An explosion-proof full-state optical principle oxygen concentration measurement device and method

Abstract

The present invention discloses an explosion-proof full-state optical principle oxygen concentration measuring device, and also discloses a measuring method for the explosion-proof full-state optical principle oxygen concentration measuring device. First, the explosion-proof optical oil level detector is installed and fixed in direct contact with the dangerous explosion-proof space area inside the oil tank through a KF40 vacuum sealing joint to detect the change of kerosene level; the pure gas filtered by the precision gas filter isolator is measured by the optical intensity attenuation of the laser light emitting LD device and the photoelectric detection diode, and finally the electronic signal processing module outputs the converted gas concentration data through the signal electrical connector; and then the original measured gas is returned to the aircraft tank through the return tank gas connector. The present invention solves the problems existing in the prior art of directly measuring the oxygen concentration value of the gas in a complex environment and the problems of inaccurate or damaged measuring devices caused by explosion-proof and various angles of light, pressure, and temperature.

Description

Technical Field

[0001] The present invention belongs to the technical field of measurement with explosion-proof grade requirements, and specifically relates to an explosion-proof grade full-state optical principle oxygen concentration measurement device. The present invention also relates to an explosion-proof grade full-state optical principle oxygen concentration measurement method. Background Art

[0002] The kerosene liquid surface inside the aircraft fuel tank and the space above the tank are the dangerous areas where kerosene vapor mixes. To ensure the safety of the kerosene vapor area, it is necessary to monitor the oxygen concentration in the kerosene vapor space after nitrogen inerting in real time to ensure that the oxygen concentration in the kerosene vapor space is not higher than the safe concentration value (9% or below 12%) to ensure the safety of the aircraft fuel tank and flight.

[0003] Since the kerosene vapor mixing space in the upper part of the aircraft fuel tank is itself a dangerous explosion-proof area, in order to safely measure the oxygen content in this space, the measurement method and the device itself need to have an explosion-proof grade.

[0004] Due to the carrier characteristics of the aircraft fuel tank, the measurement state of the fuel tank is always in complex motion changes, including the pitch, roll (inverted flight), yaw and other attitudes of the fuel tank, as well as the complex changes of the total pressure, temperature and kerosene level of the internal environment of the fuel tank.

[0005] In summary, the measuring device needs to be installed inside the aircraft fuel tank, have an explosion-proof grade, and meet the full-state measurement of the tank's pitch, roll (inverted flight), yaw and other postures, and adapt to changes in the internal environmental parameters of the tank. Summary of the invention

[0006] The purpose of the present invention is to provide an explosion-proof grade full-state optical principle oxygen concentration measuring device, which solves the problem in the prior art of directly measuring the oxygen concentration of gas in a complex environment and the problem of inaccurate or damaged measuring devices due to explosion-proof and various angles of light, pressure and temperature.

[0007] Another object of the present invention is to provide a measurement method of an explosion-proof grade full-state optical principle oxygen concentration measurement device.

[0008] The first technical solution adopted by the present invention is an explosion-proof grade full-state optical principle oxygen concentration measuring device, including an explosion-proof optical oil level detector extending into the interior of the aircraft fuel tank, the air inlet of the explosion-proof optical oil level detector is located above the kerosene liquid level inside the aircraft fuel tank, the air outlet of the explosion-proof optical oil level detector is located in the kerosene inside the aircraft fuel tank, and an explosion-proof micro solenoid valve is also arranged inside the explosion-proof optical oil level detector, the explosion-proof micro solenoid valve is also connected to the 3D printed kerosene particle filter cavity, the top of the 3D printed kerosene particle filter cavity is connected to the precision gas filter isolator, and the explosion-proof micro solenoid valve is connected to the electronic The signal processing module is connected to the power supply and signal output module, which is in turn connected to the signal electrical connector. The signal electrical connector is sealed and connected through the device housing, so that the device as a whole is connected to the external power signal output. The electronic signal processing module is sequentially connected to the photoelectric signal conversion module, the laser light-emitting LD device, and the photoelectric detection diode. The photoelectric signal conversion module is also connected to the A / D conversion module. The electronic signal processing module is also connected to the explosion-proof optical oil level detector and the diaphragm gas driver. The lower part of the structural housing is connected to the inside of the aircraft fuel tank through a KF40 vacuum sealing joint.

