CN102818756B - Based on assay method and the device of the PM2.5 particle of laser energy trapping method - Google Patents

Abstract

The invention discloses a measuring device for measuring particle concentration in gas, which is particularly suitable for measuring PM2.5 particle concentration. In the present invention, the parallel laser beam emitted by the laser is scattered by the light scatterer and then incident to a detection cavity through the light converging device, forming a spatial speckle field in the detection cavity, or passing the parallel laser beam through a flat After the convex lens converges and irradiates an orthogonal grating, the generated 0-order and 1-order diffracted light converges to the inner area of the detection cavity through the first objective lens to form a spatial optical lattice. The spatial speckle field or spatial optical crystal Each grid contains energy traps, and the size of the energy traps is adjusted so that the size of the energy traps is in the peak region of the particle size distribution of the required bound particle range, and the concentration of particles in the selected particle size range in the gas to be measured is measured by a calibration method. The invention has simple structure and low cost, and can realize the measurement of particles with different sizes.

Description

Method and device for measuring PM2.5 particles based on laser energy trap method

technical field

The invention belongs to the technical field of ambient air collection and monitoring, and in particular relates to a method and a device for measuring PM2.5 particles. The invention can provide PM2.5 analysis samples for various analytical instrument fields, and can realize online monitoring of PM2.5 at the same time.

Background technique

Atmospheric environment has a vital impact on people's health, and inhalable particulate matter in the atmosphere has always been the focus of atmospheric environment monitoring. PM2.5 particles refer to particulate matter with a diameter less than or equal to 2.5 microns in the atmosphere, also known as particulate matter that can enter the lungs. Due to its small particle size, it is very easy to carry a large amount of harmful substances such as viruses and bacteria, and it is not easy to precipitate. It stays in the air for a long time and has a long transportation distance. After being inhaled into the human body, it will directly enter the bronchi and interfere with the gas exchange of the lungs. , causing diseases including asthma, bronchitis and cardiovascular disease.

PM2.5 measurement refers to the measurement of the concentration of PM2.5 particles in the atmosphere. At present, the existing PM2.5 measurement methods mainly include gravimetric method, β-ray method and micro-oscillating balance method. The gravimetric method is to trap PM2.5 particles directly on the filter membrane, and then weigh them with a balance. The gravimetric method is the most direct and reliable method, and is the benchmark for verifying the accuracy of other methods. However, manual weighing is required, and the procedure is cumbersome and time-consuming. The β-ray method is to collect PM2.5 particles on filter paper, and then irradiate a beam of β-rays. When the β-rays pass through the filter paper and particulate matter, they are attenuated due to scattering. The degree of attenuation is proportional to the weight of PM2.5. According to the ray attenuation The weight of PM2.5 particles can be calculated to calculate the concentration. This method assumes that the sampling filter strips of the instrument are uniform and the physical properties of the collected PM2.5 particles are uniform, and their intensity attenuation rates for β rays are the same. But in reality, this assumption is often not true, so the data is generally considered to be biased, and the method has a high failure rate in humid and high temperature areas. The micro-oscillating balance method uses a hollow glass tube with a thick end and a thin end, the thick end is fixed, and the thin end is equipped with a filter element. Atmospheric samples enter from the thick end and exit from the fine end, PM2.5 is trapped on the filter element. Under the action of the electric field, the thin head oscillates at a frequency that is inversely proportional to the square root of the weight of the thin head. Therefore, according to the change of the oscillation frequency, the weight of the collected PM2.5 can be calculated, thereby calculating the concentration. When using this method, the volatile and semi-volatile substances of the sample will be lost, and a membrane dynamic measurement system (FDMS) needs to be installed for calibration, and the FDMS water permeable membrane needs to be replaced. The material cost is expensive, and it takes at least half a day for professional technicians to operate .

These methods all need to pass the air sample to be measured through the PM2.5 sampling cutter first, cut the particles with a diameter larger than 2.5 μm, so that the particles with a diameter smaller than 2.5 μm can pass through, and then measure the gas.

Contents of the invention

(1) Technical problems to be solved

The technical problem to be solved by the present invention proposes a method and device for sampling and monitoring PM2.5 particles based on the laser energy trap method, to solve the problem that the existing PM2.5 particle sampling and monitoring method and device must first pass the gas through PM2 .5 Sampling cutter, and the equipment has complex structure, high cost, need to replace filter paper, and cumbersome operation.

(2) Technical solution

In order to solve the above-mentioned technical problems, the present invention proposes a measuring device for measuring the concentration of particles in gas, which is used to measure the concentration of particles in a predetermined particle size range in the gas to be measured. The device includes a laser, a light scatterer, a light converging device and detection cavity, and,

The laser is used to emit a parallel laser beam, the parallel laser beam is scattered by the light scatterer and then enters the detection cavity through the light converger, forming a spatial speckle field in the detection cavity, The spatial speckle field contains energy traps,

The detection cavity is used to accommodate the gas to be measured, and is located on the image plane of the light concentrator. Part of the particles in the gas to be measured are bound by the energy trap, and the particle size distribution of the bound particles is the same as The size of the energy trap in the direction perpendicular to the propagation direction of the laser beam is related, and the concentration of particles in a predetermined particle size range in the gas to be measured can be determined according to the number and size distribution of particles of the trapped size.

The present invention also proposes a multi-channel measuring device for measuring the concentration of particles in the gas, which is used to measure the concentration of particles in a plurality of predetermined particle size intervals in the gas to be measured, including a plurality of sub-devices, each sub-device includes a laser, a light scatterer , a light concentrator, a plurality of sub-devices share a detection cavity, and,

The laser of each sub-device is used to emit a parallel laser beam, which is scattered by the light scatterer of the sub-device and then enters the detection cavity through the light concentrator of the sub-device. A plurality of spatial speckle fields are formed in the cavity, and the spatial speckle fields contain energy traps,

The detection cavity is used to accommodate the gas to be tested, and its center in the horizontal direction is located on the image plane of the optical concentrator of each sub-device, and the particle size in the gas to be tested is determined by the size of the plurality of energy traps Particles in the peak region of the particle size distribution of the trapped particles are trapped by the energy traps of each spatial speckle field, the number and particle size distribution of the trapped particles of multiple sizes can be measured to determine the analyte gas The concentration of particles in a plurality of predetermined particle size intervals,

Wherein, the laser wavelength of each sub-device, the distance between the light concentrator and the image plane, and the aperture size of the light concentrator can be adjusted, so that the particle size distribution of the required bound particles is determined by the size of the energy trap Determines the peak region of the size distribution of particles that can be bound.

