Efficient optical path self-calibration ozone high-frequency measurement system and method

Abstract

The invention discloses an effective optical path self-calibration ozone high-frequency measurement system and method, and relates to the technical field of atmospheric environment monitoring and high-precision cavities. Sampling gas or ozone gas with standard concentration is input into a high-precision cavity measurement module; the sampling gas is ambient atmosphere or ambient atmosphere after ozone filtration; the modulation circuit generates a square wave signal to modulate the light source; the high-precision cavity module is used for measuring sampling gas or ozone gas with standard concentration and inputting a result into the signal processing module. The signal processing module can measure the ozone concentration and calculate and calibrate the effective optical path. The measurement system and method can realize real-time calculation and calibration of the effective optical path so as to accurately measure the ozone concentration.

Description

Technical Field

[0001] This invention relates to the field of atmospheric environment monitoring and high-precision cavity technology, and in particular to an effective optical path self-calibration ozone high-frequency measurement system and method. Background Technology

[0002] Ozone, as an air pollutant, is a key and challenging aspect of air pollution control. Ozone formation is primarily influenced by local photochemical reactions and physical transport, and simple point-based concentration measurements are no longer sufficient for ozone pollution control. Real-time, long-term, and accurate monitoring of ozone flux is crucial for studying ozone formation and pollution control; however, flux measurement places high demands on instrument sensitivity and temporal resolution. This invention utilizes high-precision cavity technology based on ultraviolet absorption to achieve high-sensitivity and high-frequency ozone measurement. Currently, high-precision cavity technology suffers from problems such as susceptibility to cavity pressure and noise interference. Changes in ambient air pressure or sampling flow rate can alter cavity pressure, causing continuous variations in the system's effective optical path. Furthermore, the LED light source used in ultraviolet absorption has a broad spectral line; in heavily polluted areas, measurement results are easily affected by substances such as formaldehyde and aromatic hydrocarbons, further leading to significant deviations in ozone measurement results. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides an effective optical path self-calibration ozone high-frequency measurement system and method.

[0004] To achieve the above objectives, the present invention adopts the following technical solution, including:

[0005] An effective optical path self-calibrated ozone high-frequency measurement system includes: an air intake module, a high-precision cavity module, and a signal processing module;

[0006] The air intake module is connected to the high-precision cavity module and is used to introduce ambient air into the cavity of the high-precision cavity module, or to introduce ambient air after ozone removal.

[0007] In the high-precision cavity measurement module, the light source emits broadband light in the absorption band of the gas to be measured, which is then modulated by a square wave by a modulation circuit. The modulated broadband light enters the cavity after passing through a collimating lens and an aperture. After multiple reflections by the first and second high-reflection mirrors at both ends of the cavity, the broadband light is output. After passing through a filter, a focusing lens, and a photomultiplier tube, the measured absorption signal is sent to the signal processing module.

[0008] The signal processing module is used to extract harmonic signals based on piecewise fast Fourier transform and calculate the ozone gas absorption coefficient, as follows:

[0009] Using a square wave signal with the same frequency and phase as the pulse signal as the reference signal; sampling the absorption signal at the rising edge of the square wave signal, and obtaining a complete cycle of absorption signal after sampling; dividing the sampled complete cycle of absorption signal into multiple segments; performing a fast Fourier transform on each segment of absorption signal to obtain the amplitude of the harmonic signal within each segment; after processing the signal of the entire cycle, the complete harmonic signal amplitude can be obtained.

[0010] The absorption coefficient of the gas to be measured, i.e., ozone gas, is calculated based on the harmonic signal amplitudes during background measurement and ozone absorption.

[0011] The absorption coefficient α of ozone gas is:

[0012]

[0013] Where V0 is the harmonic signal amplitude when measuring the background, V is the harmonic signal amplitude when ozone is absorbed, and α Ray L is the Rayleigh scattering extinction coefficient. eff The effective optical path length; the measurement background refers to the ambient atmosphere after ozone removal being introduced into the cavity of the high-precision cavity module; the ozone absorption refers to the ambient atmosphere being introduced into the cavity of the high-precision cavity module.