[0009] The first technical solution of the present invention is also characterized in that:

[0010] The explosion-proof micro solenoid valve is provided with an explosion-proof micro solenoid valve inlet and an explosion-proof micro solenoid valve outlet. The explosion-proof micro solenoid valve inlet is connected to the air inlet of the explosion-proof optical oil level detector through an inlet joint, and the explosion-proof micro solenoid valve outlet is connected to the 3D printed kerosene particle filter cavity through the 3D printed filter cavity inlet. The top of the 3D printed kerosene particle filter cavity is connected to the sealed isolation optical measurement cavity inlet of the sealed isolation optical measurement cavity through the 3D printed filter cavity outlet. The sealed isolation optical measurement cavity is also provided with a sealed isolation optical measurement cavity outlet; the optical measurement cavity is also connected to the diaphragm gas driver outlet opened on the diaphragm gas driver, and the diaphragm gas driver is placed on the diaphragm gas driver base. The hose passes through the diaphragm gas driver outlet, the sealed isolation optical measurement cavity outlet, and the return oil tank gas connector in sequence and is connected to the air outlet of the explosion-proof optical oil level detector. A one-way check valve is also provided on the hose between the sealed isolation optical measurement cavity outlet and the return oil tank gas connector for sealing isolation. A sealing ring is also provided between the above components for sealing.

[0011] The second technical solution adopted by the present invention is a measurement method of an explosion-proof full-state optical principle oxygen concentration measuring device, which is based on the explosion-proof full-state optical principle oxygen concentration measuring device and is specifically implemented according to the following steps:

[0012] Step 1: First, install and fix the explosion-proof optical oil level detector inside the oil tank through the KF40 vacuum sealing joint to directly contact the dangerous explosion-proof space area to detect the change of kerosene level;

[0013] Step 2, when the explosion-proof optical oil level detector installed inside the oil tank is not submerged by the kerosene level, the electronic signal processing module controls the explosion-proof micro solenoid valve and the diaphragm gas driver to be in an open state;

[0014] Step 3: The gas to be measured located in the dangerous area inside the oil tank is driven by the diaphragm gas driver and passes through the gas inlet connector, the explosion-proof micro solenoid valve, the 3D printed filter chamber inlet, the 3D printed filter chamber outlet, and then passes through the sealed isolation optical measurement chamber inlet to enter the sealed isolation optical measurement chamber;

[0015] Step 4: Inside the sealed isolated optical measurement cavity, the pure gas filtered by the precision gas filter isolator is measured for optical intensity attenuation through the laser light emitting LD device and the photoelectric detection diode, and the photoelectric signal conversion module transmits the measured original optical intensity signal to the electronic signal processing module, and finally the electronic signal processing module outputs the converted gas concentration data through the signal electrical connector;

[0016] Step 5: The filtered and measured gas passes through the outlet of the sealed and isolated optical measurement cavity, the outlet of the diaphragm gas driver, and finally through the return tank gas connector to return the original measured gas to the aircraft tank. At this point, the oxygen concentration content of the atmosphere inside the tank in a dangerous environment is measured.

[0017] The second technical solution of the present invention is also characterized in that:

[0018] The signal electrical connector in the power supply and signal output module, i.e., the aviation plug, provides an external DC28V power supply which is converted into DC5V and DC3.3V by a DC / DC power converter and fed to the electronic signal processing module and the photoelectric signal conversion module at the same time, thus realizing power supply and signal transmission of the entire device.

[0019] The photoelectric signal conversion module includes a laser light-emitting LD device. Under the control of the photoelectric A / D microcontroller, the laser light-emitting LD device emits pulse light beams of the same wavelength and light intensity at intervals. After passing through sealed gas chambers of different concentrations, light pulses with different light intensity attenuation are generated. After being received by a photoelectric detection diode, the light pulses of different light intensities are converted into electrical pulses of different voltages. After the photoelectric A / D microcontroller measures and digitizes the electrical pulses of different voltages, the original measurement data is output to the electronic signal processing module via a TTL level UART interface.

