A method, device and apparatus for measuring aerosol concentration

Abstract

The present invention relates to an aerosol concentration measurement method, device and equipment. An aerosol concentration measurement method comprises the following steps: controlling an initial light intensity signal I0 to the aerosol powder; passing through the aerosol powder to be measured, the initial light intensity signal I0 is attenuated to obtain an attenuated detection light intensity signal I m ; According to the attenuation detection light intensity signal I m Calculate the transmittance #imgabs0# generated by the initial light intensity signal I0 on the aerosol powder to be tested, wherein the transmittance #imgabs1# is a preset detection light intensity signal I b and the attenuated detection light intensity signal I m According to the transmittance #imgabs2#, the aerosol powder concentration M is obtained through the relationship function v The present invention can accurately measure the aerosol concentration, and reduce the impact of aerosol powder adhesion and changes in test environment factors, thereby reducing the problems of large fluctuations in measurement values ​​and large errors.

Description

Technical Field

[0001] The present invention relates to the technical field of aerosol concentration detection, and in particular to an aerosol concentration measurement method, an aerosol concentration measurement device, and an aerosol concentration measurement equipment. Background Art

[0002] New aerosol fire extinguishing agents have been increasingly widely used due to their environmental friendliness, high fire extinguishing efficiency, and light weight. In order to evaluate whether a new aerosol fire extinguishing system in a protected space, especially in a large vehicle such as an aircraft power cabin, can effectively play a role in fire extinguishing protection, it is necessary to release the fire extinguishing agent into the space to be protected, and simultaneously record the volume concentration of the aerosol fire extinguishing agent at representative locations in each area of ​​the space to be protected through a measurement system. The measured concentration value of the aerosol fire extinguishing agent must be higher than a known effective fire extinguishing concentration, which refers to a concentration sufficient to extinguish a fire that may occur in the protected space within a certain period of time.

[0003] In the existing measurement system, a screw feeder is used to generate powder, but the unevenness caused by the combination with high-speed inert airflow seriously affects its measurement accuracy, and the calibration process of a single-channel sensor is too cumbersome; or the dust concentration is calculated by inversion of dust transmitted light, but the randomness of dust particles cannot avoid the impact of the measurement accuracy on the measurement accuracy; in order to increase the ratio of transmitted light intensity to obtain highly reliable transmitted light and change the optical path of the measuring probe at different positions to improve the measurement accuracy, the parabolic focusing lens inside the threaded fiber optic probe is difficult to process, which increases the cost and is difficult to implement. Summary of the invention

[0004] Based on this, it is necessary to provide an aerosol concentration measurement method, an aerosol concentration measurement device, and an aerosol concentration measurement device to address the problems in the prior art of high difficulty in measuring equipment processing, large fluctuations in aerosol concentration measurement values, and large errors.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for measuring aerosol concentration, which is used to measure the concentration value of an aerosol powder to be measured; the aerosol powder concentration measurement method comprises the following steps:

[0007] Controlling an initial light intensity signal I0 to the aerosol powder;

[0008] The aerosol powder to be tested is passed through, and the initial light intensity signal I0 is attenuated to obtain the attenuated detection light intensity signal I m ;

[0009] According to the attenuation detection light intensity signal I mCalculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b and the attenuated detection light intensity signal I m The ratio of

[0010] According to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: Among them, a is the dust layer influence factor, k is the extinction factor, and b is the ambient light interference factor.

[0011] Furthermore, the preset detection light intensity signal I b The setting method includes the following steps:

[0012] The initial detection light intensity signal I after the initial light intensity signal I0 is attenuated in the measurement space without aerosol dust b .

[0013] Furthermore, the design method of the relationship function comprises the following steps:

[0014] Injecting aerosol powder with an aerosol powder concentration of c into the aerosol dust-free measurement space to obtain a fixed concentration measurement space;

[0015] Obtaining the dust contamination transmittance G of the fixed concentration measurement space after being contaminated by the aerosol powder having the aerosol powder concentration c;

[0016] According to the ambient light intensity signal I ∞ , the initial detection light intensity signal I b and the attenuated detection light intensity signal I m Calculate ideal transmittance

[0017] The ideal transmittance is established according to the Lambert-Beer law and the aerosol powder concentration M v The ideal relationship function: Among them, K ext is the extinction coefficient of aerosol powder, L is the effective optical path for aerosol powder measurement;

