CN108844870B - PM based on optical fiber structure10And PM2.5Probe instrument apparatus and system - Google Patents
PM based on optical fiber structure10And PM2.5Probe instrument apparatus and system Download PDFInfo
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Abstract
The invention provides a PM based on an optical fiber structure10And PM2.5A probe instrument apparatus and system comprising: the device comprises an optical signal generating unit, a detection array and an optical frequency conversion unit; the optical signal generating unit is connected with the detection array and used for generating optical signals and loading the optical signals to the detection array; the detection array is connected with the light frequency conversion unit and used for emitting light signals, receiving scattered light signals according to the particle scattering condition of the measurement area and sending the scattered light signals to the light frequency conversion unit; and the light frequency conversion unit is used for generating frequency signals according to the scattered light signals and acquiring the distribution of different particle diameters and environmental indexes in the atmosphere according to the frequency signals. The invention adopts the all-fiber design, has few optical discrete elements, high system reliability and small probe volume, is easy to lay in the environment and is more suitable for the current environment detection.
Description
Technical Field
The invention relates to an environmental PM10And PM2.5The technical field of testing, in particular to a PM based on an optical fiber structure10And PM2.5A probe instrument apparatus and system.
Background
With the large-scale construction of cities, dust pollution in the environment is increasingly serious. Among the various particulate contaminants, Particulate Matter (PM) having a diameter of less than 10 μm10) Referred to as inhalable particles. The inhalable particles not only have great influence on atmospheric visibility but also seriously threaten human health, PM2.5(particles less than 2.5 μm in diameter) are considered more hazardous as they are able to enter the human lung causing inflammation of the alveoli. And the plants have obvious functions of blocking, filtering and adsorbing dust, so that dust particles in the atmosphere can be effectively reduced in urban greening construction. This aspect of research has now progressed from individual plants to different plant communities for dust holding capacity. In order to measure PM near plant community more accurately in research10And PM2.5The spatial distribution and the change condition of the concentration need a detecting instrument with multi-position and real-time detection capability and a small probe volume, thereby being convenient to be arranged around the plant community.
However, most of the existing light scattering particle analyzers are handheld portable measuring instruments, which are inconvenient to arrange and cannot realize multi-position simultaneous detection, and only single-point measurement can be realized. And related academic research at home and abroad is mainly developed around improving the measurement precision of a single probe, and research aiming at solving the requirements of probe miniaturization and quasi-distributed measurement in the current engineering application is blank.
In summary, the objective disadvantage of the prior art is the lack of an instrument device for accurately measuring environmental indicators.
Disclosure of Invention
In view of the above, the present invention provides a PM based on an optical fiber structure10And PM2.5Probe apparatus and system by employing full lightThe fiber design reduces optical discrete components, improves system reliability, has small probe volume, is easy to lay in the environment, and is more suitable for the current environment detection.
In a first aspect, embodiments of the present invention provide a PM based on an optical fiber structure10And PM2.5A probe instrument apparatus comprising: the device comprises an optical signal generating unit, a detection array and an optical frequency conversion unit;
the optical signal generating unit is connected with the detection array and used for generating an optical signal and loading the optical signal to the detection array;
the detection array is connected with the optical frequency conversion unit and used for emitting the optical signals, receiving scattered light signals according to the particle scattering condition of the measurement area and sending the scattered light signals to the optical frequency conversion unit;
and the light frequency conversion unit is used for generating frequency signals according to the scattered light signals and acquiring the distribution of different particle diameters and environmental indexes in the atmosphere according to the frequency signals.
With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, where the apparatus further includes an optical fiber coupler, where the optical fiber coupler includes a first optical fiber coupler and a second optical fiber coupler, the probe array includes a plurality of probes, and the probes include transmitting optical fibers and receiving optical fibers.