[0020] The functions of the electronic signal processing module include data level conversion and I / O port control.

[0021] The data level conversion is specifically as follows: the electronic signal processing module converts the TTL level UART interface signal from the photoelectric signal conversion module into an RS485 level signal, and transmits it to the remote customer data receiver through the signal electrical connector.

[0022] The I / O port control is specifically as follows: the electronic signal processor determines the kerosene level signal of the explosion-proof optical oil level detector through the high and low level changes of the I / O pin. If the explosion-proof optical oil level detector is submerged in kerosene in the fuel tank, the high and low levels of the input I / O pin of the electronic signal processor are reversed, and the output I / O pin of the electronic signal processor outputs high and low levels to control the explosion-proof micro solenoid valve and diaphragm gas driver to open or close.

[0023] The beneficial effect of the present invention is that an explosion-proof grade full-state optical principle oxygen concentration measurement device can be used in dangerous measurement environments such as mixed oil and gas with various requirements. The method and device will not produce electron energy accumulation to cause explosion hazards, and meet the complex measurement requirements under full-state measurement conditions of oil and gas mixtures.

[0024] The device can realize continuous measurement without being affected when the oil tank is in various motion states, including when the oil tank is inverted and the internal kerosene floods the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the measuring device components for this application;

[0026] Figure 2 This is a schematic diagram of the circuit framework of the power supply and signal output module of this application;

[0027] Figure 3 This is a schematic diagram of the circuit framework of the photoelectric signal conversion module of this application;

[0028] Figure 4 This is a schematic diagram of the circuit framework of the electronic signal processing module of this application;

[0029] Figure 5 Schematic diagram of the overall action logic of this application;

[0030] Figure 6 A schematic diagram of the internal airflow of the measurement device for this application;

[0031] Figure 7 It is the device IO action control logic diagram in the present invention;

[0032] Figure 8 This is a schematic diagram of different measurement states of the measurement device of this application;

[0033] Fig. 9 This is a schematic diagram of the experimental operation logic of the measurement device for this application;

[0034] Fig.10This is a structural diagram of the optical path oil and gas filter component of the measurement device for this application.

[0035] In the figure, 1. explosion-proof optical oil level detector, 2. KF40 vacuum sealing joint, 3. explosion-proof micro solenoid valve, 4. hose, 5. 3D printed kerosene particle filter cavity, 6. one-way check valve, 7. precision gas filter isolator, 8. photoelectric detection diode, 9. photoelectric signal conversion module, 10. laser light emitting LD device, 11. electronic signal processing module, 12. sealed isolation optical measurement cavity, 13. diaphragm gas driver base, 14. diaphragm gas driver, 15. sealing ring, 16. power supply and signal output module, 17. signal electrical connector, 18. inlet joint, 19. explosion-proof micro solenoid valve inlet, 20. explosion-proof micro solenoid valve outlet, 21. 3D printed filter cavity inlet, 22. 3D printed filter cavity outlet, 23. sealed isolation optical measurement cavity inlet, 24. sealed isolation optical measurement cavity outlet, 25. diaphragm gas driver outlet, 26. fuel tank return gas joint, 27. aircraft fuel tank. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] This device meets the explosion-proof grade requirements. All devices that are in direct contact with the dangerous environment of oil and gas mixture inside the oil tank are optical devices for pure light intensity and spectrum measurement, such as Figure 1 As shown, it mainly includes an explosion-proof optical oil level detector 1, a photoelectric detection diode 8, etc. The voltage and current peak values ​​are far below the certified values, there is no dangerous electronic energy, and it meets the explosion-proof standards. This method and device have obtained the national explosion-proof grade: ExiaⅡCT4 Ga certification.

[0038] In order to meet the explosion-proof grade requirements, a 3D printed kerosene particle filter cavity 5 is designed, so that the oil and gas particles entering the cavity are gravity-precipitated in the cavity and the filter screen is used to block and remove oil, ensuring that the gas entering other parts of the device after passing through the filter cavity is clean and oil-free, dry and safe, and completely isolates the dangerous area that needs to be measured by this method.

