechanism and a second driving mechanism, the calibration plate includes a first calibration plate and a second calibration plate, the first driving mechanism is connected to the first calibration plate, the second driving mechanism is connected to the second calibration plate, the first calibration plate includes a light-blocking plate and a packaged calibration block group, and the light-blocking plate and the packaged calibration block group are connected in sequence up and down, the second calibration plate includes a light-blocking plate group, and each light-blocking plate in the light-blocking plate group is connected in sequence up and down; or, the driving mechanism includes a driving device and a crank arm, the crank arm is connected to the calibration plate, the light-blocking plate, the light-blocking plate group, and the packaged calibration block group in the calibration plate are arranged in sequence on an arc centered on the driving axis of the driving device.

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