With reference to the first possible implementation manner of the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, where the method further includes:
the first optical fiber coupler is respectively connected with the optical signal generating unit and the detection array, and is used for splitting the optical signal generated by the optical signal generating unit and loading the split optical signal to the detection array;
and the second optical fiber coupler is respectively connected with the detection array and the optical frequency conversion unit, and is used for carrying out wave combination on the scattered light signals sent by the detection array and sending the combined scattered light signals to the optical frequency conversion unit.
With reference to the second possible implementation manner of the first aspect, the embodiment of the present invention provides a third possible implementation manner of the first aspect, where the optical signal generating unit includes a laser, an intensity modulator, and a frequency modulated continuous wave FMCW signal source, and the optical frequency converting unit includes a photodetector, a multiplier, a filter, and a fourier transform unit.
With reference to the third possible implementation manner of the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, where the method further includes:
the laser is connected with the intensity modulator and used for generating continuous light with unchanged light intensity and outputting the continuous light to the intensity modulator;
the FMCW signal source is connected with the intensity modulator and used for generating a first electric signal and loading the first electric signal to the intensity modulator;
the intensity modulator is connected with the detection array through the first optical fiber coupler and is used for modulating the continuous light into FMCW light signals according to the electric signals.
With reference to the fourth possible implementation manner of the first aspect, an embodiment of the present invention provides a fifth possible implementation manner of the first aspect, where the method further includes:
the photoelectric detector is respectively connected with the second optical fiber coupler and the multiplier, and is used for converting the combined scattered light signal into a second electric signal and sending the second electric signal to the multiplier;
the multiplier is respectively connected with the FMCW signal source and the filter and is used for multiplying the second electric signal and the first electric signal generated by the FMCW signal source to obtain a third electric signal;
the Fourier transform unit is connected with the multiplier through the filter and used for carrying out Fourier transform on the third electric signal to obtain different frequency signals so as to determine the particle diameter and the environmental index according to the pulse size and the number in the different frequency signals.
With reference to the first possible implementation manner of the first aspect, the present invention provides a sixth possible implementation manner of the first aspect, where the number of the first optical fiber couplers is 4, and the number of the second optical fiber couplers is 1.
With reference to the sixth possible implementation manner of the first aspect, the present invention provides a seventh possible implementation manner of the first aspect, wherein after the optical signal passes through the first fiber coupler, 4 sets of test light and 1 set of reference light are generated, the test light is loaded onto the emission fiber, and the reference light is loaded onto the second fiber coupler to be combined with the scattered optical signal.
With reference to the first possible implementation manner of the first aspect, the embodiment of the present invention provides an eighth possible implementation manner of the first aspect, wherein the probe includes a fiber optic ball lens.
In a second aspect, embodiments of the present invention provide a PM based on an optical fiber structure10And PM2.5A detection instrument system comprises the environment detection instrument device based on the optical fiber structure and also comprises an instrument handle.
The invention provides a PM based on an optical fiber structure10And PM2.5A probe instrument apparatus and system comprising: the device comprises an optical signal generating unit, a detection array and an optical frequency conversion unit; the optical signal generating unit is connected with the detection array and used for generating optical signals and loading the optical signals to the detection array; the detection array is connected with the light frequency conversion unit and used for emitting light signals, receiving scattered light signals according to the particle scattering condition of the measurement area and sending the scattered light signals to the light frequency conversion unit; and the light frequency conversion unit is used for generating frequency signals according to the scattered light signals and acquiring the distribution of different particle diameters and environmental indexes in the atmosphere according to the frequency signals. The invention adopts the all-fiber design, has few optical discrete elements, high system reliability and small probe volume, is easy to lay in the environment and is more suitable for the current environment detection.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a PM based on an optical fiber structure according to an embodiment of the present invention10And PM2.5A schematic view of a probing apparatus device;
FIG. 2 is a PM based on another optical fiber structure according to an embodiment of the present invention10And PM2.5A schematic view of a probing apparatus device;
FIG. 3 is a graph showing the relationship between particle diameter and forward scattered light flux according to an embodiment of the present invention;
FIG. 4 is a time-frequency curve diagram of a reference signal and a reflected signal according to an embodiment of the present invention;
FIG. 5 shows an optical fiber PM according to an embodiment of the present invention2.5And PM10A probe head of the detector.
