A miniaturized multi-optical path cell sherrington flask leak detection device and method

Abstract

The application discloses a kind of miniaturized multi-optical path cell's vial leak detection device and method in the technical field of nondestructive vial leak detection, laser drive circuit and modulation and demodulation circuit are embedded and installed in the inner chamber of box shell, the laser detection assembly includes arc equipment positioning plate, positioning plate fixing frame, multi-optical path cell, detector, laser and collimator, using tunable semiconductor laser spectroscopy technology, by the miniaturized multi-optical path cell of good design, the gas in vial is detected, realize high-precision, fast, on-line detection and other advantages based on the method of tunable semiconductor laser spectroscopy, solve the problems that traditional vial detection technology destroys sample, cannot be quantitatively measured, cannot be measured on-line etc.;Based on the method of vector calculation, suitable miniaturized multi-optical path cell can be customized according to the size information of vial, solve the problem that laser single-pass detection optical path is too short and sensitivity is low.

Description

Technical Field

[0001] This invention relates to the field of non-destructive vial leakage detection technology, and in particular to a miniaturized multi-path cell vial leakage detection device and method. Background Technology

[0002] A vial is a small glass vial sealed with a rubber stopper, commonly used for packaging vaccines, powder injections, biological agents, lyophilized drugs, and other pharmaceuticals. Because contact between the medication inside and external oxygen can cause the medication to deteriorate or even become contaminated with bacteria, this can pose a risk to the user.

[0003] Currently, the main methods used for leak detection of vials include electrochemical methods, chemical colorimetry, gas chromatography, microbial intrusion methods, and high-voltage spark discharge methods. Most of these are invasive detection methods, which have problems such as damaging the medicine, low measurement accuracy, and inability to achieve rapid online detection.

[0004] In view of the above-mentioned related technologies, the present invention provides a miniaturized multi-path cell vial leakage detection device and method. Summary of the Invention

[0005] This invention provides a miniaturized multi-path cell vial leakage detection device and method, which solves the problems of sample damage, inability to quantitatively measure, and inability to detect online in existing traditional vial detection technologies, as well as the problem of low detection sensitivity in non-destructive testing technologies.

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0007] In view of the above and / or existing problems in vial detection, the present invention is proposed.

[0008] Therefore, the problem to be solved by the present invention is how to provide a miniaturized multi-path cell vial leakage detection device.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a vial detection device based on a miniaturized multi-path cell, comprising: a vial detection mechanism, which includes a housing shell, a main control panel, a power supply, a flip-top door, a maintenance door, a vial transmission assembly, and a laser detection assembly. The main control panel is installed at the front end of the housing shell, the maintenance door is installed below the main control panel, and the flip-top door is located on the side of the housing shell. An operating handle is provided on the surface of the flip-top door, and the inlet and outlet ends of the vial transmission assembly pass through the housing shell and are placed in the inner cavity.

[0010] The inner cavity of the housing contains a laser drive circuit and a modulation and demodulation circuit. The laser detection assembly includes an arc-shaped equipment positioning plate, a positioning plate fixing frame, a multi-path cell, a detector, a laser, and a collimator. The multi-path cell is mounted on the arc-shaped equipment positioning plate and fixed to the sample tray to be tested by the positioning plate fixing frame.

[0011] Based on the above technical features: when testing vials, the device first places the vial sample to be tested into the sample tray, and then the transmission gears send each vial into the laser detection component for spectral detection. After the detection is completed, the transmission gears sort the vials, transferring qualified products to the qualified product tray and unqualified products to the unqualified product tray. Compared with general detection devices, it does not damage the sample to be tested, saves detection costs, and uses laser absorption spectroscopy to achieve rapid real-time online detection. It can not only perform quantitative detection, but also uses a miniaturized multi-path cell, which greatly improves the detection sensitivity.

[0012] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, the device is equipped with two sets of laser detection components, which can detect two vials at the same time, and the detection signal is received by a photodetector connected to the rear cavity cover.