The present invention also proposes a measuring device for measuring the concentration of particles in gas, which is used to measure the concentration of particles in a predetermined particle size range in the gas to be measured, which is characterized in that it includes a laser, a detection cavity, a plano-convex lens, an orthogonal grating and first objective lens,

The laser is used to emit a parallel laser beam, the laser beam is converged by the plano-convex lens and irradiated on the orthogonal grating, and the generated 0th order and 1st order diffracted light are converged to the said first objective lens. The inner area of the detection cavity forms a spatial optical lattice, the spatial optical lattice contains energy traps, the energy traps can bind part of the particles, the particle size distribution of the bound particles is related to the size of the energy traps, according to The number and particle size distribution of the particles of the bound size can determine the concentration of particles in the predetermined particle size range in the gas to be measured,

The detection cavity is used to accommodate the gas to be measured, and its horizontal center is located on the image plane of the first objective lens. The laser wavelength, the distance from the first-order diffracted light to the x-axis, and the waist The parameters of the radius, the first-order diffracted light axis and the x-axis inclination angle can be adjusted so that the particle size distribution of the required bound particles is in the peak area of the particle size distribution of the bound particles determined by the size of the energy trap, where the x-axis direction is The propagation direction of the laser beams of the plurality of sub-devices.

The present invention also proposes a multi-channel measurement device for measuring particle concentration in gas, which is used to measure the concentration of particles in a plurality of predetermined particle size intervals in the gas to be measured, including a plurality of sub-devices, each sub-device includes a laser, a plano-convex lens, Orthogonal grating and first objective lens, multiple sub-assemblies share one detection cavity, and

The laser of each sub-device is used to emit a parallel laser beam. The laser beam is converged by the plano-convex lens of the sub-device and irradiated on the orthogonal grating of the sub-device. The first objective lens of the sub-device converges to the inner area of the detection cavity to form a plurality of spatial optical lattices, the spatial optical lattices contain energy traps, the energy traps can bind part of the particles, and the particles of the bound particles The size distribution is related to the size of the energy trap, and the concentration of particles in the predetermined particle size range in the gas to be measured can be determined according to the number and particle size distribution of particles of the trapped size,

The detection cavity is used to accommodate the gas to be measured, and is located on the image plane of the first objective lens of each sub-device, the laser wavelength of each sub-device, the distance from the first-order diffracted light to the x-axis, a The light waist radius of the first-order diffracted light and the parameters of the first-order diffracted light axis and the x-axis inclination angle can be adjusted so that the particle size distribution of the required bound particles is in the peak area of the particle size distribution of the bound particles determined by the size of the energy trap , wherein the x-axis direction is the propagation direction of the laser beams of the plurality of sub-devices.

The present invention also proposes a multi-channel measuring device for measuring the concentration of particles in gas, which is used to measure the concentration of particles in a plurality of predetermined particle size intervals in the gas to be measured, which is characterized in that it includes at least one first sub-device and at least one The second sub-device, wherein the first sub-device includes a laser, a light scatterer, and a light converging device, and the second sub-device includes a laser, a plano-convex lens, an orthogonal grating, and a first objective lens, and the first sub-device and the second sub-device The devices share a single detection chamber, and,

The detection cavity is used to accommodate the gas to be measured, and its center in the horizontal direction is located on the image plane of the light converging device of the first sub-device, and is located on the image plane of the first objective lens of the second sub-device,

The laser of the first sub-device is used to emit a parallel laser beam, and the parallel laser beam is scattered by the light scatterer of the first sub-device and then enters the detection cavity through the light concentrator of the first sub-device , forming a spatial speckle field in the detection chamber, the spatial speckle field contains energy traps, some particles in the gas to be measured are trapped by the energy traps, and the particle size distribution of the trapped particles is the same as that of the The size of the energy trap in the direction perpendicular to the propagation direction of the laser beam is related, and the concentration of particles in the predetermined particle size range in the gas to be measured can be determined according to the number and particle size distribution of the particles of the trapped size,

The laser wavelength of the first sub-device, the distance between the light converging device and the image plane of the first sub-device and the aperture size of the light converging device can be adjusted, so that the size of the bound particles is a plurality of the Predetermined particle size range,

The laser of the second sub-device is used to emit a parallel laser beam, and after the laser beam is converged by the plano-convex lens of the second sub-device, it is irradiated on the orthogonal grating of the second sub-device, and the generated 0-order and 1st-order diffracted light converge to the inner area of the detection cavity through the first objective lens of the second sub-device to form a spatial optical lattice, which contains energy traps that can bind part of the particles , the particle size distribution of the bound particles is related to the size of the energy trap, and the concentration of particles in the predetermined particle size range in the gas to be measured can be determined according to the number and particle size distribution of the bound particles ,

The laser wavelength of the second sub-device, the distance from the first-order diffracted light to the x-axis at the optical lattice, the waist radius of the first-order diffracted light, and the inclination angle parameters of the first-order diffracted light axis and the x-axis can be adjusted so that the required The particle size distribution of the bound particles is in the peak area of the particle size distribution of the bound particles determined by the size of the energy trap, wherein the x-axis direction is the propagation direction of the laser beams of the plurality of sub-devices.

The present invention also proposes a method for measuring the concentration of particles in the gas, which is used to measure the concentration of particles in a predetermined particle size range in the gas to be measured, including the following steps:

emitting a parallel laser beam so that the parallel laser beam is scattered by a light scatterer and then converged and incident on a detection cavity, forming a spatial speckle field in the detection cavity, the spatial speckle field contains energy traps, Part of the particles in the gas to be measured are bound by the spatial speckle field,

The number and particle size distribution of the bound particles are measured, thereby determining the concentration of particles of the predetermined particle size distribution in the gas to be measured.

The present invention also proposes a method for measuring the concentration of particles in the gas, which is used to measure the concentration of particles in a predetermined particle size range in the gas to be measured, which is characterized in that it includes the following steps:

A parallel laser beam is emitted, and the laser beam is converged and irradiated on an orthogonal grating to generate 0-order and 1-order diffracted light, so that the diffracted light is converged to the inner area of a detection cavity to form a spatial optical lattice, The space light lattice contains energy traps, which can bind some particles,

The number and size distribution of the bound particles are measured to determine the concentration of particles of the predetermined size distribution in the gas to be measured.

(3) Beneficial effects

The invention can directly sample and measure the PM2.5 particles without using a PM2.5 sampling cutter, and the method is simple and efficient without changing the filter paper. Specifically, the present invention utilizes many optical energy traps formed by spatial speckle fields or spatial optical lattices to bind PM2.5 particles. Compared with existing PM2.5 measuring devices, its advantages are as follows: (1) the device of the present invention The detection optical path structure is simple and easy to realize; (2) each component of the device of the present invention is cheap, so the cost is relatively low; (3) the present invention can realize the measurement of particles of different sizes through the parameters of each component in the optical path system; (4) the present invention does not need to replace the filter membrane, reducing the amount of manual operation; (5) the PM2.5 measuring device of the present invention is small in size, light in weight and easy to carry; (6) the device and method of the present invention can realize multi-channel classification real-time monitoring.