[0039] The present invention provides an explosion-proof full-state optical principle oxygen concentration measuring device, such as Figure 1 As shown, it includes an explosion-proof optical oil level detector 1 extending into the aircraft fuel tank 27, the model is LLC510D3, the air inlet of the explosion-proof optical oil level detector 1 is located above the kerosene liquid level inside the aircraft fuel tank, and the air outlet of the explosion-proof optical oil level detector 1 is located in the kerosene inside the aircraft fuel tank. An explosion-proof micro solenoid valve 3 is also arranged inside the explosion-proof optical oil level detector 1, and the explosion-proof micro solenoid valve 3 is MB205. The explosion-proof micro solenoid valve 3 is also connected to the 3D printed kerosene particle filter cavity 5. The structure of the 3D printed kerosene particle filter cavity 5 is as shown in FIG. Fig.10As shown, the top of the 3D printed kerosene particle filter cavity 5 is connected to the precision gas filter isolator 7, the explosion-proof micro solenoid valve 3 is connected to the electronic signal processing module 11 and the power supply and signal output module 16 in sequence, the power supply and signal output module 16 is connected to the signal electrical connector 17, the signal electrical connector 17 is sealed through the device housing, so that the device as a whole is connected to the external power signal output, the electronic signal processing module 11 is connected to the photoelectric signal conversion module 9, the laser light emitting LD device 10, and the photoelectric detection diode 8 in sequence, the photoelectric signal conversion module 9 is also connected to the A / D conversion module, the electronic signal processing module 11 is also connected to the explosion-proof optical oil level detector 1 and the diaphragm gas driver 14, and the lower part of the structural shell is connected to the inside of the aircraft fuel tank through the KF40 vacuum sealing joint 2.

[0040] The explosion-proof micro solenoid valve 3 is provided with an explosion-proof micro solenoid valve inlet 19 and an explosion-proof micro solenoid valve outlet 20. The explosion-proof micro solenoid valve inlet 19 is connected to the air inlet of the explosion-proof optical oil level detector 1 through an inlet joint 18. The explosion-proof micro solenoid valve outlet 20 is connected to the 3D printed kerosene particle filter cavity 5 through a 3D printed filter cavity inlet 21. The top of the 3D printed kerosene particle filter cavity 5 is connected to the sealed isolated optical measurement cavity inlet 23 of the sealed isolated optical measurement cavity 12 through a 3D printed filter cavity outlet 22. The sealed isolated optical measurement cavity 12 is also provided with a sealed isolated optical measurement cavity outlet 2 4; the sealed isolation optical measuring cavity 12 is also connected to the diaphragm gas driver outlet 25 opened on the diaphragm gas driver 14, the diaphragm gas driver 14 is placed on the diaphragm gas driver base 13, the hose 4 passes through the diaphragm gas driver outlet 25, the sealed isolation optical measuring cavity outlet 24, and the oil return tank gas connector 26 in sequence and is connected to the gas outlet of the explosion-proof optical oil level detector 1, and a one-way check valve 6 is also arranged on the hose 4 between the sealed isolation optical measuring cavity outlet 24 and the oil return tank gas connector 26 for sealing and isolation, and a sealing ring 15 is also arranged between the above-mentioned components for sealing.

[0041] A measurement method of an explosion-proof full-state optical principle oxygen concentration measuring device is based on the explosion-proof full-state optical principle oxygen concentration measuring device, and is specifically implemented according to the following steps:

[0042] Step 1: First, install and fix the explosion-proof optical oil level detector 1 in direct contact with the dangerous explosion-proof space area inside the oil tank through the KF40 vacuum sealing joint 2 to detect the change of kerosene level;

[0043] Step 2: When the explosion-proof optical oil level detector 1 installed inside the oil tank is not submerged by the kerosene level, the electronic signal processing module 11 controls the explosion-proof micro solenoid valve 3 and the diaphragm gas driver 14 to be in an open state;