[0013] Based on the above technical features: during detection, the vial is transported to the optical path cell by a transmission gear. The laser beam passes through a collimator and enters the miniaturized multi-optical path cell. After multiple reflections, the signal is received by the detector. After data processing, the detection result of the gas in the vial is reflected on the numerical display screen of the main control panel.

[0014] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, the arc-shaped positioning plate has multiple interfaces reserved, and laser detection components can be added according to the detection speed requirements to improve detection efficiency.

[0015] Based on the above technical features: the arc-shaped positioning plate is connected to the positioning plate bracket, and the positioning plate bracket has a height adjustment function. According to the size information of different vials, the positioning plate bracket can be adjusted to a suitable height to meet the headspace detection of the vials.

[0016] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, the multi-path cell uses two dielectric film reflectors, which have the characteristic of high reflectivity in the infrared band, which can reduce light intensity loss, effectively improve the absorption optical path, and increase detection sensitivity.

[0017] Based on the above technical features: by adjusting the collimator and the wire behind the front cavity cover, the incident angle is adjusted to change the number of reflections of the light beam in the multi-path cell, so as to meet the detection requirements. The light spot distribution in the multi-path cell is a vertical straight line distribution, so as to completely pass through the center of the vial and avoid the geometric deflection interference of the vial wall on the light beam.

[0018] In a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, the upper end of the transmission gear is equipped with an adjustment handle, and its operation is driven by a motor inside the housing. Its rotation speed is determined by the detection speed and can be adjusted through the main control panel.

[0019] Based on the above technical features: when testing vials of different sizes, the gear can be removed and replaced using the adjusting handle on the transmission gear to improve testing efficiency.

[0020] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, wherein: the laser is a tunable semiconductor laser, and the inner wall of the housing is blackened.

[0021] Based on the above technical characteristics, the wavelength of the laser is determined by the gas to be measured inside the vial, such as oxygen, water vapor, and carbon dioxide.

[0022] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, the laser driving circuit includes a temperature control module and a current control module, wherein the temperature control module adopts a TEC temperature control chip and the current control module adopts a feedback amplification circuit, and the modulation and demodulation circuit includes a signal generation module, a detector receiving module and a demodulation module.

[0023] Based on the above technical features: the temperature control module uses a TEC temperature control chip, which has advantages such as miniaturization, high safety factor, accuracy, high switching frequency, low noise, and good stability; the current control module uses feedback amplification to adjust and amplify the current as needed, and adopts an internal reverse connection protection design to ensure laser safety. The MCU monitors the temperature and current in real time, issuing timely warnings if they exceed the safe range. The modulation and demodulation circuit includes a signal generation module, a detector receiving module, and a demodulation module. The signal generation module includes sine wave signal generation; the detector receiving module includes multi-stage signal amplification; and the demodulation module demodulates the input signal.

[0024] As a preferred embodiment of the miniaturized multi-path cell vial leakage detection device of the present invention, it further includes a method for using the miniaturized multi-path cell vial leakage detection device, specifically comprising the following steps:

[0025] Step S1: Turn on the power and place the vial containing standard gas into the multi-path cell through the vial transmission assembly;

[0026] Step S2: Use the touch screen to turn on the laser for calibration and standardization;

[0027] Step S3: Turn off the laser, remove the vial containing standard gas through the vial transmission assembly, and place the vial sample to be tested into the multi-path cell;

[0028] Step S4: Use the touch screen to turn on the laser and observe the gas concentration information in the vial to be tested through the touch screen.

[0029] Preferably, the specific process for collecting the gas concentration inside the vial is as follows: A tunable semiconductor laser is used as the light source, and the driving temperature and current are adjusted using a laser driving circuit to scan different spectral ranges. A modulation signal is generated by the modulation / demodulation circuit, which is superimposed with a sine wave signal to form a modulation signal, which is then provided to the laser driver. After the laser passes through a multi-path cell and the vial, it is received by a detector and transmitted to a lock-in amplifier modulation / demodulation circuit for demodulation. The demodulated 2f signal is used to obtain the gas concentration information inside the vial by relating it to the concentration, and this information is then transmitted to a touchscreen display.