Description of drawings

Figure 1 is an effect diagram of the laser speckle field;

Figure 2 is a schematic diagram of the spatial intensity distribution of the optical lattice observed at different angles;

Fig. 3 is an image of bound particles based on spatial optical lattice energy trap;

4 is a schematic structural view of a device for measuring PM2.5 particles based on a laser speckle field according to Embodiment 1 of the present invention;

5 is a schematic structural diagram of a multi-channel hierarchical real-time measurement device for measuring PM2.5 particles based on a laser speckle field energy trap according to Embodiment 2 of the present invention;

6 is a schematic structural view of the PM2.5 particle measuring device based on the spatial optical lattice energy trap produced by the orthogonal grating according to Embodiment 3 of the present invention;

7 is a schematic structural diagram of a multi-channel hierarchical real-time measurement device for measuring PM2.5 particles based on a spatial optical lattice energy trap according to Embodiment 4 of the present invention;

Fig. 8 is a schematic structural diagram of a multi-channel hierarchical real-time measurement device for measuring PM2.5 particles based on the combination of the spatial speckle field and the spatial optical lattice energy trap according to Example 5 of the present invention.

detailed description

The invention proposes an innovative PM2.5 measuring method and device. The principle of the present invention is that by adjusting the energy distribution of the light field generated by the continuous laser beam, a three-dimensional grid with multiple light field energy traps is formed, just like a large number of light bottles, which can bind a large number of micron-scale particles in the sample gas. particles. By adjusting the size of the energy trap to change the particle size range of the required bound particles, the sampling of PM2.5 particles in the sample gas is realized. At the same time, the number and particle size distribution of the bound particles can be observed and recorded by the CCD, and the measured value of the particle size distribution in the sample gas can be obtained. The relationship between bound quantity and mass is determined by calibration in advance, so as to obtain the concentration of PM2.5 in the sample gas.

In order to realize the three-dimensional light field distribution with multiple light field energy traps, the invention adopts the laser speckle field method and the orthogonal grid grating method. The principle of these two methods and the basic structure of the device are firstly introduced below:

1. Laser speckle field method

A continuous laser beam emitted by a laser (the wavelength of the emitted laser is λ, and the beam width is D) irradiates the ground glass diffuser inches, 1500 sands, divergence angle 6°) and after being converged by the light concentrator (focal length f), a stable spatial speckle field is formed on the image plane. The spatial speckle field contains multiple energy traps, like many tiny light bottles, which can selectively bind particles of a certain size in the light bottle, while particles of other sizes will flow out, thus realizing the measurement of PM2.5 particles ( Vladlen G. Shvedov, Andrei V. Rode, Yana V. Izdebskaya, Anton S. Desyatnikov, Wieslaw Krolikowski and Yuri S. Kivshar, "Selective trapping of multiple particles by volumespecklefield", OPTICS EXPRESS, Vol. 18, 3137, 2010).

When highly coherent light (such as laser) is used to irradiate a diffuse reflective surface or a non-uniform transparent medium, an imaging lens is used to image the illuminated diffuse object (including diffuse reflection and transmission), and a randomly distributed scatter pattern will be formed in the space behind the lens. Speckle field, this speckle field is called subjective speckle. Although the speckle structure is random, for a certain non-uniform transparent medium and a certain illumination laser light source, the corresponding speckle field is also determined. The sizes of the speckle particles perpendicular to the direction of light propagation and parallel to the direction of light propagation on the image plane are:

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{<span\; class="notranslate">\; \&perp;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2.44</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; Za</span>}}{\mathrm{<span\; class="notranslate">\; Da</span>}}<span\; class="notranslate">\; )</span>$

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 16</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; Za</span>}}{\mathrm{<span\; class="notranslate">\; Da</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

Wherein λ is the laser wavelength, Za is the distance from the lens to the image plane, and Da is the lens aperture size (J.W.Goodman, SpecklePhenomenainOptics (BenRobertsandCo., CO, 2007). The distance between the laser wavelength, the lens and the image plane and The aperture size of the lens can be adjusted, so that the size of the bound particles is within a predetermined particle size range.

Figure 1 is an effect diagram of the laser speckle field in space. As shown in Figure 1, the bar-shaped objects represent speckle particles, and the spherical objects represent particles trapped in energy traps. The laser speckle field in this space is recorded in real time through the CCD, and the recorded information is input into the computer. The light scattered by the bound particles is imaged on the CCD target surface, and the image received by the CCD is processed to obtain the number and particle size distribution of the bound particles, so as to obtain the concentration of particles with the predetermined particle size distribution.

The energy trap formed based on the laser speckle field is selective to the particle size of the trapped tiny particles, and the principle of the bound tiny particles is as follows:

The three-dimensional speckle particles are separated by many black areas, and these black areas are many light energy traps. Optical energy traps are like tiny light bottles, which can bind some particles in the gas to be measured. The particle size peak range of the bound particles is related to the size of the energy trap in the vertical direction of the laser beam propagation direction. By adjusting the size of the energy trap in the vertical direction to the propagation direction of the laser beam, the particle size distribution peak interval of the trapped particles can be adjusted. Since the laser wavelength λ, the distance Za from the image plane to the lens and the aperture size Da of the lens are all adjustable, by adjusting the values of λ, Za and Da, the particle size distribution peak interval of the bound particles can be controlled. Since the particle size distribution of the bound particles is related to the concentration of particles in the predetermined particle size range in the gas to be measured, the concentration of particles in the predetermined particle size range can be measured by calibrating the measuring device. When processing the image received by the CCD, the particle data with a particle size larger than 2.5 μm can be ignored, and only particles with a particle size smaller than 2.5 μm can be processed, so this device does not need to be used for PM2,5 monitoring. Add PM2.5 cutter before the system.

2. Orthogonal grid grating method

The parallel light beam generated by the laser is converged on the orthogonal diffraction grating through the plano-convex lens, and the 0-order and 1-order diffracted light generated pass through the beam splitting prism, and then converged to a certain area through an imaging objective lens to form an optical lattice and generate a large number of energy traps , particles of a certain size can be bound, thereby realizing the sampling of PM2.5 particles (seeing VladlenG.Shvedov, CyrilHnatovsky, NataliaShostka, AndreiV.Rode and WieslawKrolikowski, "Optical manipulation of particle ensembles in air", OPTICSLETERS, Vol.37, 1934, 2012).