Icon:
100-an optical signal generating unit; 110-a laser; 120-an intensity modulator; 130-a source of FMCW signals; 200-a detection array; 300-a light frequency conversion unit; 310-a photodetector; 320-a multiplier; 330-a filter; 340-a fourier transform unit; 400-a first fiber coupler; 500-second fiber coupler.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
With the large-scale construction of cities, dust pollution in the environment is increasingly serious. Among the various particulate contaminants, Particulate Matter (PM) having a diameter of less than 10 μm10) Referred to as inhalable particles. The inhalable particles not only have great influence on atmospheric visibility but also seriously threaten human health, PM2.5(particles less than 2.5 μm in diameter) are considered more hazardous as they are able to enter the human lung causing inflammation of the alveoli. And the plants have obvious functions of blocking, filtering and adsorbing dust, so that dust particles in the atmosphere can be effectively reduced in urban greening construction. This aspect of research has now progressed from individual plants to different plant communities for dust holding capacity. In order to measure PM near plant community more accurately in research10And PM2.5The spatial distribution and the change condition of the concentration need a detecting instrument with multi-position and real-time detection capability and a small probe volume, thereby being convenient to be arranged around the plant community.
However, most of the existing light scattering particle analyzers are handheld portable measuring instruments, which are inconvenient to arrange and cannot realize multi-position simultaneous detection, and only single-point measurement can be realized. And related academic research at home and abroad is mainly developed around improving the measurement precision of a single probe, and research aiming at solving the requirements of probe miniaturization and quasi-distributed measurement in the current engineering application is blank.
In summary, the objective disadvantage of the prior art is the lack of an instrument device for accurately measuring environmental indicators. Based on this, the environment detecting instrument device and system based on the optical fiber structure provided by the embodiment of the invention adopt the all-fiber design, have few optical discrete elements, high system reliability and small probe volume, are easy to lay in the environment and are more suitable for the current environment detection.
Is convenient for the pairThe present embodiment understands that, first, the environment PM based on the optical fiber structure disclosed in the embodiment of the present invention is described10And PM2.5The probe apparatus is described in detail.
The first embodiment is as follows:
referring to fig. 1, a PM based optical fiber structure10And PM2.5A probe instrument apparatus comprising: an optical signal generating unit 100, a detection array 200, and an optical frequency conversion unit 300;
the optical signal generating unit 100 is connected with the detection array 200, and is used for generating an optical signal and loading the optical signal to the detection array;
the detection array 200 is connected with the optical frequency conversion unit 300 and is used for emitting the optical signal, receiving a scattered light signal according to the particle scattering condition of the measurement area and sending the scattered light signal to the optical frequency conversion unit;
the optical frequency conversion unit 300 is configured to generate a frequency signal according to the scattered light signal, and obtain the distribution of different particle diameters and the environmental index in the atmosphere according to the frequency signal.
Further, a fiber coupler is included, the fiber coupler includes a first fiber coupler 400 and a second fiber coupler 500, and the probe array 200 includes a plurality of probes, the probes include a transmitting fiber and a receiving fiber.
Further, the first optical fiber coupler 400 is respectively connected to the optical signal generating unit 100 and the detection array 200, and is configured to split the optical signal generated by the optical signal generating unit and load the split optical signal to the detection array 200;
the second optical fiber coupler 500 is respectively connected to the detection array 200 and the optical frequency conversion unit 300, and is configured to combine the scattered light signals sent by the detection array 200, and send the combined scattered light signals to the optical frequency conversion unit 300.