[0014] The signal processing module achieves the effective optical path L by fitting the ringing time τ0 when measuring the background. eff Calculation of L: eff =cτ0; where c is the speed of light.

[0015] Preferably, the high-frequency measurement system further includes: a standard ozone source module; the standard ozone source module is used to introduce ozone gas of a standard concentration into the cavity of the high-precision cavity module;

[0016] The signal processing module utilizes standard concentrations of ozone gas to process the effective optical path L. eff Calibration is performed as follows: The absorption coefficient of ozone gas is obtained based on the ozone concentration; the ring-down time τ0 and harmonic signal amplitude V0 at the background measurement are then obtained, along with the harmonic signal amplitude V at the standard ozone concentration. The standard effective optical path L is obtained using the formula for calculating the ozone gas absorption coefficient α. eff ';

[0017] The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Perform calibration.

[0018] Preferably, in the air intake module, ambient air enters from the input end of the air intake pipe, and the air intake pipe is equipped with a filter membrane for filtering out particulate matter in the ambient air. The output end of the air intake pipe is connected to two air paths through a No. 1 three-way solenoid valve. The first air path is equipped with a manganese dioxide pipe for filtering ozone in the ambient air. The second air path and the first air path are connected to the high-precision cavity module after being merged through a three-way connector.

[0019] Preferably, the standard ozone source module includes a standard ozone generator for generating standard concentration ozone and a flow meter for controlling the flow rate of standard ozone gas.

[0020] Preferably, the high-precision cavity measurement module further includes: a pressure gauge for real-time monitoring of the internal pressure of the cavity, an air pump for drawing gas into the cavity, and an air flow meter for controlling the pumping speed of the air pump.

[0021] In the high-precision cavity measurement module, an LED light source emits broadband light in the absorption band of the gas to be measured, which is then modulated by a modulation circuit using a square wave. A collimating lens converts the divergent light emitted by the LED light source into parallel light. An aperture filters out stray light from the edges of the parallel light output by the collimating lens and outputs the parallel light after filtering out stray light into the cavity. The light is then reflected multiple times by two high-reflection mirrors at both ends of the cavity before being output. A filter removes excess wavelengths from the broadband light output from the cavity. A focusing lens focuses the broadband light after filtering out excess wavelengths. A photomultiplier tube performs photoelectric conversion on the focused broadband light to obtain a photoelectric signal. This photoelectric signal is then sent to the signal processing module as the absorption signal obtained from the measurement.

[0022] This invention also provides a high-frequency ozone measurement method with effective optical path self-calibration, applied to the aforementioned high-frequency ozone measurement system with effective optical path self-calibration, comprising the following steps:

[0023] S11, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background.

[0024] S12, introduce ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal during ozone absorption; the signal processing module obtains the harmonic signal amplitude V during ozone absorption based on the absorption signal during ozone absorption.

[0025] S13, the signal processing module calculates the ozone gas absorption coefficient α and the ozone concentration C:

[0026]

[0027] The signal processing module achieves the effective optical path length L by fitting the ring-down time τ0 when measuring the background. eff Calculation of L: eff =cτ0.

[0028] Preferably, the signal processing module uses ozone gas of standard concentration to adjust the effective optical path L. eff The calibration process is as follows:

[0029] S21, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background.

[0030] S22, introduce ozone gas of standard concentration into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when ozone of standard concentration is absorbed; the signal processing module obtains the harmonic signal amplitude V when ozone of standard concentration is absorbed based on the absorption signal when ozone of standard concentration is absorbed.

[0031] S23, the signal processing module calculates the effective optical path L by fitting the ring-down time when measuring the background. eff Calculation of L: eff =cτ0;

[0032] The signal processing module also utilizes standard concentrations of ozone gas to measure the effective optical path L. eff Calibration is performed by first obtaining the ozone gas absorption coefficient α based on the ozone concentration; then, using the formula for calculating the ozone gas absorption coefficient α, the standard effective optical path L is derived. eff ';The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Perform calibration.