Fig. 2 is a schematic diagram of the spatial intensity distribution of the optical lattice observed at different angles. As shown in Figure 2, the white arrow is the laser propagation direction, where: (a) in Figure 2 is the three-dimensionally divided particles of light intensity observed along the beam propagation direction, and the layout is convenient; (b) is facing the beam The three-dimensional distribution diagram of light intensity observed in the propagation direction; (c) is the three-dimensional distribution diagram of light intensity observed in the side direction. It can be seen from Figure 2 that there are many dark areas distributed in the space of the optical lattice, forming energy traps, which can bind some particles in the gas to be measured, and the size of the bound particles is related to the size of the energy traps. By adjusting the size of the energy trap in the vertical direction to the propagation direction of the laser beam, the particle size distribution range of the bound particles can be adjusted. In Fig. 2, the bright areas represent areas with high light intensity, and the dark areas between the bright areas are energy traps with low light intensity. The light from another white light source is reflected on the dichroic prism, and then enters the first imaging objective lens to illuminate the confinement area and observe the particles. A filter with the same wavelength as the laser needs to be placed after the second imaging objective lens, which can reduce the light intensity of the laser, and the white light irradiated to the optical lattice area can pass through the filter and be received by the CCD. By simply rotating and translating the grating, the corresponding effect of rotating and translating the particles can be achieved. The image received by the CCD is processed to obtain the number and particle size distribution of the bound particles, so that the concentration of the bound particles can be calculated. By adjusting the wavelength of the light, the distance from the first-order diffracted light to the x-axis, the radius of the first-order diffracted light waist, and the parameters of the inclination angle between the first-order diffracted light axis and the x-axis, the particle size distribution peak interval of the bound particles can be controlled, where the x direction is The propagation direction of the laser beams of the plurality of sub-devices. Since the particle size distribution of the bound particles is related to the concentration of particles in the predetermined particle size range in the gas to be measured, the concentration of particles in the predetermined particle size range can be measured by calibrating the measuring device.

The optical energy trap formed based on the spatial optical lattice is selective to the particle size of the trapped tiny particles, and the principle of the bound tiny particles is as follows:

The space light lattice is separated by many black regions, and these black regions are just many traps of light energy. Optical energy traps are like tiny light bottles, which can bind some particles in the gas to be measured. The peak range of the particle size of the bound particles is related to the size of the energy trap in the vertical direction of the laser beam propagation direction. By adjusting the size of the energy trap, the particle size distribution peak interval of the trapped particles can be adjusted. Since the size of the optical energy trap is related to the laser wavelength, the distance from the first-order diffracted light to the x-axis, the radius of the first-order diffracted light waist, and the axis of the first-order diffracted light to the x-axis inclination parameter, by adjusting the laser wavelength, the first-order diffracted light to x The axis distance, the first-order diffracted light waist radius, and the first-order diffracted light axis and x-axis inclination parameters can control the particle size distribution peak interval of the bound particles, where the x-axis direction is the laser propagation direction. Since the particle size distribution of the bound particles is related to the concentration of particles of a predetermined size in the gas to be measured, the concentration of particles of a predetermined size can be measured by calibrating the measuring device. When processing the image received by the CCD, the particle data with a particle size larger than 2.5 μm can be ignored, and only particles with a particle size smaller than 2.5 μm can be processed, so this device does not need to be used for PM2.5 monitoring. Add PM2.5 cutter before the system.

Figure 3 is an image of particles bound based on spatial optical lattice energy traps. (1), (2) and (3) in Figure 3 are orthogonal gratings rotated counterclockwise, and the spatial distribution of the optical lattices generated is also rotated accordingly, and the bound particles (black dots) are also rotated accordingly; ( 4), (5) and (6) are the grating translation, the resulting spatial distribution of the optical lattice also translates correspondingly, and the bound particles (black dots) also translate accordingly. It can be seen from this that the orthogonal The optical lattice generated by the grating has a binding effect on particles of certain sizes, which can be used to realize the sampling and monitoring of PM2.5.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

Embodiment 1: PM2.5 particle measuring device and its measuring method based on laser speckle field energy trap

Fig. 4 is a schematic structural diagram of a device for measuring PM2.5 particles based on a laser speckle field according to Embodiment 1 of the present invention. As shown in Figure 4, the device of the present invention comprises a laser 1, a light scatterer 2, a light converging device 3, a detection cavity 4, an imaging lens 5 and a CCD 6, wherein the laser 1 is used to emit a parallel laser beam, and the propagation of the laser beam The direction is the x direction in the figure, and in this embodiment, the x direction is the horizontal direction; the flow direction of the gas to be measured is the y direction in the figure, and in this embodiment, the y direction is the vertical direction, perpendicular to the x direction. The light beam emitted by the laser 1 passes through a light scatterer 2 and then enters the detection cavity 4 through a light converging device 3 . The light scatterer 2 scatters the laser light emitted by the laser, and the scattered laser light enters the detection cavity 4 through the light converging device 3. The detection cavity 4 is used to accommodate the gas to be measured, and its horizontal center is located at the light converging device 3 On the image plane, the so-called image plane refers to the imaging plane of the laser light scattered on the light converging device and the light scattering device. After the laser light enters the detection cavity 4 , the particles in the gas to be measured that meet the aforementioned size conditions are bound, and the light scattered by the surface of the bound particles passes through the imaging lens 5 and is received by the CCD 6 .

In the embodiment shown in FIG. 4 , the imaging lens 5 and the CCD 6 are placed in such a way that their axes are perpendicular to the xy plane formed by the x direction and the y direction.

In the embodiment shown in FIG. 4 , the laser 1 is a semiconductor laser with a wavelength λ of 532 nm and a beam width D of 2.6 mm, which emits a continuous laser beam. The light diffuser 2 is a ground glass diffuser whose scattering angle is 6°. The light converging device 3 is composed of a lens with a focal length f of 25 mm. After the laser light is converged, a stable spatial speckle field is formed in the image plane region.

In the embodiment shown in FIG. 4 , the distance Zo between the diffuser 2 and the lens 3 is 140 mm, the distance Za to the image plane is 30.4 mm, the image width Db is 570 μm, and the lens aperture Da is 23 mm. The size ε _|| of the speckle along the direction parallel to the laser propagation direction and the size ε _⊥ along the direction perpendicular to the laser propagation direction are respectively:

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{<span\; class="notranslate">\; \&perp;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2.44</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; Za</span>}}{\mathrm{<span\; class="notranslate">\; Da</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1.7</span>}\mathrm{<span\; class="notranslate">\; \&mu;m</span>}$

${\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{<span\; class="notranslate">\; |</span><span\; class="notranslate">\; |</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 16</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}{<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; Za</span>}}{\mathrm{<span\; class="notranslate">\; Da</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 14.9</span>}\mathrm{<span\; class="notranslate">\; \&mu;m</span>}$

Thus, by adjusting the laser wavelength, the distance between the light concentrator 3 and the image plane, and the aperture size of the light concentrator 3, the particle size distribution and the presence of ε _⊥ of the bound particles can be determined , which is, for example, an approximate normal distribution with a peak near ε _⊥ as the center.