Further, the optical signal generating unit 100 includes a laser 110, an intensity modulator 120, and a frequency modulated continuous wave FMCW signal source 130, and the optical frequency converting unit 300 includes a photodetector 310, a multiplier 320, a filter 330, and a fourier transform unit 340.
Further, a laser 110 connected to the intensity modulator 120 for generating a continuous light output with a constant light intensity to the intensity modulator;
an FMCW signal source 130 connected to the intensity modulator 120 for generating a first electrical signal and applying the first electrical signal to the intensity modulator;
and an intensity modulator 120 connected to the detection array 200 through a first fiber coupler 400 for modulating the continuous light into an FMCW optical signal according to the electrical signal.
Further, the photodetector 310 is connected to the second optical fiber coupler 500 and the multiplier 320, respectively, and is configured to convert the combined scattered light signal into a second electrical signal and send the second electrical signal to the multiplier;
a multiplier 320, respectively connected to the FMCW signal source 130 and the filter 330, for multiplying the second electrical signal by the first electrical signal generated by the FMCW signal source to obtain a third electrical signal;
and the fourier transform unit 340 is connected with the multiplier 320 through the filter 330, and is configured to perform fourier transform on the third electrical signal to obtain different frequency signals, so as to determine the particle diameter and the environmental index according to the pulse size and the number in the different frequency signals.
Furthermore, the number of the first optical fiber couplers is 4, and the number of the second optical fiber couplers is 1.
Further, the optical signal generates 4 sets of test light and 1 set of reference light after passing through the first fiber coupler, the test light is loaded on the emission fiber, and the reference light is loaded on the second fiber coupler to be combined with the scattered optical signal.
Further, the probe comprises a fiber optic ball lens.
The embodiment of the invention improves the traditional angle scattering method particle size measurement system. The optical fiber is used as a light guide medium, and the spherical end face of the optical fiber is used for replacing a traditional discrete lens, so that the probe is miniaturized. Frequency Modulated Continuous Wave (FMCW) technology is introduced into radar technology, and multiplexing of a plurality of probes is realized. The system can be used for PM of multiple positions in the environment10And PM2.5And simultaneously monitoring indexes on line. And the whole optical part of the system adoptsThe optical fiber design has the advantages of few optical discrete elements, high system reliability, small probe volume and easy laying in the environment. The design provides reference for further experimental study, and provides a feasible detection scheme for the plant community dust retention effect study.
Example two:
to achieve quasi-distributed measurements, the present embodiment provides for PM10And PM2.5A sensing array, as shown in fig. 2.
The system works as follows:
1. the laser outputs light continuously, and the light intensity is unchanged. The FMCW signal source loads the electrical signal to the intensity modulator, and the laser light passes through the intensity modulator to become the FMCW optical signal.
2. The modulated optical signal is split into light beams by a coupler (first optical fiber coupler) and enters each probe. In order to make the laser intensity entering each probe the same, the splitting ratio of C1 to C4 is 1:4, 1:3, 1:2, 1:1, respectively.
3. The light split off by the coupler enters each probe where the emitting fiber emits a very thin beam of parallel light defining a measurement area a at the waist of the beam (the volume is small enough to assume that only one particle passes at a time). While the focal point of the receiving fiber falls within region a. When the measurement zone is free of particles, no scattering phenomena occur and no light enters the receiving fiber. When particles pass through the measuring area, a scattering signal is generated, and light enters the receiving optical fiber.
4. The four receiving optical fibers of R1, R2, R3 and R4 enter the detector after being combined by the coupler (second optical fiber coupler). R5 is reference light, and the influence of the fluctuation of the laser light intensity on the detection precision is reduced.
5. The received light is converted into an electric signal by a photoelectric detector and multiplied by the electric signal generated by the original FMCW signal source. The returned optical signal has a different delay from the signal generated by the FMCW due to the different optical path difference. Thereby generating different frequencies.