[0018] According to the actual transmittance Adjust the ideal relationship function to get the actual relationship expression:

[0019] Simplify the actual relational expression to get the relational function: Among them, the dust layer influence factor Extinction factor k = -K ext L, ambient light interference factor

[0020] Furthermore, the method for calculating the dust contamination transmittance G comprises the following steps:

[0021] Calculate the accumulated mass M of dust contamination in the fixed concentration measurement space according to the measurement time t powdrr :

[0022] Calculate the dust contamination transmittance G:

[0023] The present invention also includes an aerosol concentration measuring device, which is used to measure the concentration value of aerosol powder to be measured; the device includes:

[0024] An initial light intensity signal control unit, which is used to control an initial light intensity signal I0 to the aerosol powder to be tested;

[0025] The attenuated detection light intensity signal calculation unit is used to obtain the attenuated detection light intensity signal I after the initial light intensity signal I0 is attenuated through the aerosol powder to be tested. m ;

[0026] A transmittance calculation unit, which is used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m The ratio of

[0027] The aerosol powder concentration calculation unit is used to calculate the aerosol powder concentration according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: Among them, a is the dust layer influence factor, k is the extinction factor, and b is the ambient light interference factor.

[0028] The present invention also includes an aerosol concentration measuring device, which is used to measure the concentration value of the aerosol powder to be measured; the device includes:

[0029] A laser detection unit, which is used to provide an initial light intensity signal I0;

[0030] The sensor is used to collect the initial light intensity signal I0 and obtain the attenuated detection light intensity signal I after the initial light intensity signal I0 is attenuated by the aerosol powder to be tested. m ;

[0031] The controller is used to control the laser detection unit to transmit the initial light intensity signal I0 to the aerosol powder to be detected; and also controls the sensor to collect the initial light intensity signal I0 and obtain the attenuated detection light intensity signal I0 after the attenuation of the aerosol powder to be detected. m ; Also used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m ratio; also used according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: a is the dust layer influence factor, k is the extinction factor, and b is the ambient light interference factor.

[0032] Furthermore, the controller further comprises a display unit for displaying the aerosol powder concentration M v .

[0033] Furthermore, the laser detection unit includes a shell, and a first light intensity emission channel, a first light intensity measurement channel and a second light intensity measurement channel are arranged inside the shell. The first light intensity emission channel and the first light intensity measurement channel are arranged in parallel and are not connected to each other, and the second light intensity measurement channel is perpendicular to the first light intensity emission channel and is connected at the intersection; the first light intensity emission channel is coaxially provided with a light source fiber SMA interface, a third collimating lens, a beam splitter, a first collimating lens and a laser diode, and the normal of the beam splitter is at an angle of 45° with the axis of the first light intensity emission channel; the first light intensity measurement channel is coaxially provided with a detection fiber SMA interface, a fourth collimating lens, a fifth collimating lens, and a second photosensitive diode, and the detection fiber SMA interface is adjacent to and flush with the light source fiber SMA interface; the second light intensity measurement channel is coaxially provided with a second collimating lens and a first photosensitive diode, and the second collimating lens is adjacent to the beam splitter.

[0034] Furthermore, the initial light intensity signal I0 is emitted by the laser diode and is divided into a first initial light intensity signal and a second initial light intensity signal by a beam splitter. The first initial light intensity signal is emitted along a first light intensity emission channel to measure the concentration value of the aerosol powder to be measured. The second initial light intensity signal enters a second light intensity measurement channel to monitor the initial light intensity signal I0. The light intensity value ratio of the first initial light intensity signal and the second initial light intensity signal is 9:1.

[0035] Furthermore, a temperature control component is installed on the outer wall of the shell to monitor the surface temperature of the shell.