[0030] Preferably, the specific steps of signal data processing are as follows:

[0031] Step 1: Averaging: After scanning and detecting the same vial multiple times, the average signal is used as the detection signal to avoid errors that may be caused by a single measurement.

[0032] Step 2: Background Removal: Measure the scanning signal inside the chamber under conditions without test vials, and subtract the background signal from the scanning signal obtained in Step 1 to eliminate the influence of the background;

[0033] Step 3: Kalman filtering: The 2f detection signal obtained in Step 2 is filtered using the Kalman filtering method. The purpose is to further improve the signal-to-noise ratio of the detection signal and increase the detection sensitivity.

[0034] Preferably, a vector calculation method for multi-path cells is designed based on vial size information:

[0035] Step 1: First, to ensure that the light beam is completely confined within the cavity and propagates stably, the stability conditions of the optical cavity must be met: ,

[0036] in

[0037] ,

[0038] In the formula, g1 and g2 are the geometric parameters of the coaxial spherical cavity; L is the distance between the two mirrors; R1 and R2 are the radii of curvature of the two mirrors. By default, two identical mirrors are used, and the radius of curvature is R.

[0039] Step 2: Since the bottle wall is cylindrical, lateral propagation will cause geometric deflection loss. Therefore, to make the light path distribution parallel to the longitudinal direction of the bottle, the incident angle α in the y-axis direction is set to 0 degrees.

[0040] Step 3: After the light beam undergoes n reflections, two adjacent points M n-1 (x) n-1 ,y n-1 ,z n-1 ) and M n (x n ,y n ,z n The one-way distance between them is d. n It can be expressed by the following formula: ,

[0041] in, , , Let be the direction vectors of the light beam on the x, y, and z axes respectively at the nth reflection;

[0042] Step 4: Based on the radius of curvature R of the mirror and the relative position r of the mirror and the axis of symmetry, the surface equation can be obtained:

[0043] ;

[0044] Step 5: By selecting one of the x, y, or z directions, and solving the equations of the line and the surface simultaneously, we can obtain its coordinate position on the axis. The following formula uses the y-axis as an example: ,

[0045] in

[0046] ;

[0047] Step 6: Because the beam is affected by the bottle wall thickness t when passing through the flask, the beam is refracted and deflected in the z-direction. Therefore, we introduce a correction factor g to describe the actual beam propagation. n The position is given by the following formula: ,

[0048] in

[0049] ,

[0050] ,

[0051] Among them, y n The value is obtained from the formula in step 5, where t is the wall thickness of the vial and n2 is the refractive index of the vial material;

[0052] Step 7: k 1n ,k 2n ,k 3n These are the components of the surface normal vector along the x, y, and z axes, respectively, and their values ​​are given by the following formula: ;

[0053] Step 8: Direction vector at the (n-1)th reflection , , and the surface in M n-1 normal vector k 1n k 2n k 3n The direction vector at the nth reflection can be obtained. ,

[0054] in ;

[0055] Step 9: x can be calculated using the formulas from Step 5 and Step 3. n The distribution location of is given by the following formula: ;

[0056] Step 10: Since the multi-path cell used in the vial detection system is an open optical path, multiple reflections will also increase the optical path length in the free space outside the vial. Therefore, the effective optical path length L inside the vial is used. y With total optical path length L s The ratio k is used as one of the measurement standards. When k > 50%, it is considered that the multi-path cell effectively increases the optical path length inside the bottle, as shown in the following formula: ,

[0057] in

[0058] ,

[0059] ,

[0060] Where d is the diameter of the vial body, the relationship between the vial body diameter d and r and R can be obtained by combining the formula in step 5 and the above formula;

[0061] Step 11: Using the vector calculation method described above, the position information of each light spot can be calculated based on the initial conditions. Based on the size information of the vial to be measured, the vial diameter d and the vial wall thickness t, the required multi-path cell can be flexibly constructed by simply adjusting the incident position.