Since the particle size distribution of the bound particles is also related to the concentration of particles in the predetermined particle size range in the gas to be measured, the concentration of particles in the predetermined particle size range can be measured by calibrating the measuring device. In the embodiment shown in Fig. 4, when using the device of the present invention, the gas to be tested is sent into the detection cavity 4, and the detection cavity 4 includes a gas inlet and a gas outlet, which are respectively used for feeding and discharging gas. The outer casing of the detection chamber can be made of glass with good light transmission, and coated with an anti-reflection film with the same wavelength as the laser, so as to facilitate the transmission of the laser beam and the CCD to receive the light scattered by the particles.

The image received by the CCD is input into the computer, and the size and quantity of the bound particles are identified through a specific control program, so that the number of particles of different sizes can be counted, and the particle size distribution of the particles can be obtained. The mass corresponding to individual particles of different sizes is known, and the mass of particles of different particle sizes can be obtained by multiplying the mass by the corresponding quantity. Since not all sizes of particles are bound, the bound particles are close to the size of the optical energy trap and have an approximately normal distribution. Therefore, it is necessary to obtain the particle size of the bound particles by passing in particles of different sizes with a certain mass The diameter distribution and the weight of particles of each size are compared with the weight of each size of the gas passed in, and the percentage of the bound particles of each size in the size of the gas passed is obtained, so as to realize the calibration of the device. Using the measuring device of the present invention, by adjusting the laser wavelength, the distance from the light concentrator to the image plane, and the aperture size of the light concentrator, a suitable light energy trap is obtained, so that the normal distribution peak value of the size of the bound particles is close to 2.5 μm , and calculate the number of particles of each size smaller than or equal to 2.5 μm in the bound particles, multiply the weight of a single particle of the corresponding size and divide it by the percentage of the size captured, the weight of each size in the gas can be obtained. Add the weights of particles of all sizes to get the total weight of PM2.5 in the gas, and divide it by the volume of the gas to get the PM2.5 concentration.

In the embodiment shown in FIG. 4 , after sampling for a period of time, stop feeding the gas and turn off the laser, so that the binding force to the bound particles disappears. At this time, no particles are bound, and the particles can be captured again. Such recycling, do not need to replace the filter paper.

Example 2: Measuring device and method for real-time measurement of PM2.5 particles based on laser speckle field energy trap multi-channel classification

Fig. 5 is a schematic structural diagram of a measurement device for measuring tiny particles in real-time by multi-channel classification based on laser speckle field energy traps according to Embodiment 2 of the present invention. As shown in Figure 5, the two devices shown in Figure 4 are integrated together as sub-devices, so that their image planes are on the same plane, the energy trap size of each sub-device is different, and the speckle field at the airflow inlet The size of the generated energy trap is the largest, and the size of the energy trap decreases successively from the airflow inlet to the airflow outlet. However, the present invention is not limited to the case of two sub-devices as shown in FIG. 5 , and this embodiment can also be extended to a multi-pass device with more than two sub-devices as required.

As shown in Fig. 5, the detection cavity 4, the imaging lens 5 and the CCD 6 are shared, and the laser 1, the ground glass scattering sheet 2 and the light concentrator 3 need to be used separately for each device.

In the embodiment shown in FIG. 5 , the imaging lens 5 and the CCD 6 are placed in such a way that their axes are perpendicular to the xy plane.

In the embodiment shown in Fig. 5, the laser beams emitted by the lasers 1, 1' of each sub-device pass through the light scattering sheets 2, 2' and then reach the detection cavity 4 through the light converging devices 3, 3'. Since the wavelength λ of each sub-device is different, Da (aperture size of the light concentrator) and Za (distance from the light concentrator to the image plane) are different, the resulting energy trap size is also different, which can bind particles in different size ranges. Different sub-devices are adjusted so that the image planes of several sub-devices are on the same plane, that is, the common imaging lens 5 and CCD 6 can be used for image acquisition.

When the gas to be measured flows into the detection chamber, the light energy trap formed by the speckle field at the entrance is the largest, and the particle size distribution interval peak value of the bound particles determined by the size of the energy trap is the largest, and the particles that meet the requirements are easier to be bound. Particles that cannot be bound continue to flow forward and enter the next speckle field. Therefore, particles satisfying different particle size intervals are bound in different areas of the detection chamber, and by comparing with the calibration values made in Example 1, the number and particle size distribution of bound particles in different areas can be obtained respectively, Thus, the particle concentration in the gas to be measured can be obtained.

In the embodiment shown in FIG. 5 , after sampling for a period of time, stop feeding the gas and turn off the laser, so that the binding force to the bound particles disappears. At this time, no particles are bound, and the particles can be captured again. Such recycling, do not need to replace the filter paper.

Embodiment 3, the PM2.5 particle measurement device and its measurement method based on the spatial optical lattice energy trap produced by the orthogonal grating

6 is a schematic structural diagram of a PM2.5 particle measuring device based on a spatial optical lattice energy trap generated by an orthogonal grating according to Embodiment 3 of the present invention. As shown in Figure 6, the device of this embodiment 3 includes a laser 1, a detection cavity 4, a CCD 6, a plano-convex lens 7, an orthogonal grating 8, an optical beam splitter 9, a white light source 10, a first objective lens 11, and a second objective lens 12. Optical filter 13.

In the embodiment shown in Figure 6, the laser 1 is used to emit a parallel laser beam, and the propagation direction of the laser beam is defined as the x direction. In this embodiment, the x direction is the horizontal direction; the flow direction of the gas to be measured is the y direction , in this embodiment, the y direction is a vertical direction, which is perpendicular to the x direction. The laser beam emitted by the laser 1 is condensed by the plano-convex lens 7 and irradiated on the orthogonal grating 8 to generate diffracted light. The optical beam splitter is located between the orthogonal grating 8 and the first objective lens 11, and the The 0th-order and 1st-order diffracted light generated by the grating 8 passes through the beam splitter 9 and enters the first objective lens 11, and then converges to the inner area of the detection cavity 4 through the first objective lens 11 to form a spatial optical lattice. It contains a large number of energy traps, which can bind part of the particles. The detection cavity 4 is used to accommodate the gas to be measured, and its center in the horizontal direction is located on the image plane of the first objective lens 11 .