6. The multiplied signals are subjected to fast fourier transform of the different frequency signals.
7. When particles pass through the measuring region in the leftmost probeAnd R1 receives a pulse signal. After the fast fourier transform, a pulse signal appears at the frequency of the response (the frequency can be accurately designed by the optical path plus the delay loop). The number of particles passing through the first probe can be known by calculating the number of signals at the frequency in unit time. The diameters of all particles can be obtained by the relationship between the pulse size and the particle diameter. Finally, the distribution of different particle diameters and PM in the atmosphere can be known through long-time statistics10And PM2.5And the like.
It should be noted that, in the prior art, the concentration statistical process belongs to related contents on an algorithm, and is mature, and this embodiment does not give much description. The innovation point of the embodiment is that the structure of the optical fiber is used, the distribution measurement of multiple points can be realized, a discrete lens in a commercial detector is not used, and the optical fiber spherical lens is used, so that the miniaturization and high reliability of the system are realized. The use of FMCW modulation is intended to distinguish between different probe signals.
The detection array is composed of four elements, and the laser emits light into the light intensity modulator. According to the frequency modulated continuous wave principle, a signal generator generates an FMCW signal whose frequency varies periodically. One path of signal is used for intensity modulation of the laser, and the other path of signal is used as a reference signal and input into a multiplier. The modulated laser light is split into light beams by couplers C1-C4 and enters different probes. When particles pass through the detection area of a certain probe, the corresponding receiving optical fiber collects scattered optical signals to a photoelectric detector and converts the scattered optical signals into electric signals.
When multiple probes pass by a particle simultaneously, signals cannot be distinguished in the time domain. However, the optical paths of the four probes are different, and different difference frequency signals are obtained after the signals of all paths are multiplied by the reference signals, so that the signals of different probes are distinguished. Assuming that the difference frequency obtained after Fourier transform is f1、f2、f3、f4Wherein f is1～f4The four probes are respectively used for detecting signals. During testing, when particles pass through a measuring area in the probe, pulses appear in corresponding frequency signals, the number of the pulses corresponds to the number of the particles, and the size of the pulses corresponds to the diameter of the particles. Through a long time systemThe PM of four-position atmosphere can be obtained by measuring the particle distribution and mass concentration2.5And PM10And (4) indexes.
The system is an intensity type optical fiber sensing system, so that the particle size measurement is inaccurate due to the power fluctuation of a laser. In order to reduce the influence of optical power fluctuation, the light received by R5 is taken as reference light intensity, and the corresponding frequency difference is f5. The signal is a continuous signal, the amplitude of which is proportional to the laser power. By f1Divided by f4f5Thereby eliminating power fluctuation effects.
The principle of the angular scattering measurement according to the present embodiment is explained as follows:
particles in the atmosphere having a diameter of less than 10 μm are generally ellipsoidal and can be approximated as isotropic spherical particles. According to the MIE scattering theory, when parallel light is incident on a spherical particle, the spatial distribution of the scattered light intensity is expressed as:
in the formula, theta is the included angle between scattered light and incident light, I0The distance r between the observation point and the particle is the incident light intensity and lambda is the laser wavelength. S1(theta) and S2(θ) is the amplitude distribution function parallel and perpendicular to the scattering cross section, respectively, and is expressed as:
wherein the coefficient anAnd bnIs a parameter related to the size of spherical particles
(a is the particle diameter) and refractive index m, expressed as follows:
in the formula (I), the compound is shown in the specification,
ξn、ξ’nis a function related to Bessel and Hankel of a half order, and can be directly calculated by a function carried by Matlab software. In the formula (2), the angular scattering function τnAnd pinThe expression is as follows:
wherein the content of the first and second substances,
the Legendre polynomial can be recurred from a low order to a high order, and the recurrence formula is as follows:
will initial value pi0＝0，π1The scattering angle function of each order can be obtained by substituting 1 into the above equation.