[0044] Step 3: Figure 6As shown, the measured gas located in the dangerous area inside the oil tank is driven by the diaphragm gas driver 14 and passes through the gas inlet connector 18, the explosion-proof micro solenoid valve 3, the 3D printed filter chamber inlet 21, the 3D printed filter chamber outlet 22 in sequence, and then passes through the sealed isolation optical measurement chamber inlet 23 to enter the sealed isolation optical measurement chamber 12;

[0045] Step 4: Inside the sealed isolated optical measurement cavity 12, the pure gas filtered by the precision gas filter isolator 7 is measured for optical intensity attenuation through the laser light emitting LD device 10 and the photoelectric detection diode 8, and the photoelectric signal conversion module 9 transmits the measured original optical intensity signal to the electronic signal processing module 11, and finally the electronic signal processing module 11 outputs the converted gas concentration data through the signal electrical connector 17;

[0046] Step 5, the filtered and measured gas passes through the sealed and isolated optical measurement cavity outlet 24, the diaphragm gas driver outlet 25, and finally through the fuel tank return gas connector 26, and the original measured gas is pumped back into the aircraft fuel tank 27. At this point, the oxygen concentration content of the atmosphere inside the fuel tank in a dangerous environment is measured.

[0047] The present invention is isolated by the 3D printed kerosene particle filter cavity 5, and all devices with tiny electronic energy will not contact with the dangerous environment of oil and gas mixture, including the explosion-proof micro solenoid valve 3, the photoelectric signal conversion module 9, the electronic signal processing module 11, etc. Figure 1 shown.

[0048] The signal electrical connector 17 (aviation plug) is sealed and connected to the device housing, so that the entire device is connected to the external power supply and signal output.

[0049] Power supply and signal output module 16: In the hardware circuit of the power supply and signal output module 16, the signal electrical connector 17, i.e., the aviation plug, provides an external DC28V power supply which is converted into DC5V and DC3.3V by a DC / DC power converter and fed to the electronic signal processing module 11 and the photoelectric signal conversion module 9 at the same time, so as to realize the power supply and signal transmission of the whole device. Figure 2 shown.

[0050] The photoelectric signal conversion module 9 includes a laser light emitting LD device 10. The laser light emitting LD device 10 emits pulse light beams of the same wavelength and light intensity at intervals under the control of the photoelectric A / D microcontroller. After passing through sealed gas chambers with different concentrations, light pulses with different light intensity attenuation are generated. After being received by the photoelectric detection diode 8, the light pulses with different light intensities are converted into electrical pulses with different voltages. After the photoelectric A / D microcontroller measures and digitally processes the electrical pulses with different voltages, the original measurement data is output to the electronic signal processing module 11 via a TTL level UART interface. Figure 3shown.

[0051] The functions of the electronic signal processing module 11 include data level conversion and I / O port control, such as Figure 4 As shown, 1. Data level conversion: In the hardware circuit of the electronic signal processing module 11, the electronic signal processor converts the TTL level UART interface signal from the photoelectric signal conversion module 9 into an RS485 level signal, and transmits it to the remote customer data receiver through the signal electrical connector 17. 2. I / O port control: As shown Figure 7 As shown, the electronic signal processor determines the kerosene level signal of the explosion-proof optical oil level detector 1 by the high and low level changes of the I / O pin. If the explosion-proof optical oil level detector 1 is submerged by kerosene in the oil tank, the high and low levels of the input I / O pin of the electronic signal processor are reversed, and the output I / O pin of the electronic signal processor outputs high and low levels to control the explosion-proof micro solenoid valve 3 and the diaphragm gas driver 14 to open or close.

[0052] The overall action logic of the present invention is as follows Figure 5 The experimental operation logic diagram is shown in Fig. 9 As shown:

[0053] The present invention designs a 3D printed complex structure oil and gas filter cavity assembly to ensure that the aircraft fuel tank 27 carrier can reliably filter oil and gas when measured in any posture state, such as Fig.10 As shown, the component mainly includes a 3D printed kerosene particle filter cavity 5, a 3D printed filter cavity inlet 21, and a 3D printed filter cavity outlet 22. The innovation of the present invention is that the device must be directly installed in the oil-gas mixing dangerous area inside the fuel tank and directly powered for operation. 1. The device method itself needs to meet the requirements of explosion-proof standards and will not introduce additional dangerous points inside the fuel tank. 2. The device must be able to directly contact the kerosene inside the fuel tank, and automatically, safely and reliably make direct, rapid and reliable detection feedback on the changes in the kerosene liquid level in the moving state. The specific contents are as follows.