[0033] The present invention also provides a computer program product comprising a computer program / instructions that, when executed by a processor, implement the aforementioned effective optical path self-calibration ozone high-frequency measurement method.

[0034] The present invention also provides an electronic device, which includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for high-frequency ozone measurement with effective optical path self-calibration.

[0035] The advantages of this invention are:

[0036] (1) The system of the present invention can accurately measure the ozone gas absorption coefficient under different ambient air pressures or different sampling flow rates by pulse modulation of the light source and real-time calculation of the effective optical path of the system using the ring-down time.

[0037] (2) The system of the present invention combines the advantages of narrow bandwidth and low noise of modulation spectrum, and can realize ultra-sensitive detection of weak signals.

[0038] (3) The present invention uses the segmented fast Fourier transform (SFFT) algorithm to extract the harmonic amplitude of the absorption signal, thereby realizing the direct calculation of the ozone gas absorption coefficient and avoiding complex operations such as quadrature lock-in amplification.

[0039] (4) The present invention uses ozone gas of standard concentration to calibrate the effective optical path of the system and compares it with the calculation results to reduce the error of the calculation results.

[0040] (5) The system of the present invention uses manganese dioxide to filter ozone in the ambient atmosphere to measure the background, which improves the accuracy of the background measurement and reduces the interference of substances such as formaldehyde and aromatic hydrocarbons on the measurement results.

[0041] (6) The signal processing module of the present invention uses a high sampling rate acquisition card, and the air exchange speed of the air intake module and the standard ozone source module is fast. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of an effective optical path self-calibration ozone measurement system.

[0043] Figure 2 This is a schematic diagram of the piecewise fast Fourier transform.

[0044] The attached figures are labeled as follows:

[0045] Modulation circuit 1, LED light source 2, collimating lens 3, aperture 4, No. 1 high-reflection mirror 5, cavity 6, No. 2 high-reflection mirror 7, focusing lens 8, photomultiplier tube 9, signal processing module 10, standard ozone generator 11, filter 12, flow meter 13, No. 2 three-way solenoid valve 14, air pump 15, air extraction flow meter 16, pressure gauge 17, three-way connector 18, second air passage 19, manganese dioxide tube 20, No. 1 three-way solenoid valve 21, filter membrane 22. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] Depend on Figure 1 As shown, an effective optical path self-calibrated ozone high-frequency measurement system includes: an air intake module, a standard ozone source module, a high-precision cavity module, and a signal processing module 10.

[0049] In the air intake module, ambient air enters from the input end (i.e., sampling port) of the air intake pipe. The air intake pipe is equipped with a filter membrane 22 for filtering out particulate matter in the ambient air. The output end of the air intake pipe is connected to two air paths through a No. 1 three-way solenoid valve 21. The first air path is equipped with a manganese dioxide pipe 20 for filtering ozone in the ambient air. The second air path 19 and the first air path are merged through a three-way connector 18 and then connected to the high-precision cavity module through a No. 2 three-way solenoid valve 14.

[0050] The standard ozone source module includes a standard ozone generator 11 for generating standard concentration ozone and a flow meter 13 for controlling the flow rate of standard ozone gas. The standard ozone source module is also connected to the high-precision cavity module through a No. 2 three-way solenoid valve 14.

[0051] In the high-precision cavity measurement module, LED light source 2 emits broadband light in the absorption band of the gas to be measured, which is then modulated by a square wave by modulation circuit 1. Collimating lens 3 converts the divergent light emitted by LED light source 2 into parallel light. Aperture 4 filters out stray light from the edges of the parallel light output by collimating lens 3 and outputs the parallel light after filtering out stray light to Teflon cavity 6. High-reflection mirrors 5 and 7 are used to filter out multiple reflections of the input broadband light within the cavity. Filter 12 filters out excess bands of the broadband light (and ambient light) output from the cavity. Focusing lens 8 focuses the broadband light after filtering out excess bands. Photomultiplier tube 9 performs photoelectric conversion on the focused broadband light and obtains a photoelectric signal for real-time monitoring of the internal pressure of the cavity. Air pump 15 pumps gas into the cavity. Pump flow meter 16 controls the pumping speed of air pump 15. The photomultiplier tube 9 sends the collected photoelectric signal to signal processing module 10.