[0036] The technical solution provided by the present invention has the following beneficial effects:

[0037] This measurement method can accurately measure aerosol concentration, and by reducing the impact of aerosol powder adhesion and changes in test environmental factors, it can reduce the problems of large fluctuations in measurement values ​​and large errors. This measuring equipment can reduce the difficulty of processing while ensuring high measurement accuracy, eliminating the need for repeated operations and simplifying measurement operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a flow chart of the aerosol concentration measurement method of the present invention;

[0039] Figure 2 Based on Figure 1 Schematic diagram of the structure of the optical fiber sensor;

[0040] Figure 3 Based on Figure 2 Structural diagram of the measurement principle;

[0041] Figure 4 Based on Figure 3 Schematic diagram of the empirical relationship between aerosol concentration and transmittance fitted by the measurement principle;

[0042] Figure 5 Schematic diagram of the external structure of the laser detection unit;

[0043] Figure 6 Based on Figure 5 Schematic diagram of the internal structure of the laser detection unit;

[0044] Figure 7 It is the measurement principle diagram of the measurement controller and the optical fiber sensor;

[0045] Figure 8 It is a structural schematic diagram of the aerosol concentration measuring device of the present invention;

[0046] Fig. 9 Based on Figure 8 The connection structure diagram of the measurement controller and the optical fiber sensor;

[0047] Fig.10 Based on Fig. 9 The structural diagram of the corresponding measurement control system and optical fiber sensor system;

[0048] Fig.11 Based on Figure 8 Equipment operation flow chart;

[0049] Fig.12 Based on Figure 8 Equipment calibration operation flow chart;

[0050] Fig.13 Based on Fig.10 Schematic diagram of the structure of the equipment measured in the protected space;

[0051] Main component symbols

[0052] 10. Shell; 100. First light intensity emission channel; 200. First light intensity measurement channel; 300. Second light intensity measurement channel; 101. Detection fiber SMA interface; 102. Light source fiber SMA interface; 103. Third collimating lens; 104. Beam splitter; 105. Second collimating lens; 106. First photodiode; 107. First collimating lens; 108. Laser diode; 109. Second photodiode; 110. Fifth collimating lens; 111. Fourth collimating lens; 20. Fiber optic sensor; 14. Measurement transmission fiber; 141. Light source fiber; 142. Detection fiber; 145. Fiber optic coupler; 146. Probe fiber bundle; 15. Measurement fiber optic probe.

[0053] The above description of the main component symbols is combined with the accompanying drawings and specific implementation methods to further illustrate the present invention in detail. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] like Figure 1 As shown, this embodiment provides an aerosol concentration measurement method, comprising the following steps:

[0056] S100. Controlling an initial light intensity signal I0 to the aerosol powder;

[0057] S200. The initial light intensity signal I0 is attenuated to obtain an attenuated detection light intensity signal I through the aerosol powder to be tested. m ;

[0058] S300. Detecting the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b and the attenuated detection light intensity signal I m The ratio of

[0059] S400. According to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: Among them, a is the dust layer influence factor, k is the extinction factor, and b is the ambient light interference factor.

[0060] When the above method is implemented, the attenuated detection light intensity signal I m The data is collected using a sensor, and an optical fiber sensor 20 can be used to measure the aerosol concentration. Taking the optical fiber sensor 20 as an example, a specific implementation is provided.

[0061] like Figure 2 As shown, the optical fiber sensor 20 mainly includes a measuring transmission optical fiber 14 and a measuring optical fiber probe 15, wherein the measuring transmission optical fiber 14 includes a light source optical fiber 141, a detection optical fiber 142 and a probe optical fiber bundle 146. The light source optical fiber 141 and the detection optical fiber 142 are connected to the probe optical fiber bundle 146 through an optical fiber coupler 145, and the front end of the probe optical fiber bundle 146 is connected to the measuring optical fiber probe 15. For the convenience of bunching, the optical fiber sensor 20 is installed in an optical fiber chassis, which also includes an optical fiber buncher and a probe fixture. In specific applications, the number of cores of the light source optical fiber 141 is 1, and the core diameter is 600um, and the number of cores of the detection optical fiber 142 is 6, and the core diameter is 200um. The light source optical fiber 141 and the detection optical fiber 142 are in the probe optical fiber bundle 146 through the optical fiber coupler 145, the core of the light source optical fiber 141 is located in the center, and the core of the detection optical fiber 142 is evenly arranged around. In some embodiments, the measurement transmission optical fiber 14 is relatively long (for example, when testing a protected aircraft engine compartment, the measurement transmission optical fiber length needs to be 15m), which is not conducive to the development of experimental tests. The purpose of the fiber optic bundler is to better bundle the longer measurement transmission optical fiber.