[0062] In summary, the present invention has at least one of the following beneficial effects:

[0063] 1. When detecting gas inside vials, the detection device of the present invention first places the vial sample to be tested into the sample tray, and then the transmission gears send each vial into the laser detection component for spectral detection. After the detection is completed, the transmission gears sort the vials, transferring qualified products to the qualified product tray and unqualified products to the unqualified product tray. Compared with general detection devices, it does not damage the sample to be tested, saves detection costs, and uses laser absorption spectroscopy to achieve rapid real-time online detection. It can not only perform quantitative detection, but also uses a miniaturized multi-path cell, which greatly improves the detection sensitivity. According to the size characteristics of the vials, the model of the transmission gears is adjusted, and the multi-path is adjusted and fixed appropriately according to the required optical path. It can not only perform rapid detection efficiently, but also achieve high-precision quantitative measurement of gas inside vials.

[0064] 2. The detection method of this invention utilizes tunable semiconductor laser spectroscopy technology. Through a well-designed miniaturized multi-path cell, it detects the gas inside the vial, achieving advantages such as high precision, speed, and online detection. Based on tunable semiconductor laser spectroscopy technology, this method solves the problems of traditional vial detection techniques, such as sample destruction, inability to quantitatively measure, and inability to perform online measurements. Based on vector calculation, a suitable miniaturized multi-path cell can be customized according to the size information of the vial, solving the problems of short optical path and low sensitivity in single-pass laser detection. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is an overall structural diagram of the miniaturized multi-path cell vial leakage detection device of the present invention;

[0067] Figure 2 This is a front view of the miniaturized multi-path cell vial leakage detection device of the present invention;

[0068] Figure 3 This is a schematic diagram of the vial transmission assembly structure of the present invention;

[0069] Figure 4 This is a top view of the vial transmission assembly of the present invention;

[0070] Figure 5 This is a schematic diagram of the multi-path cell structure of the present invention;

[0071] Figure 6 This is a simulation diagram of the light spot distribution and irradiance of the miniaturized multi-path cell of the present invention;

[0072] Figure 7 This is a simulation diagram of the miniaturized multi-path cell optical path of the present invention;

[0073] Figure 8 This is a schematic diagram of the miniaturized multi-path cell vector calculation principle of the present invention;

[0074] Figure 9 This is a schematic diagram of the miniaturized multi-path cell vector calculation principle of the present invention, taking into account the size of the vial;

[0075] Figure 10 This is a graph showing the measurement results of oxygen at different concentrations using the device of the present invention;

[0076] Figure 11 This is a graph showing the calibration results of the device of the present invention for oxygen at different concentrations.

[0077] Explanation of reference numerals in the attached drawings: 1. Vial testing mechanism; 11. Housing shell; 111. Moving roller; 112. Laser drive circuit; 113. Modulation and demodulation circuit; 12. Main control panel; 13. Power supply; 14. Flip-top door; 15. Maintenance door; 16. Vial transmission assembly; 161. Sample tray to be tested; 162. Qualified product tray; 163. Unqualified product tray; 164. Transmission gear; 1641. Adjustment handle; 17. Laser detection assembly; 171. Arc-shaped equipment positioning plate; 172. Positioning plate fixing frame; 173. Multi-path cell; 1731. Front cavity cover; 1732. Rear cavity cover; 1733. Incident end reflector; 1734. Exit end reflector; 174. Detector; 175. Laser; 176. Collimator. Detailed Implementation

[0078] The following is in conjunction with the appendix Figure 1-11 The present invention will be described in further detail below.