[0052] The signal processing module 10 is used to extract harmonic signals based on piecewise fast Fourier transform to calculate the ozone gas absorption coefficient, and to calculate and calibrate the effective optical path. The relevant principles are as follows:

[0053] (1) The absorption coefficient α of the ozone gas to be measured, i.e., ozone gas, is calculated based on the piecewise fast Fourier transform to extract the harmonic signal. The relationship between the absorption coefficient α and Rayleigh scattering and high mirror reflectivity is as follows:

[0054]

[0055] In the formula, I0 is the light intensity at the measurement background, which refers to the ambient atmosphere after ozone removal being introduced into the cavity of the high-precision cavity module; I is the light intensity attenuated due to ozone absorption, which refers to the ambient atmosphere or ozone gas of standard concentration being introduced into the cavity of the high-precision cavity module; R is the reflectivity of the high-reflectivity mirror; d is the distance between the two high-reflectivity mirrors; α Ray Here, is the Rayleigh scattering extinction coefficient; (1-R) / d is the theoretical cavity loss, and is the effective optical path length L. eff The reciprocal of, that is:

[0056]

[0057] After pulse modulation of the LED light source, the ring-down time τ0 when measuring the background has the following relationship with the high reflectivity R:

[0058]

[0059] Combining formulas (2) and (3), it can be seen that the effective optical path length L can be achieved by fitting the ring-down time τ0 when measuring the background. eff Real-time calculation, that is:

[0060]

[0061] The harmonic signal extraction process based on piecewise fast Fourier transform is as follows: Figure 2 As shown, the reference signal is a square wave signal with the same frequency and phase as the pulse signal. After capturing the rising edge of the square wave signal, sampling of the absorption signal begins. After sampling, a complete cycle of the absorption signal is obtained. The sampled complete cycle of the absorption signal is truncated, and after averaging the segments, a Fast Fourier Transform (FFT) is performed on each segment to obtain the amplitude of the harmonic signal within each segment. After processing the signal for the entire cycle, the complete harmonic signal amplitude can be obtained.

[0062] Therefore, formula (1) can be rewritten as:

[0063]

[0064] V0 is the harmonic signal amplitude when measuring the background, and V is the harmonic signal amplitude when absorbing ozone. The ozone concentration can be accurately measured according to formula (5).

[0065] α = N·σ, where N is the number density of ozone molecules and σ is the absorption cross section of ozone;

[0066] Based on the number density of ozone molecules (unit: molecule / cm³) 3 This is converted to obtain the ozone concentration (unit: ppb), 1 ppb = N2O.A / V m ×10 -9 molecule / cm 3 N A V is Avogadro's constant. m This represents the molar volume of the gas.

[0067] (2) Calculation and calibration of effective optical path

[0068] The effective optical path L can be achieved using the formulas (2)-(4) above. eff Calculation: The effective optical path length L is obtained by fitting the ring-down time τ0 when the background is measured. eff Calculation of L: eff =cτ0.

[0069] Using standard concentrations of ozone gas for effective optical path L eff Perform calibration:

[0070] Given the ozone concentration, the ozone absorption coefficient α can be obtained, along with the ring-down time τ0 and harmonic signal amplitude V0 at the background measurement, and the harmonic signal amplitude V at the standard concentration of ozone absorption. Based on the above formula (5), the standard effective optical path L can be calculated. eff ';

[0071] The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Calibration is performed to reduce errors in the calculation results.

[0072] Example 2

[0073] An effective optical path self-calibration method for high-frequency ozone measurement includes the following steps:

[0074] S11, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background.

[0075] S12, introduce ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal during ozone absorption; the signal processing module obtains the harmonic signal amplitude V during ozone absorption based on the absorption signal during ozone absorption.