From the MIE scattering theory, it is known from the results of simulation of the scattering characteristics of fine particles having different diameters, i.e., a laser wavelength λ of 650nm and a refractive index m of 1.57 to 0.56i, by Matlab software, and from the results of simulation of the spatial distribution of the scattered light intensity when the particle diameter a is 0.1 μm, 0.5 μm, 2.5 μm, 5 μm, or 10 μm. When a/lambda < <1, the forward and backward scattering intensity is uniformly distributed, then Rayleigh scattering occurs; when the particle size increases to a size close to the wavelength, the total scattered light intensity increases and concentrates towards a small angle range, at which point MIE scattering occurs. In order to improve the detection signal-to-noise ratio, forward small angle reception is usually employed.
The angular scattering method is a method of measuring the diameter of particles by measuring the scattered light flux within a certain angular range. Fig. 3 shows the relationship between the particle size and the luminous flux in the range of 5 ° to 30 ° scattering angle θ.
As can be seen from fig. 3, there is a unique correspondence between particle diameter and luminous flux within this angular range. By measuring light fluxThe size of the amount determines the diameter of the particle. The particle distribution and PM of different sizes of the whole air can be obtained by long-time measurement10And PM2.5And (4) indexes.
The basic principle of measurement of frequency modulated continuous waves according to the present embodiment is explained as follows:
frequency Modulated Continuous Wave (FMCW) technology is a technology used in high precision radar ranging. The basic principle of the FMCW radar is that the transmitted wave is a high-frequency continuous wave, the frequency changes according to a sawtooth wave rule with time, the change rule of the echo frequency received by the radar is the same as the change rule of the transmitted frequency, and only a time difference exists, as shown in fig. 4. In the figure ω0Is the central angular frequency, Δ ω is the sweep range of the angular frequency, TmIs the modulation period. The reference signal instantaneous angular frequency can be expressed as:
wherein, 0<t<Tm，
Indicating the rate of change of frequency.
Integrating the frequency with respect to time to obtain the phase of the signal, thereby obtaining a reference signal function S1(t)：
Also, a reflected signal S can be obtained2(t)
Mixing the reference signal and the reflected signal, and filtering the mixed signal by a low-pass filter to obtain a difference frequency signal:
in the formula, tau is the delay of the reference signal and the reflected signal. The angular frequency of the difference signal can be expressed as:
in the formula, c1To detect the signal propagation velocity, L reflects the location where the reflection event occurred. From the above equation, L and the difference frequency signal have a unique correspondence relationship.
The structure of the probe according to the present embodiment is described as follows:
when parallel light irradiates the particles, the forward small-angle received scattered light flux has a unique corresponding relation with the particle size, and the size of the particle diameter can be known by detecting the size of the light flux under a small angle. In existing research and products, most of the existing research and products are handheld, the particle concentration of one position can be measured at one time, and a probe usually adopts a discrete lens group to collimate and receive laser.
In order to realize the miniaturization of the probe, a fiber spherical end face is used for replacing a discrete lens group, and the newly designed probe structure is shown in figure 5.
The end faces of the transmitting and receiving fibers are spherical lenses. Compared with the flat-end optical fiber, the spherical end surface has the light-gathering characteristic, and an ideal focal length can be obtained by controlling the parameters of the ellipsoid. At present, the rattan-bin LZM-100 welding machine can realize the manufacture of a spherical end face, and parameters can be controlled by a program.
Example three:
environment PM based on optical fiber structure10And PM2.5Probe instrument system comprising an environmental PM based on an optical fiber structure as described above10And PM2.5The detection instrument device also comprises an instrument handle.
The embodiment of the invention provides an environment PM based on an optical fiber structure10And PM2.5The detecting instrument system has the same technical characteristics as the environment detecting instrument device based on the optical fiber structure provided by the above embodiment, so thatThe same technical problem can be solved, and the same technical effect can be achieved.