[0054] 1. The technical approach of the present invention to meet the requirements of explosion-proof standards includes the following:

[0055] 1.1, such as Figure 1 As shown, the entire device directly extends into the dangerous area inside the oil tank through the KF40 vacuum sealing joint 2. All devices that are in direct contact with the dangerous area must comply with explosion-proof standards, such as the explosion-proof optical oil level detector 1 and the explosion-proof micro solenoid valve 3.

[0056] 1.2. All devices and pipelines that are not in direct contact with the dangerous area inside the fuel tank are filtered and isolated by the 3D printed kerosene particle filter cavity 5 and the precision gas filter isolator 7 inside the method device, and are completely isolated from the dangerous area inside the fuel tank and only come into contact with pure, dry and oil-free air.

[0057] 1.3. The core measuring photoelectric conversion devices of the present invention, such as the laser light-emitting LD device 10, the photoelectric detection diode 8, the analog-to-digital A / D conversion module circuit, the photoelectric signal conversion module 9, the electronic signal processing module 11, the power supply and signal output module 16 circuit are all designed and tested according to the extremely low energy low voltage DC3.3V and small current DC20mA parameter indicators, and will not produce dangerous energy accumulation points.

[0058] Through the above method, the present invention can be directly installed in the dangerous area inside the oil tank, and directly contact measurement and control.

[0059] 2. The structure of the present invention is in direct contact with the kerosene inside the oil tank, and can continuously, automatically, safely and reliably detect and feedback the changes in the kerosene level in the moving state.

[0060] The aircraft fuel tank 27 may have different motion posture angles during operation. The device must automatically and quickly sense the kerosene liquid level in various motion states during the changes in the aircraft fuel tank's oil level state, including pitch, roll (inverted flight), yaw, etc., and reliably and timely transmit the kerosene liquid level changes in motion to the electronic signal processing module 11. The electronic signal processing module 11 controls the explosion-proof micro solenoid valve 3 and the diaphragm gas driver 14 according to the circuit high and low level conversion to achieve accurate flow of the measured gas, and the photoelectric conversion of the photoelectric signal conversion module 9 realizes the measurement of the oxygen concentration data inside the fuel tank without being affected by the complex changes in the kerosene liquid level in motion.

[0061] like Figure 8As shown, states A and B are schematic diagrams of tilt measurement at different angles, state C is a schematic diagram of horizontal measurement, state D is a schematic diagram of normal state measurement, and state E is a schematic diagram of inverted measurement. In states A, B, and D, the explosion-proof optical oil level detector 1 is always in the lowest position of the method / device, and will be the first to detect whether the kerosene level inside the oil tank will exceed the explosion-proof optical oil level detector 1, generate a high-low level conversion of the liquid level signal, and output a high level through the electronic signal processing module 11 to close the explosion-proof micro-solenoid valve 3 and the diaphragm gas driver 14, while the measurement of the photoelectric signal conversion module 9 will not be affected and continue to measure. In state C, the explosion-proof optical oil level detector 1 is in a parallel position with the kerosene level, and will still be the first to detect whether the kerosene level inside the oil tank will exceed the optical oil level detector 1, generate a high-low level conversion of the liquid level signal, and output a high level through the electronic signal processing module 11 to close the explosion-proof micro-solenoid valve 3 and the diaphragm gas driver 14, while the measurement of the photoelectric signal conversion module 9 will not be affected and continue to measure. In state E, although the explosion-proof optical oil level detector 1 is in the highest position, since the oil tank is in an inverted state, the entire device and the explosion-proof optical oil level detector 1 are submerged in kerosene, and the electronic signal processing module 11 outputs a high level to close the explosion-proof micro solenoid valve 3 and the diaphragm gas driver 14, while the measurement of the photoelectric signal conversion module 9 will not be affected and continues to measure.