The white light source 10 is used to emit an illuminating light, the illuminating light is reflected by the light beam splitter 9 and then passes through the first objective lens 11 to irradiate the spatial light lattice area, and the transmitted light is filtered by the second objective lens 12 After slice 13 is received by CCD6.

In the embodiment shown in FIG. 6 , the laser 1 is a semiconductor laser with a wavelength λ of 532 nm and a beam width D of 2.6 mm, which emits a continuous laser beam. The spacing of the orthogonal grating 8 is 20 μm. After the laser passes through the orthogonal grating, diffracted light will be generated, and the higher-order diffracted light will be diverged. The 0-order and 1-order diffracted light will pass through the dichroic prism and be converged by the first objective lens 11 to form a spatial light crystal. Grid, which contains many energy traps.

In the embodiment shown in FIG. 6 , the second lens 12 , the optical filter 13 and the CCD 6 are placed in such a way that their axes coincide with the x-axis, and the x-axis is the laser propagation direction. Wherein the optical filter 13 is located between the second lens 12 and the CCD6, and is used to filter most of the light emitted by the laser.

In the embodiment shown in Figure 6, since the size of the energy trap is related to the laser wavelength, the distance from the first-order diffracted light to the x-axis, the waist radius of the first-order diffracted light, and the axis of the first-order diffracted light and the x-axis inclination parameter, by adjusting The laser wavelength, the distance from the first-order diffracted light to the x-axis, the waist radius of the first-order diffracted light, and the parameters of the inclination angle between the axis of the first-order diffracted light and the x-axis can obtain the required energy trap size.

In the embodiment shown in Figure 6, the gas containing particles (0.1 μm ~ 10 μm) of different sizes is sent into the detection cavity, as shown in Figure 6, in the spatial optical lattice area at the image plane, the particles Particles whose diameter is in the peak area of the bound particle size determined by the energy trap are easier to be bound, and particles of other sizes are not easy to be bound and flow out. The tethered image is received by the CCD. The image received by the CCD is input to the computer, and the size and quantity of the bound particles are identified through a specially written program, so that the number of particles of different sizes can be counted and the particle size distribution of the particles can be obtained. The mass corresponding to individual particles of different sizes is known, and the mass of particles of different particle sizes can be obtained by multiplying the mass by the corresponding quantity. Since not all sizes of particles are bound, the bound particles are close to the size of the optical energy trap and have an approximately normal distribution. Therefore, it is necessary to obtain the particle size of the bound particles by passing in particles of different sizes with a certain mass The diameter distribution and the weight of particles of each size are compared with the weight of each size of the gas passed in, and the percentage of the bound particles of each size in the size of the gas passed is obtained, so as to realize the calibration of the device.

With the device of the present invention, the size of the optical energy trap is related to the laser wavelength, the distance from the first-order diffracted light to the x-axis, the waist radius of the first-order diffracted light, and the axis of the first-order diffracted light and the x-axis inclination parameter. By adjusting the laser wavelength, a The distance from the first-order diffracted light to the x-axis, the radius of the first-order diffracted light waist, and the parameters of the inclination angle between the first-order diffracted light axis and the x-axis can be used to obtain a suitable light energy trap, so that the normal distribution peak of the size of the bound particles is close to 2.5 μm , and calculate the number of bound particles with a size less than or equal to 2.5 μm, multiply it by the weight of a single particle of the corresponding size and divide it by the percentage of the size captured, the weight of each size in the gas can be obtained. Add the weights of particles of all sizes to get the total weight of PM2.5 in the gas, and divide it by the volume of the gas to get the PM2.5 concentration.

In the embodiment shown in FIG. 6 , after sampling for a period of time, stop feeding the gas and turn off the laser, so that the binding force to the bound particles disappears. At this time, no particles are bound, and the particles can be captured again. Such recycling, do not need to replace the filter paper.

Example 4. Measuring device and method for measuring PM2.5 particles based on multi-channel hierarchical real-time measurement of spatial optical lattice energy trap

Fig. 7 is a schematic structural diagram of a measurement device for measuring tiny particles in real-time by multi-channel classification based on a spatial optical lattice energy trap according to Example 4 of the present invention. Multiple sets of devices shown in FIG. 6 are integrated together as sub-devices, and the size of the optical lattice energy trap of each sub-device is different. As shown in FIG. 7, the spatial optical lattice generated by each system is located in the detection cavity 4, The size of the energy traps of each device is different. The size of the energy traps generated by the speckle field at the airflow inlet is the largest, and the size of the energy traps decreases from the airflow inlet to the airflow outlet. Wherein the detection cavity 4 is shared, the laser 1, the CCD 6, the plano-convex lens 7, the orthogonal diffraction grating 8, the light beam splitter 9, the white light source 10, the first objective lens 11, the second objective lens 12 and the optical filter 13 are each Each system needs to be used separately.

In the embodiment shown in Fig. 7, the laser beam emitted by the laser 1 of each sub-device is converged by the plano-convex lens 7 and then irradiated on the orthogonal grating 8, and the generated 0-order and 1-order diffracted light passes through the optical beam splitter 9 , after the first objective lens 11 converges to the inner area of the detection cavity 4 to form an optical lattice and generate a large number of optical energy traps, which can bind particles in a certain size range. The illumination light from the white light source 10 passes through the first objective lens 11 after being reflected by the light beam splitter 9 , and irradiates the optical lattice area.

In the embodiment shown in Figure 7, different sub-devices use different laser wavelengths, distances from the first-order diffracted light to the x-axis, the waist radius of the first-order diffracted light, and the parameters of the inclination angle between the axis of the first-order diffracted light and the x-axis. The size of the energy trap is also different, which can bind particles in different size ranges, where the x-axis direction is the laser propagation direction. When the gas to be measured flows into the detection chamber, the size of the optical energy trap formed by the spatial optical lattice at the entrance is the largest, and the particle size distribution interval peak value of the bound particles determined by the size of the energy trap is the largest, and the particles that meet the requirements are easier to detect. The bound and unbound particles continue to flow forward and enter the next spatial light lattice field. Therefore, particles satisfying different particle size intervals are bound in different areas of the detection chamber, and by comparing with the calibration values made in Example 3, the number and particle size distribution of bound particles in different areas can be obtained respectively, Thus, the particle concentration in the gas to be measured can be obtained.

In the embodiment shown in FIG. 7 , after sampling for a period of time, stop feeding the gas and turn off the laser, so that the binding force to the bound particles disappears. At this time, no particles are bound, and the particles can be captured again. Such recycling, do not need to replace the filter paper.