[0079] Example 1: Refer to Figure 1This invention discloses a miniaturized multi-path cell vial leakage detection device, comprising: a vial detection mechanism 1, which includes a housing 11, a main control panel 12, a power supply 13, a flip-top door 14, a maintenance door 15, a vial transmission assembly 16, and a laser detection assembly 17. The main control panel 12 is mounted on the front end of the housing 11, and the maintenance door 15 is mounted below the main control panel 12. The flip-top door 14 is located on the side of the housing 11, and an operating handle 141 is provided on the surface of the flip-top door 14. The inlet and outlet ends of the vial transmission assembly 16 pass through the housing 11 and are placed in the inner cavity. The device is used to detect vial leakage. When testing vials, the vial sample to be tested can be placed in the sample tray 161, and then the transmission gear 164 will send each vial into the laser detection component 17 for spectral detection. After the detection is completed, the transmission gear 164 will sort the vials, sending qualified products to the qualified product tray 162 and unqualified products to the unqualified product tray 163. Compared with general detection devices, it will not damage the sample to be tested, saving detection costs. The laser absorption spectroscopy method can achieve rapid real-time online detection, which can not only achieve quantitative detection, but also uses a miniaturized multi-path cell, which greatly improves the detection sensitivity.

[0080] Reference Figure 2 The bottom of the housing 11 is equipped with casters 111 for easy movement of the entire device. A laser drive circuit 112 and a modulation / demodulation circuit 113 are embedded in the inner cavity of the housing 11. The laser drive circuit 112 includes a temperature control module and a current control module. The temperature control module uses a TEC temperature control chip, which has advantages such as miniaturization, high safety factor, precision, high switching frequency, low noise, and good stability. The current control module uses feedback amplification to adjust and amplify the current as needed, and adopts an internal reverse connection protection design to ensure laser safety. An MCU monitors the temperature and current in real time, issuing warnings promptly if they exceed safe ranges. The modulation / demodulation circuit 113 includes a signal generation module, a detector receiving module, and a demodulation module. The signal generation module generates a sinusoidal modulation signal; the detector receiving module amplifies the signal through multiple stages; and the demodulation module demodulates the input signal.

[0081] Reference Figures 3-5The vial transmission assembly 16 includes a sample tray 161 for holding vials to be tested, a qualified product tray 162 for receiving vials that have passed sorting, and a non-qualified product tray 163 for receiving vials that have failed sorting. A transmission gear 164 feeds the vials located on the sample tray 161 into the laser detection assembly 17 for spectral detection. An adjustment handle 1641 is used to manually adjust the transmission gear. The laser detection assembly 17 includes an arc-shaped equipment positioning plate 171, a positioning plate fixing frame 172, a multi-path cell 173, a detector 174, a laser 175, and a collimator 176. The multi-path cell 173 is mounted on the arc-shaped equipment positioning plate 171 and fixed to the sample tray 161 by the positioning plate fixing frame 172. The multi-path cell 173 includes a front cover 1731, a rear cover 1732, an incident reflector 1733, and an exit reflector 1734. The incident and exit reflectors 1733 and 1734 have countersunk entrance / exit holes at different positions on their surfaces to achieve larger entrance and exit angles. The rear end of the front cover 1731 has screws and guide screws for angle adjustment. A collimator 176 is connected to the front cover 1731, and its rear end also has screws and guide screws for angle adjustment.

[0082] The laser driving circuit 112 includes a temperature control module and a current control module. The temperature control module uses a TEC temperature control chip, and the current control module uses a feedback amplifier circuit. The modulation and demodulation circuit 113 includes a signal generation module, a detector receiving module, and a demodulation module. The signal generation module includes sinusoidal signal generation; the detector receiving module includes multi-stage signal amplification; and the demodulation module demodulates the input signal.

[0083] Example 2: This example further illustrates Example 1. The laser 175 is a tunable semiconductor laser, and the inner wall of the housing 11 is blackened. The wavelength of the laser 175 is determined by the gas to be measured in the vial, such as oxygen, water vapor, and carbon dioxide.