[0062] In all A, B, C, D, and E states, even during the rotation of the oil tank, due to the delay in the high-low level conversion time of the electronic signal processing module 11, a very small amount of kerosene will pass through the explosion-proof micro solenoid valve 3 during the action gap of the explosion-proof micro solenoid valve 3 and enter the 3D printed kerosene particle filter cavity 5 inside the device, and will also be quickly absorbed by the kerosene absorption filter material inside the 3D printed kerosene particle filter cavity 5 and will not enter the precision gas filter isolator 7, and the measurement of the photoelectric signal conversion module 9 will not be affected and will continue to measure.

[0063] Through the above method, the present invention can safely realize continuous measurement of the oil tank in various motion states.

Claims

1. An explosion-proof full-state optical principle oxygen concentration measuring device, characterized in that: The invention comprises an explosion-proof optical oil level detector (1) extending into an aircraft fuel tank (27), wherein an air inlet of the explosion-proof optical oil level detector (1) is located above the kerosene liquid level in the aircraft fuel tank, and an air outlet of the explosion-proof optical oil level detector (1) is located in the kerosene in the aircraft fuel tank. An explosion-proof micro solenoid valve (3) is also arranged inside the explosion-proof optical oil level detector (1), and the explosion-proof micro solenoid valve (3) is also connected to a 3D printed kerosene particle filter cavity (5), and the top of the 3D printed kerosene particle filter cavity (5) is connected to a precision gas filter isolator (7). The explosion-proof micro solenoid valve (3) is connected to an electronic signal processing module (11), a power supply and signal output module (16) in sequence, and the power supply and signal output module (16) are connected to the electronic signal processing module (11), ... The signal output module (16) is connected to the signal electrical connector (17), and the signal electrical connector (17) is sealed and connected through the device housing, so that the device as a whole is connected to the external power supply signal output. The electronic signal processing module (11) is connected to the photoelectric signal conversion module (9), the laser light emitting LD device (10), and the photoelectric detection diode (8) in sequence. The photoelectric signal conversion module (9) is also connected to the A / D conversion module. The electronic signal processing module (11) is also connected to the explosion-proof optical oil level detector (1) and the diaphragm gas driver (14). The lower part of the structural housing is connected to the inside of the aircraft fuel tank through a KF40 vacuum sealing joint (2). The explosion-proof micro solenoid valve (3) is provided with an explosion-proof micro solenoid valve inlet (19) and an explosion-proof micro solenoid valve outlet (20); the explosion-proof micro solenoid valve inlet (19) is connected to the air inlet of the explosion-proof optical oil level detector (1) through an inlet joint (18); the explosion-proof micro solenoid valve outlet (20) is connected to the 3D printed kerosene particle filter cavity (5) through a 3D printed filter cavity inlet (21); the top of the 3D printed kerosene particle filter cavity (5) is connected to the sealed isolated optical measurement cavity inlet (23) of the sealed isolated optical measurement cavity (12) through a 3D printed filter cavity outlet (22); the sealed isolated optical measurement cavity (12) is also provided with a sealed isolated optical measurement cavity outlet (24); the sealed isolated optical measurement cavity (12) is provided with a sealed isolated optical measurement cavity outlet (24); The isolated optical measuring cavity (12) is also connected to a diaphragm gas driver outlet (25) provided on the diaphragm gas driver (14). The diaphragm gas driver (14) is placed on the diaphragm gas driver base (13). The hose (4) passes through the diaphragm gas driver outlet (25), the sealed isolated optical measuring cavity outlet (24), and the oil return tank gas connector (26) in sequence and is then connected to the gas outlet of the explosion-proof optical oil level detector (1). A one-way check valve (6) is also provided on the hose (4) between the sealed isolated optical measuring cavity outlet (24) and the oil return tank gas connector (26) for sealing and isolation. A sealing ring (15) is also provided between the above components for sealing.