[0062] like Figure 3As shown, the rear end of the measuring optical fiber probe 15 is connected to the front end of the probe optical fiber bundle 146, and the front end of the measuring optical fiber probe 15 is a concave reflector. The initial light intensity signal I0 emitted by the probe optical fiber bundle 146 has a certain emission angle, and after passing through a certain concentration of aerosol in the measuring space V, it undergoes the first attenuation, and is converged and reflected on the front concave reflector. After passing through a certain concentration of aerosol in the measuring space V again, it undergoes the second attenuation and finally converges at the front end of the probe optical fiber bundle 146. Before measuring the powder concentration, there is no powder contamination in front of the optical window, and the detection light intensity signal I0 received by the receiving end is b The factors affecting it can be expressed as:

[0063] I b =τ w I0+I ∞ , where τ w is the transmittance of the initial light intensity signal I0 after being emitted by the concave reflector, I ∞ It is the ambient light intensity signal.

[0064] During the powder concentration measurement process, at the i-th moment, the optical window is contaminated by powder, and the thickness of the contaminated powder gradually increases. The aerosol powder contamination layer in front of the probe fiber bundle 146 is recorded as α, and the aerosol powder contamination layer in front of the concave reflector is recorded as β. The attenuated detection light intensity signal I received by the receiving end m The factors affecting it can be expressed as: and They are the transmittance of the initial light intensity signal I0 after passing through the aerosol powder contamination layer in front of the probe optical fiber bundle 146 and the aerosol powder contamination layer in front of the concave reflector. is the transmittance of the initial light intensity signal I0 after passing through a certain concentration of aerosol in the measurement space V. By analyzing the causes of the dust layer, it can be seen that the change rate of the dust layer thickness is mainly affected by the dust concentration c and the measurement time t during the measurement process. For the control of the dust concentration c, an aerosol generating device can be used to generate the required aerosol powder, and the accumulation mass of the aerosol powder contamination layer is expressed as M powder , then the expression of the function is

[0065] The transmittance of the measured light through the aerosol powder contamination layer is inversely proportional to the stacking mass of the aerosol powder contamination layer. The transmittance G of the initial light intensity signal I0 after passing through the aerosol powder contamination layer in front of the probe optical fiber bundle 146 and the aerosol powder contamination layer in front of the concave reflector can be expressed as:

[0066] Eliminates the influence of aerosol powder contamination on the measurement results. The ideal transmittance of aerosol powder The expression is:

[0067] According to the Beer-Lambert law, the ideal transmittance of aerosol powder Relationship with powder particle concentration: Where K ext is the extinction coefficient of aerosol powder, L is the effective optical path, M v is the aerosol concentration to be measured. In the actual measurement process, the light intensity signal received by the probe fiber bundle 146 includes the attenuation signal of the ambient light and the aerosol powder contamination layer. Then in the actual measurement process, the transmittance obtained is The expression is:

[0068] The transmittance Substitute the ideal transmittance into the expression The theoretical solution is calculated from the expression of , and the relationship model between transmittance and powder concentration in high-concentration powder measurement is established. With concentration M v The expression is:

[0069] We can simplify accordingly and get Among them, the dust layer influence factor Extinction factor k = -K ext L, ambient light interference factor like Figure 4 As shown, Rewrite it as function y = ae kx +b is fitted to establish a calibration curve of concentration value and light intensity value. In actual operation, sodium bicarbonate aerosol fire extinguishing agent is calibrated and tested, and the results show that the maximum indication error of the measurement is less than 10%.

[0070] The present embodiment also provides an aerosol concentration measuring device, which implements the above-mentioned aerosol concentration measuring method when working, and the device includes: an initial light intensity signal control unit, which is used to control an initial light intensity signal I0 to the aerosol powder to be measured; an attenuated detection light intensity signal calculation unit, which is used to pass through the aerosol powder to be measured, and obtain an attenuated detection light intensity signal I0 after the initial light intensity signal I0 is attenuated. m ; A transmittance calculation unit, which is used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m aerosol powder concentration calculation unit, which is used according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: The device has high measurement accuracy, can be calibrated, has good repeatability, can adapt to changes in test environmental factors, can be used to analyze whether the aerosol powder concentration meets the requirements, and has broad application prospects.