[0076] S13, The signal processing module calculates the ozone gas absorption coefficient α:

[0077]

[0078] The signal processing module achieves the effective optical path length L by fitting the ring-down time τ0 when measuring the background. eff Calculation of L: eff =cτ0.

[0079] Example 3

[0080] Based on the ozone measurement in Example 2, the effective optical path L was measured using ozone gas of standard concentration. eff The calibration process is as follows:

[0081] S21, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background.

[0082] S22, introduce ozone gas of standard concentration into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when ozone of standard concentration is absorbed; the signal processing module obtains the harmonic signal amplitude V when ozone of standard concentration is absorbed based on the absorption signal when ozone of standard concentration is absorbed.

[0083] S23, the signal processing module calculates the effective optical path length L by fitting the ring-down time τ0 when measuring the background. eff Calculation of L: eff =cτ0;

[0084] The signal processing module also utilizes standard concentrations of ozone gas to measure the effective optical path L. eff Calibration is performed by first obtaining the ozone gas absorption coefficient α based on the ozone concentration; then, using the formula for calculating the ozone gas absorption coefficient α, the standard effective optical path L is derived. eff ';The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Perform calibration.

[0085] Subsequently, the ozone concentration was calculated using the calibrated effective optical path.

[0086] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-frequency ozone measurement system with effective optical path self-calibration, characterized in that, include: Intake module, high-precision cavity module, and signal processing module; The air intake module is connected to the high-precision cavity module and is used to introduce ambient air into the cavity of the high-precision cavity module, or to introduce ambient air after ozone removal. In the high-precision cavity measurement module, the light source emits broadband light in the absorption band of the gas to be measured, which is then modulated by a square wave by a modulation circuit. The modulated broadband light enters the cavity after passing through a collimating lens and an aperture. After multiple reflections by the first and second high-reflection mirrors at both ends of the cavity, the broadband light is output. After passing through a filter, a focusing lens, and a photomultiplier tube, the measured absorption signal is sent to the signal processing module. The signal processing module is used to extract harmonic signals based on piecewise fast Fourier transform and calculate the ozone gas absorption coefficient, as follows: Using a square wave signal with the same frequency and phase as the pulse signal as the reference signal; sampling the absorption signal at the rising edge of the square wave signal, and obtaining a complete cycle of absorption signal after sampling; dividing the sampled complete cycle of absorption signal into multiple segments; performing a fast Fourier transform on each segment of absorption signal to obtain the amplitude of the harmonic signal within each segment; after processing the signal of the entire cycle, the complete harmonic signal amplitude can be obtained. The absorption coefficient of the gas to be measured, i.e., ozone gas, is calculated based on the harmonic signal amplitudes during background measurement and ozone absorption. The absorption coefficient α of ozone gas is: Where V0 is the harmonic signal amplitude when measuring the background, V is the harmonic signal amplitude when ozone is absorbed, and α Ray L is the Rayleigh scattering extinction coefficient. eff The effective optical path length; the measurement background refers to the ambient atmosphere after ozone removal being introduced into the cavity of the high-precision cavity module; the ozone absorption refers to the ambient atmosphere being introduced into the cavity of the high-precision cavity module. The signal processing module achieves the effective optical path L by fitting the ringing time τ0 when measuring the background. eff Calculation of L: eff =cτ0; where c is the speed of light.

2. The ozone high-frequency measurement system with effective optical path self-calibration according to claim 1, characterized in that, The high-frequency measurement system further includes: a standard ozone source module; the standard ozone source module is used to introduce ozone gas of a standard concentration into the cavity of the high-precision cavity module; The signal processing module utilizes standard concentrations of ozone gas to process the effective optical path L. eff Calibration is performed as follows: The absorption coefficient of ozone gas is obtained based on the ozone concentration; the ring-down time τ0 and harmonic signal amplitude V0 at the background measurement are then obtained, along with the harmonic signal amplitude V at the standard ozone concentration. The standard effective optical path L is obtained using the formula for calculating the ozone gas absorption coefficient α. eff '; The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Perform calibration.