2. A measurement method of an explosion-proof full-state optical principle oxygen concentration measurement device, characterized in that: Based on the explosion-proof grade full-state optical principle oxygen concentration measuring device according to claim 1, it is specifically implemented according to the following steps: Step 1: First, install and fix the explosion-proof optical oil level detector (1) in direct contact with the dangerous explosion-proof space area inside the oil tank through the KF40 vacuum sealing joint (2) to detect the change of kerosene level; Step 2: When the explosion-proof optical oil level detector (1) installed inside the oil tank is not submerged by the kerosene level, the electronic signal processing module (11) controls the explosion-proof micro solenoid valve (3) and the diaphragm gas driver (14) to be in an open state; Step 3: The gas to be measured located in the dangerous area inside the oil tank is driven by the diaphragm gas driver (14) and passes through the gas inlet connector (18), the explosion-proof micro solenoid valve (3), the 3D printed filter chamber inlet (21), the 3D printed filter chamber outlet (22), and then passes through the sealed isolated optical measurement chamber inlet (23) to enter the sealed isolated optical measurement chamber (12); Step 4: Inside the sealed isolated optical measurement cavity (12), the pure gas filtered by the precision gas filter isolator (7) is measured for optical intensity attenuation through the laser light emitting LD device (10) and the photoelectric detection diode (8), and the photoelectric signal conversion module (9) transmits the measured original optical intensity signal to the electronic signal processing module (11), and finally the electronic signal processing module (11) outputs the converted gas concentration data through the signal electrical connector (17); Step 5: The filtered and measured gas is then passed through the sealed isolation optical measurement cavity outlet (24), the diaphragm gas driver outlet (25), and finally through the fuel tank return gas connector (26) to return the original measured gas to the aircraft fuel tank (27). At this point, the oxygen concentration content of the atmosphere inside the fuel tank in a dangerous environment is measured.

3. The measuring method of the explosion-proof full-state optical principle oxygen concentration measuring device according to claim 2 is characterized in that: The signal electrical connector (17), i.e., the aviation plug, in the power and signal output module (16) provides an external DC28V power supply which is converted into DC5V and DC3.3V by a DC / DC power converter and fed to the electronic signal processing module (11) and the photoelectric signal conversion module (9) at the same time, thereby realizing power supply and signal transmission of the entire device.

4. The measuring method of the explosion-proof full-state optical principle oxygen concentration measuring device according to claim 2 is characterized in that: The laser light emitting LD device (10) emits pulsed light beams of the same wavelength and light intensity at intervals under the control of the optoelectronic A / D single chip microcomputer, passes through sealed gas chambers of different concentrations, and generates light pulses of different light intensity attenuation. After being received by the photoelectric detection diode (8), the light pulses of different light intensities are converted into electrical pulses of different voltages. After the optoelectronic A / D single chip microcomputer measures and digitizes the electrical pulses of different voltages, the original measurement data is output to the electronic signal processing module (11) via a TTL level UART interface.

5. The measuring method of the explosion-proof full-state optical principle oxygen concentration measuring device according to claim 2 is characterized in that: The functions of the electronic signal processing module (11) include data level conversion and I / O port control.

6. The measuring method of the explosion-proof full-state optical principle oxygen concentration measuring device according to claim 5 is characterized in that: The data level conversion specifically includes: the electronic signal processing module (11) converts the TTL level UART interface signal from the photoelectric signal conversion module (9) into an RS485 level signal, and transmits it to the remote client data receiver through the signal electrical connector (17).

7. The measuring method of the explosion-proof full-state optical principle oxygen concentration measuring device according to claim 5 is characterized in that: The I / O port control is specifically as follows: the electronic signal processor determines the kerosene level signal of the explosion-proof optical oil level detector (1) through the high and low level changes of the I / O pin; if the explosion-proof optical oil level detector (1) is submerged in kerosene in the oil tank, the high and low levels of the input I / O pin of the electronic signal processor are reversed, and the output I / O pin of the electronic signal processor outputs high and low levels, thereby controlling the explosion-proof micro solenoid valve (3) and the diaphragm gas driver (14) to open or close.

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