Example 5. Measuring device and method for real-time measurement of PM2.5 particles based on the combination of spatial speckle field and spatial optical lattice energy trap

Fig. 8 is a schematic structural diagram of a multi-channel hierarchical real-time measurement device for measuring tiny particles based on the combination of the spatial speckle field and the spatial optical lattice energy trap according to Example 5 of the present invention. A plurality of devices shown in Figure 4 and Figure 6 are integrated together as sub-devices (respectively referred to as the first sub-device and the second sub-device), and the energy traps produced by each sub-device are of different sizes, as shown in Figure 8, Both the spatial speckle field and the spatial optical lattice are located in the detection cavity 4, and the size of the energy traps of each sub-device is different. The size of the energy trap at the airflow inlet is the largest, and the size of the energy trap decreases from the airflow inlet to the airflow outlet. . Wherein the detection cavity 4 is common, and the imaging lens 5 and CCD6 of a plurality of sub-assemblies as shown in Figure 4 are common, and a plurality of lasers 1, ground glass scattering sheet 2, light concentrator 3 as shown in Figure 4 Each sub-device needs to be used separately, a plurality of sub-device lasers 1', plano-convex lens 7, orthogonal grating 8, light beam splitter 9, white light source 10, first objective lens 11, second The objective lens 12, the optical filter 13 and the CCD6' also need to be used separately for each sub-assembly. That is, the detection cavity 4 is used to accommodate the gas to be measured, and its center in the horizontal direction is located on the image plane of the light converging device of the first sub-device, and is located on the image plane of the first objective lens of the second sub-device,

In the embodiment shown in FIG. 8 , the laser beam emitted by the laser 1 in each first sub-device that generates optical energy traps based on the spatial speckle field passes through the light scattering sheet 2 and then reaches the detection cavity 4 through the light concentrator 3 .

In the embodiment shown in FIG. 8, the laser beam emitted by the laser 1' in each second sub-device that generates optical energy traps based on the spatial optical lattice is condensed by the plano-convex lens 7 and then irradiated on the orthogonal grating 8, resulting in The 0th-order and 1st-order diffracted light passes through the optical beam splitter 9, and then converges to the inner area of the detection cavity 4 through the first objective lens 11 to form an optical lattice and generate a large number of optical energy traps, which can bind particles in a certain particle size range . The illumination light of the white light source 10 passes through the first objective lens 11 after being reflected by the light beam splitter 9, and is irradiated to the optical lattice area, and the light in the optical lattice area is received by the CCD 6' after passing through the second objective lens 12 and the optical filter 13.

In the embodiment shown in FIG. 8 , the size of the light energy traps generated by each sub-device is different, and the size decreases sequentially from the airflow inlet to the airflow outlet. When the gas to be measured flows into the detection chamber, the size of the optical energy trap at the entrance is the largest, and the particle size distribution interval peak value of the bound particles determined by the size of the energy trap is the largest, and the particles that meet the requirements are easier to be bound, but not bound The particles continue to flow forward and enter the next energy trap field. Therefore, particles satisfying different particle size intervals are bound in different areas of the detection chamber, and by comparing with the calibration values made in Example 3, the weights of bound particles in different areas can be obtained respectively.

In the embodiment shown in Figure 8, after sampling for a period of time, the gas flow is stopped, and the laser is turned off, so that the binding force on the bound particles disappears. At this time, no particles are bound, and the particles can be captured again. Such recycling, do not need to replace the filter paper.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included in the protection scope of the present invention.

Claims (17)

1. the determinator of the granule density in a measurement gas, for measuring the concentration of the particle in predetermined particle diameter interval in gas to be measured, it is characterized in that, this device comprises laser instrument (1), diffuser (2), optical concentrator (3), test chamber (4), imaging len (5) and CCD (6), and

Described laser instrument (1) is for launching a collimated laser beam, this collimated laser beam incides described test chamber (4) via described optical concentrator (3) again after described diffuser (2) scattering, Space speckle field is formed in described test chamber (4), this Space speckle field comprises energy trapping

Described test chamber (4) is for holding gas to be measured, and be positioned in the picture plane of described optical concentrator (3), partial particulate in described gas to be measured is fettered by described energy trapping, the domain size distribution of this bound particle is relevant to the size of described energy trapping on the direction of propagation perpendicular to described laser beam, can measure the concentration of the particle in predetermined particle diameter interval in described gas to be measured according to the Number and size distribution of the particle of this size in bond;

The light of the surface scattering of described bound particle is received by described CCD (6) after described imaging len (5), by processing the image received by CCD (6), identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

2. the determinator of the granule density in measurement gas as claimed in claim 1, it is characterized in that, the aperture scale of the wavelength of the laser beam that described laser instrument is launched, distance between described optical concentrator and described picture plane and described optical concentrator can regulate, to make the domain size distribution of required particle in bond can the domain size distribution peak value region of particle in bond what determined by energy trapping size.

3. the determinator of the granule density in measurement gas as claimed in claim 2, it is characterized in that, described predetermined particle diameter interval is that diameter is less than or equal to 2.5 microns.

4. the determinator of the granule density in measurement gas as claimed in claim 3, is characterized in that, the aperture scale Da of the wavelength X of described laser beam, the distance Za between optical concentrator and described picture plane and described optical concentrator meets value be in the peak region in required size up interval.

5. the determinator of the granule density in measurement gas as claimed in claim 1, it is characterized in that, described imaging len and CCD modes of emplacement are the xy plane orthogonal that its axis and x direction and y direction are formed, wherein x direction is the direction of propagation of described laser beam, and described y direction is gas flow to be measured.

6. the multi-channel measuring device of the granule density in a measurement gas, for measuring the concentration of the particle in multiple predetermined particle diameter interval in gas to be measured, it is characterized in that, comprise multiple sub-device, every sub-device comprises laser instrument (1,1 '), diffuser (2,2 '), optical concentrator (3,3 '), multiple sub-device shares test chamber (4), an imaging len (5) and a CCD (6), and

The laser instrument of described every sub-device is for launching a collimated laser beam, the optical concentrator of this collimated laser beam again via this sub-device after the diffuser scattering of this sub-device incides described test chamber, multiple Space speckle field is formed in described test chamber, described Space speckle field comprises energy trapping

Described test chamber is for holding gas to be measured, its horizontal direction is centrally located in the picture plane of the optical concentrator of described every sub-device, what the particle diameter in described gas to be measured was in that described multiple energy trapping size determines can the particle in domain size distribution peak value region of bound particle be fettered by the energy trapping of each Space speckle field, the Number and size distribution of the particle of this multiple size in bond can be measured with the concentration of the particle measuring multiple predetermined particle diameter interval in described gas to be measured

Wherein, the aperture scale of described every the optical maser wavelength of sub-device, the distance between optical concentrator and described picture plane and this optical concentrator can regulate, to make the domain size distribution of required particle in bond can the domain size distribution peak value region of particle in bond what determined by energy trapping size;

The light of the surface scattering of the particle of described bound multiple size is received by described CCD (6) after described imaging len (5), by processing the image received by CCD (6), identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

7. the multi-channel measuring device of the granule density in measurement gas as claimed in claim 6, it is characterized in that, the modes of emplacement of described imaging len and CCD is the xy plane orthogonal that its axis and x direction and y direction are formed, wherein x direction is the direction of propagation of the laser beam of described multiple sub-device, and described y direction is gas flow to be measured.