3. The ozone high-frequency measurement system with effective optical path self-calibration according to claim 1, characterized in that, In the intake module, ambient air enters from the input end of the intake pipe. The intake pipe is equipped with a filter membrane for filtering out particulate matter in the ambient air. The output end of the intake pipe is connected to two air paths through a No. 1 three-way solenoid valve. The first air path is equipped with a manganese dioxide pipe for filtering ozone in the ambient air. The second air path and the first air path are connected to the high-precision cavity module after being merged through a three-way connector.

4. The ozone high-frequency measurement system with effective optical path self-calibration according to claim 2, characterized in that, The standard ozone source module includes a standard ozone generator for generating standard concentration ozone and a flow meter for controlling the flow rate of standard ozone gas.

5. The ozone high-frequency measurement system with effective optical path self-calibration according to claim 1, characterized in that, The high-precision cavity measurement module also includes: a pressure gauge for real-time monitoring of the internal pressure of the cavity, an air pump for drawing gas into the cavity, and an air flow meter for controlling the pumping speed of the air pump. In the high-precision cavity measurement module, an LED light source emits broadband light in the absorption band of the gas to be measured, which is then modulated by a modulation circuit using a square wave. A collimating lens converts the divergent light emitted by the LED light source into parallel light. An aperture filters out stray light from the edges of the parallel light output by the collimating lens and outputs the parallel light after filtering out stray light into the cavity. The light is then reflected multiple times by two high-reflection mirrors at both ends of the cavity before being output. A filter removes excess wavelengths from the broadband light output from the cavity. A focusing lens focuses the broadband light after filtering out excess wavelengths. A photomultiplier tube performs photoelectric conversion on the focused broadband light to obtain a photoelectric signal. This photoelectric signal is then sent to the signal processing module as the absorption signal obtained from the measurement.

6. A high-frequency ozone measurement method with effective optical path self-calibration, characterized in that, An ozone high-frequency measurement system with effective optical path self-calibration as described in any one of claims 1-5 includes the following steps: S11, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background. S12, introduce ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal during ozone absorption; the signal processing module obtains the harmonic signal amplitude V during ozone absorption based on the absorption signal during ozone absorption. S13, The signal processing module calculates the ozone gas absorption coefficient α: The signal processing module achieves the effective optical path length L by fitting the ring-down time τ0 when measuring the background. eff Calculation of L: eff =cτ0.

7. The ozone high-frequency measurement method with effective optical path self-calibration according to claim 6, characterized in that, The signal processing module uses standard concentrations of ozone gas to measure the effective optical path L. eff The calibration process is as follows: S21, introduce ozone-filtered ambient air into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when measuring the background; the signal processing module obtains the decay time τ0 and harmonic signal amplitude V0 when measuring the background based on the absorption signal when measuring the background. S22, introduce ozone gas of standard concentration into the cavity of the high-precision cavity module; the high-precision cavity measurement module acquires the absorption signal when ozone of standard concentration is absorbed; the signal processing module obtains the harmonic signal amplitude V when ozone of standard concentration is absorbed based on the absorption signal when ozone of standard concentration is absorbed. S23, the signal processing module calculates the effective optical path L by fitting the ring-down time when measuring the background. eff Calculation of L: eff =cτ0; The signal processing module also utilizes standard concentrations of ozone gas to measure the effective optical path L. eff Calibration is performed by first obtaining the ozone gas absorption coefficient α based on the ozone concentration; then, using the formula for calculating the ozone gas absorption coefficient α, the standard effective optical path L is derived. eff ';The calculated effective optical path L eff Compared with standard effective optical path L eff 'Compare the results; if the error exceeds the set value, then use the standard effective optical path L.' eff 'The calculated effective optical path L eff Perform calibration.

8. A computer program product, characterized in that, It includes a computer program / instruction that, when executed by a processor, implements the effective optical path self-calibration ozone high-frequency measurement method as described in any one of claims 6-7.

9. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the ozone high-frequency measurement method with effective optical path self-calibration as described in any one of claims 6-7.

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