The embodiment of the invention provides an environment PM based on an optical fiber structure10And PM2.5The computer program product of the probe apparatus and the system includes a computer readable storage medium storing a program code, where instructions included in the program code may be used to execute the method described in the foregoing method embodiment, and specific implementation may refer to the method embodiment, which is not described herein again.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the system and the apparatus described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In addition, in the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (5)
1. PM based on optical fiber structure10And PM2.5A probing apparatus, comprising: the device comprises an optical signal generating unit, a detection array and an optical frequency conversion unit;
the optical signal generating unit is connected with the detection array and used for generating an optical signal and loading the optical signal to the detection array;
the detection array is connected with the optical frequency conversion unit and used for emitting the optical signals, receiving scattered light signals according to the particle scattering condition of the measurement area and sending the scattered light signals to the optical frequency conversion unit;
the optical frequency conversion unit is used for generating frequency signals according to the scattered light signals and acquiring the distribution of different particle diameters and environmental indexes in the atmosphere according to the frequency signals;
the PM based on the optical fiber structure10And PM2.5The detecting instrument device also comprises an optical fiber coupler, andthe fiber coupler comprises a first fiber coupler and a second fiber coupler, the detection array comprises a plurality of probes, and the probes comprise transmitting fibers and receiving fibers;
the PM based on the optical fiber structure10And PM2.5The probe apparatus further comprises:
the first optical fiber coupler is respectively connected with the optical signal generating unit and the detection array, and is used for splitting the optical signal generated by the optical signal generating unit to generate test light and reference light, loading the split test light to the emission optical fiber of the detection array and loading the reference light to the second optical fiber coupler;
the second optical fiber coupler is respectively connected with the detection array and the optical frequency conversion unit, and is used for combining the scattered light signals sent by the detection array and sending the combined scattered light signals to the optical frequency conversion unit;
the optical signal generating unit comprises a laser, an intensity modulator and a frequency modulation continuous wave FMCW signal source, and the optical frequency conversion unit comprises a photoelectric detector, a multiplier, a filter and a Fourier transform unit;
the laser is connected with the intensity modulator and used for generating continuous light with unchanged light intensity and outputting the continuous light to the intensity modulator;
the FMCW signal source is connected with the intensity modulator and used for generating a first electric signal and loading the first electric signal to the intensity modulator;
the intensity modulator is connected with the detection array through the first optical fiber coupler and is used for modulating the continuous light into FMCW optical signals according to the electric signals;
the photoelectric detector is respectively connected with the second optical fiber coupler and the multiplier, and is used for converting the combined scattered light signal into a second electric signal and sending the second electric signal to the multiplier;
the multiplier is respectively connected with the FMCW signal source and the filter and is used for multiplying the second electric signal and the first electric signal generated by the FMCW signal source to obtain a third electric signal;
the Fourier transform unit is connected with the multiplier through the filter and used for carrying out Fourier transform on the third electric signal to obtain different frequency signals so as to determine the particle diameter and the environmental index according to the pulse size and the number in the different frequency signals.
2. The fiber optic structure-based PM of claim 110And PM2.5The detection instrument device is characterized in that the number of the first optical fiber couplers is 4, and the number of the second optical fiber couplers is 1.
3. The fiber optic structure based PM of claim 210And PM2.5The detecting instrument device is characterized in that 4 groups of test light and 1 group of reference light are generated after the optical signals pass through the first optical fiber coupler, the test light is loaded on the emission optical fiber, and the reference light is loaded on the second optical fiber coupler to be combined with the scattered optical signals.
4. The fiber optic structure-based PM of claim 110And PM2.5A probing apparatus device wherein said probe comprises a fiber optic ball lens.
5. PM based on optical fiber structure10And PM2.5Probe apparatus system, comprising an environmental PM based on a fiber optic structure according to any of claims 1 to 410And PM2.5The detection instrument device also comprises an instrument handle.
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