[0084] Example 3: A miniaturized multi-path cell vial leakage detection device and method, the specific steps of which are as follows:

[0085] Step S1: Turn on the power supply 13 and place the vial containing standard gas into the multi-path cell 173 through the vial transmission assembly 16;

[0086] Step S2: Use the touch display 12 to turn on the laser 175 for calibration and standardization;

[0087] Step S3: Turn off the laser 175, take out the vial containing standard gas through the vial transmission assembly 16 and put the vial sample to be tested into the multi-path cell 173;

[0088] Step S4: Use the touch screen 12 to turn on the laser 175 and observe the gas concentration information in the vial to be tested through the touch screen 12.

[0089] In this embodiment, taking the measurement of oxygen in a vial as an example, the standard gas used is a mixture of oxygen and nitrogen, and the measurement results for different concentrations are as follows: Figure 10 As shown, the calibration results are as follows: Figure 11 As shown.

[0090] Example 4: This example further illustrates Example 3. Please refer to [link / reference]. Figures 6-9 As shown, the specific process for collecting the gas concentration inside the vial is as follows: A tunable semiconductor laser is used as the light source, and the driving temperature and current are adjusted by the laser driving circuit to scan different spectral ranges. The modulation and demodulation circuit generates a triangular wave signal, which is superimposed with a sine wave signal to form a modulation signal, which is provided to the laser driver. After the laser passes through the multi-path cell and the vial, it is received by the detector and transmitted to the lock-in amplifier modulation and demodulation circuit for demodulation. The demodulated 2f signal is used to obtain the gas concentration information inside the vial by relating it to the concentration, and then transmitted to the touch screen display.

[0091] The specific steps of signal data processing are as follows:

[0092] Step 1: Averaging: After scanning and detecting the same vial multiple times, the average signal is used as the detection signal to avoid errors that may be caused by a single measurement.

[0093] Step 2: Background Removal: Measure the scanning signal inside the chamber under conditions without test vials, and subtract the background signal from the scanning signal obtained in Step 1 to eliminate the influence of the background;

[0094] Step 3: Kalman filtering: The 2f detection signal obtained in Step 2 is filtered using the Kalman filtering method. The purpose is to further improve the signal-to-noise ratio of the detection signal and increase the detection sensitivity.

[0095] A vector calculation method for multi-path cells is designed based on the bottle size information:

[0096] Step 1: First, to ensure that the light beam is completely confined within the cavity and propagates stably, the stability conditions of the optical cavity must be met: ,

[0097] in

[0098] ,

[0099] In the formula, g1 and g2 are the geometric parameters of the coaxial spherical cavity; L is the distance between the two mirrors; R1 and R2 are the radii of curvature of the two mirrors. By default, two identical mirrors are used, and the radius of curvature is R.

[0100] Step 2: Since the bottle wall is cylindrical, lateral propagation will cause geometric deflection loss. Therefore, to make the light path distribution parallel to the longitudinal direction of the bottle, the incident angle α in the y-axis direction is set to 0 degrees.

[0101] Step 3: After the light beam undergoes n reflections, two adjacent points M n-1 (x) n-1 ,y n-1 ,z n-1 ) and M n (x n ,y n ,z n The one-way distance between them is d. n It can be expressed by the following formula: ,

[0102] in, , , Let be the direction vectors of the light beam on the x, y, and z axes respectively at the nth reflection;

[0103] Step 4: Based on the radius of curvature R of the mirror and the relative position r of the mirror and the axis of symmetry, the surface equation can be obtained: ;

[0104] Step 5: By selecting one of the x, y, or z directions, and solving the equations of the line and the surface simultaneously, we can obtain its coordinate position on the axis. The following formula uses the y-axis as an example: ,

[0105] in ;

[0106] Step 6: Because the beam is affected by the bottle wall thickness t when passing through the flask, the beam is refracted and deflected in the z-direction. Therefore, we introduce a correction factor g to describe the actual beam propagation. n The position is given by the following formula: ,

[0107] in ,

[0108] ,

[0109] Among them, y n The value is obtained from the formula in step 5, where t is the wall thickness of the vial and n2 is the refractive index of the vial material;