[0071] This embodiment also provides an aerosol concentration measurement device, which can implement the above-mentioned aerosol concentration measurement method when working, and the device includes a laser detection unit, which is used to provide an initial light intensity signal I0; a sensor, which is used to collect the initial light intensity signal I0 and obtain an attenuated detection light intensity signal I0 after attenuation by the aerosol powder to be measured. m ; A controller for controlling the laser detection unit to transmit the initial light intensity signal I0 to the aerosol powder to be tested; and also controlling the sensor to collect the initial light intensity signal I0 and obtain the attenuated detection light intensity signal I after the attenuation of the aerosol powder to be tested. m ; Also used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m ratio; also used according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is:

[0072] like Figure 5 and Figure 6As shown, the sensor can be a fiber optic sensor 20, and the laser detection unit includes a housing 10, a detection fiber SMA interface 101, a light source fiber SMA interface 102, a laser diode 108, a first collimating lens 107, a beam splitter 104, a first photosensitive diode 106, a second collimating lens 105, a third collimating lens 103, a fourth collimating lens 111, a fifth collimating lens 110, a second photosensitive diode 109, and a temperature component. Among them, the laser diode 108, the first photosensitive diode 106 and the second photosensitive diode 109 are connected to the driving control circuit; and also include a first light intensity emission channel 100, a first light intensity measurement channel 200 and a second light intensity measurement channel 300. The first light intensity emission channel 100 and the first light intensity measurement channel 200 are arranged in parallel and are not connected to each other. The second light intensity measurement channel 300 is perpendicular to the first light intensity emission channel 100 and the measurement channels are connected. The first light intensity emission channel 100, the first light intensity measurement channel 200 and the second light intensity measurement channel 300 are defined along axes A, B and C respectively; the laser diode 108 and the first collimating lens 107, the third collimating lens 103 and the light source fiber SMA interface 102 are coaxially defined along the axis S1. The beam splitter 104 is between the first collimating lens 107 and the third collimating lens 103, and the normal direction is at an angle of 45° with the axis A. Along the position of the beam splitter 104, the second collimating lens 105 and the first photosensitive diode 106 are arranged along the axis C, and the normal direction of the beam splitter 104 is at an angle of 45° with the axis C. The second photodiode 109 , the fifth collimating lens 110 , the fourth collimating lens 111 and the detection optical fiber SMA interface 101 are arranged along the axis B in sequence.

[0073] In actual application, the laser diode 108 uses visible light with a wavelength of 650nm, the power of the laser diode 108 is 40mw, and the fluctuation range of the light source is less than ±0.1%. The first photosensitive diode 106 mainly monitors the initial light intensity, and the second photosensitive diode 109 mainly monitors the detection light intensity. The initial light intensity signal emitted by the laser diode 108 is divided into two by the beam splitter 104, and the ratio of the light intensity values ​​entering the first photosensitive diode 106 and the light source optical fiber 141 is 1:9. It can not only ensure the output power of the initial light intensity signal in the light source optical fiber 141, but also monitor and correct the initial light intensity signal. The shell 10 is usually made of light-absorbing material, and the temperature control component located below the shell 10 can ensure that components such as diodes reduce the impact of temperature changes. The temperature control component can use a temperature control switch.

[0074] In actual operation, the laser detection unit can also be directly incorporated into the controller to form a measurement controller 19, which is composed of a laser detection unit, a data processing and acquisition unit, and a control and display unit; Figure 7As shown, the laser detection unit is used to generate an initial light intensity signal for detecting aerosol concentration and monitor the initial light intensity signal, and at the same time monitor the attenuated detection light signal after passing through a certain concentration of aerosol, and finally convert the light intensity signal into an electrical signal; the data processing and acquisition unit is connected to the laser detection unit, and performs data processing and acquisition on the electrical signal of the laser detection unit, and converts the electrical signal into a concentration value reflecting the aerosol concentration; the control and display unit is respectively connected to the data processing and acquisition unit and the laser detection unit, in addition to realizing the control of the two units, it also displays the concentration value calculated by the data processing and acquisition unit in real time. The data processing and acquisition unit includes a signal processing module 3 and a data acquisition card 4. The control and display unit includes a control module 5 and a display 12. As shown Figure 8 As shown, the measurement controller 19 is installed in the measurement chassis, and is also equipped with corresponding power switch 8, constant current power supply 9, device switch 11, light source switch 2 and cooling fan 6. The opening sequence is to turn on the power switch 8 first, then turn on the device switch 11, and then turn on the light source switch 2 after the device is turned on and stabilized; the closing sequence is to turn off the light source switch 2 first, wait for the light source to dissipate heat, and then turn off the device switch 11 and the power switch 8 in sequence.