[0110] Step 7: k 1n ,k 2n ,k 3nThese are the components of the surface normal vector along the x, y, and z axes, respectively, and their values ​​are given by the following formula: ;

[0111] Step 8: Direction vector at the (n-1)th reflection , , and the surface in M n-1 normal vector k 1n k 2n k 3n The direction vector at the nth reflection can be obtained. ,

[0112] in ;

[0113] Step 9: x can be calculated using the formulas from Step 5 and Step 3. n The distribution location of is given by the following formula: ;

[0114] Step 10: Since the multi-path cell used in the vial detection system is an open optical path, multiple reflections will also increase the optical path length in the free space outside the vial. Therefore, the effective optical path length L inside the vial is used. y With total optical path length L s The ratio k is used as one of the measurement standards. When k > 50%, it is considered that the multi-path cell effectively increases the optical path length inside the bottle, as shown in the following formula: ,

[0115] in ,

[0116] ,

[0117] Where d is the diameter of the vial body, the relationship between the vial body diameter d and r and R can be obtained by combining the formula in step 5 and the above formula;

[0118] Step 11: Using the vector calculation method described above, the position information of each light spot can be calculated based on the initial conditions. Based on the size information of the vial to be measured, the vial diameter d and the vial wall thickness t, the required multi-path cell can be flexibly constructed by simply adjusting the incident position.

[0119] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A miniaturized multi-optical-path cell's vial leak detection device, characterized by: include, The vial testing mechanism includes a housing, a main control panel, a power supply, a tilting door, a maintenance door, a vial transmission assembly, and a laser detection assembly. The main control panel is mounted on the front of the housing, and the maintenance door is located below the main control panel. A tilting door is located on the side of the housing, and an operating handle is provided on the surface of the tilting door. The inlet and outlet ends of the vial transmission assembly pass through the housing and are placed within the inner cavity. The inner cavity of the housing is embedded with a laser driving circuit and a modulation and demodulation circuit. The laser detection component includes an arc-shaped equipment positioning plate, a positioning plate fixing frame, a multi-path cell, a detector, a laser, and a collimator. The multi-path cell is mounted on the arc-shaped equipment positioning plate and fixed to the sample tray to be tested by the positioning plate fixing frame. The multi-path cell includes a front cavity cover, a rear cavity cover, an incident end reflector, and an exit end reflector. The incident end reflector and the exit end reflector have incident / exit holes at different positions on their mirror surfaces, and these holes are countersunk. The rear end of the front cavity cover has screws and mating threads for adjusting the angle. The bottom of the housing is equipped with movable rollers, the collimator is connected to the front cover, and the rear end of the collimator is equipped with screws and threaded rods for adjusting the angle. The laser is a tunable semiconductor laser, and the inner wall of the housing is blackened. The laser driving circuit includes a temperature control module and a current control module. The temperature control module uses a TEC temperature control chip, and the current control module uses a feedback amplifier circuit. The modulation and demodulation circuit includes a signal generation module, a detector receiving module, and a demodulation module. The signal generation module generates a sine wave; the detector receiving module amplifies the signal through multiple stages; and the demodulation module demodulates the input signal.

2. A miniaturized multi-optical-path cell's vial leak detection device according to claim 1, characterized in that: The vial transmission assembly includes a sample tray, a qualified product tray, a non-qualified product tray, and a transmission gear, which has an adjustable handle.

3. A method for detecting the leakage of a miniaturized multi-optical path cell's vial, comprising the miniaturized multi-optical path cell's vial leakage detection device of any one of claims 1-2, characterized in that: Specifically, the following steps are included: Step S1: Turn on the power and place the vial containing standard gas into the multi-path cell through the vial transmission assembly; Step S2: Use the touch screen to turn on the laser for calibration and standardization; Step S3: Turn off the laser, remove the vial containing standard gas through the vial transmission assembly, and place the vial sample to be tested into the multi-path cell; Step S4: Use the touch screen to turn on the laser and observe the gas concentration information in the vial to be tested through the touch screen.