[0075] like Fig. 9 and Fig.10 As shown, the aerosol concentration measurement equipment can be expanded to realize real-time monitoring of multiple measurement points of aerosol concentration in a protected space such as an aircraft engine compartment. According to the requirements of the measurement points, multiple groups of measurement controllers 19 and the same number of optical fiber sensors 20 are set to form corresponding measurement control systems 30 and optical fiber sensor systems 40 respectively.

[0076] like Fig.11 As shown, during the experimental stage, the operation steps of the equipment are as follows:

[0077] Step S1: calibrating the aerosol concentration measuring device according to the aerosol powder to be measured;

[0078] Step S2: The measuring optical fiber probe 15 is fixedly placed at a measuring point in the protected space;

[0079] Step S3: The concentration value can be displayed in real time on the display on the measurement controller, and the measurement data can be recorded.

[0080] like Fig.12 As shown, the calibration steps of the aerosol concentration measuring equipment are as follows:

[0081] Step S11: for a specific aerosol test, prepare the same powder aerosol sample and place the sample in an aerosol concentration generating device;

[0082] Step S12: according to the aerosol concentration measurement range required for the test, the aerosol concentration generating device is set to a corresponding generation concentration according to the measurement range;

[0083] Step S13: the optical fiber sensor is placed in the aerosol concentration generating device for calibration, the calibration device records the generated concentration value, and the optical fiber sensor records the change of the light intensity value;

[0084] Step S14: Correspond the concentration value generated by the aerosol concentration generating device to the light intensity value monitored in real time, and use the function y=ae kx +b is fitted to establish a calibration curve between concentration value and light intensity value;

[0085] Step S5: The calibration curve is stored and recorded in the measurement controller.

[0086] The measuring device can reduce the processing difficulty while ensuring high measurement accuracy, eliminating the need for repeated operations and simplifying the measurement operation. Fig.13 This is a schematic diagram of the structure of the device in a protected space.

[0087] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for measuring aerosol concentration, which is used to measure the concentration value of aerosol powder to be measured; characterized in that: The aerosol powder concentration measurement method comprises the following steps: Controlling an initial light intensity signal I0 to the aerosol powder; The aerosol powder to be tested is passed through, and the initial light intensity signal I0 is attenuated to obtain the attenuated detection light intensity signal I m ; According to the attenuation detection light intensity signal I m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b and the attenuated detection light intensity signal I m The ratio of I b is the initial detection light intensity signal after the initial light intensity signal I0 decays in the measurement space without aerosol dust; According to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: Among them, a is the dust layer impact factor, G is the dust contamination transmittance, I ∞ is the ambient light intensity signal; k is the extinction factor, k = -K ext L, K ext is the extinction coefficient of aerosol powder, L is the effective optical path of aerosol powder measurement; b is the ambient light interference factor, The calculation method of dust contamination transmittance G includes the following steps: Calculate the accumulated mass M of dust contamination in the fixed concentration measurement space according to the measurement time t powder : Calculate the dust contamination transmittance G:

2. The aerosol concentration measurement method according to claim 1, characterized in that: The design method of the relationship function comprises the following steps: Injecting aerosol powder with an aerosol powder concentration of c into the aerosol dust-free measurement space to obtain a fixed concentration measurement space; Obtaining the dust contamination transmittance G of the fixed concentration measurement space after being contaminated by the aerosol powder having the aerosol powder concentration c; According to the ambient light intensity signal I ∞ , the initial detection light intensity signal I b and the attenuated detection light intensity signal I m Calculate ideal transmittance The ideal transmittance is established according to the Lambert-Beer law and the aerosol powder concentration M v The ideal relationship function: According to the actual transmittance Adjust the ideal relationship function to get the actual relationship expression: Simplify the actual relational expression to get the relational function: Among them, the dust layer influence factor Extinction factor k = -K ext L, ambient light interference factor 3. An aerosol concentration measuring device, which is used to measure the concentration value of aerosol powder to be measured; characterized in that: The aerosol concentration measuring device comprises: An initial light intensity signal control unit, which is used to control an initial light intensity signal I0 to the aerosol powder to be tested; The attenuated detection light intensity signal calculation unit is used to obtain the attenuated detection light intensity signal I after the initial light intensity signal I0 is attenuated through the aerosol powder to be tested. m ; A transmittance calculation unit, which is used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m The ratio of I b is the initial detection light intensity signal after the initial light intensity signal I0 decays in the measurement space without aerosol dust; The aerosol powder concentration calculation unit is used to calculate the aerosol powder concentration according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: Among them, a is the dust layer impact factor, G is the dust contamination transmittance, I ∞ is the ambient light intensity signal; k is the extinction factor, k = -K ext L, K ext is the extinction coefficient of aerosol powder, L is the effective optical path of aerosol powder measurement; b is the ambient light interference factor, The calculation method of dust contamination transmittance G includes the following steps: Calculate the accumulated mass M of dust contamination in the fixed concentration measurement space according to the measurement time t powder : Calculate the dust contamination transmittance G:

4. An aerosol concentration measuring device, which is used to measure the concentration value of aerosol powder to be measured; characterized in that: The aerosol concentration measuring device comprises: A laser detection unit, which is used to provide an initial light intensity signal I0; The sensor is used to collect the initial light intensity signal I0 and obtain the attenuated detection light intensity signal I after the initial light intensity signal I0 is attenuated by the aerosol powder to be tested. m ; The controller is used to control the laser detection unit to transmit the initial light intensity signal I0 to the aerosol powder to be detected; and also controls the sensor to collect the initial light intensity signal I0 and obtain the attenuated detection light intensity signal I0 after the attenuation of the aerosol powder to be detected. m ; Also used to detect the light intensity signal I according to the attenuation m Calculate the transmittance generated by the initial light intensity signal I0 on the aerosol powder to be tested Among them, the transmittance is a preset detection light intensity signal I b And attenuation detection light intensity signal I m ratio; also used according to the transmittance The aerosol powder concentration M is obtained through the relationship function v , the relationship function is: a is the dust layer impact factor, G is the dust contamination transmittance, I ∞ is the ambient light intensity signal; k is the extinction factor, k = -K ext L, K ext is the extinction coefficient of aerosol powder, L is the effective optical path of aerosol powder measurement; b is the ambient light interference factor, I b is the initial detection light intensity signal after the initial light intensity signal I0 decays in the measurement space without aerosol dust; The calculation method of dust contamination transmittance G includes the following steps: Calculate the accumulated mass M of dust contamination in the fixed concentration measurement space according to the measurement time t powder : Calculate the dust contamination transmittance G:

5. The aerosol concentration measuring device according to claim 4, characterized in that: The controller also includes a display unit for displaying the aerosol powder concentration M v .

6. The aerosol concentration measuring device according to claim 4, characterized in that: The laser detection unit comprises a housing (10), wherein a first light intensity emission channel (100), a first light intensity measurement channel (200) and a second light intensity measurement channel (300) are arranged inside the housing (10), wherein the first light intensity emission channel (100) and the first light intensity measurement channel (200) are arranged in parallel and are not connected to each other, and the second light intensity measurement channel (300) is perpendicular to the first light intensity emission channel (100) and is connected at the intersection; and a light source optical fiber SMA interface (102), a third collimating lens (103), a beam splitter (104), a first collimating lens (107) and a laser diode ( 108), the normal of the beam splitter (104) and the axis of the first light intensity emission channel (100) form an angle of 45°; a detection optical fiber SMA interface (101), a fourth collimating lens (111), a fifth collimating lens (110), and a second photosensitive diode (109) are coaxially arranged in sequence in the first light intensity measurement channel (200), and the detection optical fiber SMA interface (101) and the light source optical fiber SMA interface (102) are adjacent to and flush with each other; a second collimating lens (105) and a first photosensitive diode (106) are coaxially arranged in the second light intensity measurement channel (300), and the second collimating lens (105) and the beam splitter (104) are adjacent to each other.

7. The aerosol concentration measuring device according to claim 6, characterized in that: The initial light intensity signal I0 is emitted by a laser diode (108) and is divided into a first initial light intensity signal and a second initial light intensity signal by a beam splitter (104). The first initial light intensity signal is emitted along a first light intensity emission channel (100) and is used to measure the concentration value of the aerosol powder to be measured. The second initial light intensity signal enters a second light intensity measurement channel (300) and is used to monitor the initial light intensity signal I0. The light intensity value ratio of the first initial light intensity signal and the second initial light intensity signal is 9:

1.

8. The aerosol concentration measuring device according to claim 6, characterized in that: The outer wall of the shell (10) is installed with a temperature control component for monitoring the surface temperature of the shell.

Images