4. The method of claim 3, wherein the method is used for detecting the leakage of a miniaturized multi-optical-path cell. In step S4, the specific process of obtaining the gas concentration information in the vial to be tested observed on the touch screen is as follows: A tunable semiconductor laser is used as the light source. The driving temperature and current are adjusted by the laser driving circuit to scan different spectral ranges. The modulation and demodulation circuit generates a triangular wave signal superimposed with a sine wave signal to form a modulation signal, which is provided to the laser driver. After the laser passes through the multi-path cell and the vial, it is received by the detector and transmitted to the lock-in amplifier modulation and demodulation circuit for demodulation. The demodulated 2f signal obtains the gas concentration information in the vial to be tested through the relationship with the concentration and is transmitted to the touch screen.

5. The method of claim 3, wherein the method is used for detecting the leakage of a miniaturized multi-optical-path cell. Before step S1, there is also step S0, which involves constructing the required multi-path cell based on the vial size information. The vector calculation steps for the required multi-path cell are as follows: Step 1: First, to make the light beam in the multi-path cell completely confined in the cavity and stably propagate, the stable condition of the optical cavity needs to be met: wherein ; In the formula, g1 and g2 are the geometric parameters of the coaxial spherical cavity; L is the distance between the two mirrors; R1 and R2 are the radii of curvature of the two mirrors. By default, two identical mirrors are used, and the radius of curvature is R. Step 2: Since the bottle wall is cylindrical, lateral propagation will cause geometric deflection loss. Therefore, to make the light path distribution parallel to the longitudinal direction of the bottle, the incident angle α in the y-axis direction is set to 0 degrees. Step 3: The one-way distance between two adjacent points M n-1 (x n-1 ,y n-1 ,z n-1 ) and M n (x n ,y n ,z n ) after n reflections of the light beam is d n , which can be expressed as follows: ; wherein , , are the direction vectors of the light beam in the x, y, z axes at the n-th reflection; Step 4: The curved surface equation can be obtained according to the curvature radius R of the mirror and the relative position r of the mirror and the symmetry axis: ; Step 5: By selecting one of the x, y, z directions, the straight line equation and the curved surface equation are solved to obtain the coordinate position on the axis, the following formula takes the y-axis direction as an example: , wherein ; Step 6: Since the light beam is affected by the thickness of the bottle wall t when it passes through the bottle, the light beam is refracted and will produce a shift in the z direction, so we introduce a correction factor g to describe the actual light beam propagation, z n The position of the light beam is given by: , wherein , ， where y n The value of t is obtained from the formula of step 5, t is the wall thickness of the vial, n2 is the refractive index of the vial material. Step 7: k 1n ,k 2n ,k 3n are the components of the surface normal vector in the x, y, z axis directions, given by: ; Step 8: Direction vector at the n-th reflection by using the direction vector at the (n-1)-th reflection , , and the normal vector k n-1 of the surface at M 1n , k 2n , k 3n The direction vector at the n-th reflection is available, ， in ; Step 9: x can be calculated using the formulas from Step 5 and Step 3. n The distribution location of is given by the following formula: ; Step 10: Since the multi-path cell used in the vial detection system is an open optical path, multiple reflections will also increase the optical path length in the free space outside the vial. Therefore, the effective optical path length L inside the vial is used. y With total optical path length L s The ratio k is used as one of the measurement standards. When k > 50%, it is considered that the multi-path cell effectively increases the optical path length inside the bottle, as shown in the following formula: , in ， ， Where d is the diameter of the vial body, the relationship between the vial body diameter d and r and R can be obtained by combining the formula in step 5 and the above formula; Step 11: Using the vector calculation method described above, the position information of each light spot can be calculated based on the initial conditions. Based on the size information of the vial to be measured, the vial diameter d and the vial wall thickness t, the required multi-path cell can be flexibly constructed by simply adjusting the incident position.

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