8. the determinator of the granule density in a measurement gas, for measuring the concentration of the particle in predetermined particle diameter interval in gas to be measured, it is characterized in that, comprise laser instrument (1), test chamber (4), CCD (6), plano-convex lens (7), orthogonal grating (8), beam splitter (9), white light source (10), the first object lens (11) and the second object lens (12)

Described laser instrument is for launching a collimated laser beam, described laser beam is irradiated on described orthogonal grating after described plano-convex lens is assembled, produce 0 grade and 1 order diffraction light converge to the interior zone of described test chamber through described first object lens, form spatial light lattice, energy trapping is comprised in this spatial light lattice, this energy trapping can fetter partial particulate, the domain size distribution of this bound particle is relevant to the size of described energy trapping, the concentration of the particle in predetermined particle diameter interval in described gas to be measured can be measured according to the Number and size distribution of the particle of this size in bond,

Described test chamber is for holding described gas to be measured, its horizontal direction is centrally located in the picture plane of described first object lens, described optical maser wavelength, first-order diffraction light can regulate to the distance of x-axis, first-order diffraction light beam waist radius and first-order diffraction optical axis and x-axis dip angle parameter, to make the domain size distribution of required particle in bond can the domain size distribution peak value region of particle in bond what determined by energy trapping size, wherein x-axis direction is the direction of propagation of the laser beam that described laser instrument is launched

Described beam splitter (9) is positioned between described orthogonal grating (8) and described first object lens (11), described in 0 grade that is produced by orthogonal grating (8) and 1 order diffraction light transmission, beam splitter (9) incides described first object lens (11)

Described white light source (10) is for launching an illumination light, this illumination light through described beam splitter (9) reflection after through the first object lens (11), be irradiated to described spatial light lattice region, transmitted light is received by described CCD (6) after described second object lens (12), by processing the image received by CCD, identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

9. the determinator of the granule density in measurement gas as claimed in claim 8, it is characterized in that, also comprise one with the optical filter (13) of laser instrument phase co-wavelength, they are between described second object lens and CCD, for filtering the light sent by laser instrument.

10. the multi-channel measuring device of the granule density in a measurement gas, for measuring the concentration of the particle in multiple predetermined particle diameter interval in gas to be measured, it is characterized in that, comprise multiple sub-device, every sub-device comprises laser instrument (1), CCD (6), plano-convex lens (7), orthogonal grating (8), beam splitter (9), white light source (10), the first object lens (11) and the second object lens (12), multiple sub-device shares a test chamber (4), and

The laser instrument of described every sub-device is for launching a collimated laser beam, described laser beam is irradiated on the orthogonal grating of this sub-device after the plano-convex lens of this sub-device is assembled, first object lens of 0 grade that produces and this sub-device of 1 order diffraction light process converge to the interior zone of described test chamber, form multiple spatial light lattice, energy trapping is comprised in this spatial light lattice, this energy trapping can fetter partial particulate, the domain size distribution of this bound particle is relevant to the size of described energy trapping, the concentration of the particle in predetermined particle diameter interval described in described gas to be measured can be measured according to the Number and size distribution of the particle of this size in bond,

Described test chamber is for holding described gas to be measured, and be positioned in the picture plane of the first object lens of described every sub-device, the optical maser wavelength of described every sub-device, first-order diffraction light can be conditioned to the distance of x-axis, first-order diffraction light beam waist radius and first-order diffraction optical axis and x-axis dip angle parameter, to make the domain size distribution of required particle in bond can the domain size distribution peak value region of particle in bond what determined by energy trapping size, wherein x-axis direction is the direction of propagation of the laser beam of described multiple sub-device

Described beam splitter (9) is positioned between the orthogonal grating (8) of this sub-device and first object lens (11) of this sub-device, described in 0 grade that is produced by this orthogonal grating (8) and 1 order diffraction light transmission, beam splitter (9) incides first object lens (11) of this sub-device

Described white light source (10) is for launching an illumination light, this illumination light after beam splitter (9) reflection of this sub-device through first object lens (11) of this sub-device, be irradiated to described spatial light lattice region, transmitted light is received by the CCD of this sub-device after described second object lens, by processing the image received by described CCD, identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

The multi-channel measuring device of the granule density in 11. measurement gas as claimed in claim 10, it is characterized in that, every sub-device also comprise one with the optical filter (13) of laser instrument phase co-wavelength, between its second object lens at this sub-device and CCD, for filtering the light that major part is sent by laser instrument.

The multi-channel measuring device of the granule density in 12. 1 kinds of measurement gas, for measuring the concentration of the particle in multiple predetermined particle diameter interval in gas to be measured, it is characterized in that, comprise at least one first sub-device and at least one second sub-device, wherein, first sub-device comprises laser instrument (1), diffuser (2), optical concentrator (3), imaging len (5) and CCD (6), second sub-device comprises laser instrument (1), plano-convex lens (7), orthogonal grating (8) and the first object lens (11), described first sub-device and the second sub-device share a test chamber (4), and,

Described test chamber is for holding gas to be measured, and its horizontal direction is centrally located in the picture plane of the optical concentrator of described first sub-device, and is positioned in the picture plane of the first object lens of described second sub-device,

The laser instrument of described first sub-device is for launching a collimated laser beam, this collimated laser beam incides described test chamber via the optical concentrator of this first sub-device again after the diffuser scattering of this first sub-device, Space speckle field is formed in described test chamber, this Space speckle field comprises energy trapping, partial particulate in described gas to be measured is fettered by described energy trapping, the domain size distribution of this bound particle is relevant to the size of described energy trapping on the direction of propagation perpendicular to described laser beam, the concentration of the particle in predetermined particle diameter interval in described gas to be measured can be measured according to the Number and size distribution of the particle of this size in bond,

The aperture scale as the distance between plane and this optical concentrator of the optical maser wavelength of described first sub-device, optical concentrator and the first sub-device can regulate, interval to make described particle in bond be of a size of multiple described predetermined particle diameter,

The laser instrument of described second sub-device is for launching a collimated laser beam, described laser beam is irradiated on the orthogonal grating of described second sub-device after the plano-convex lens of described second sub-device is assembled, 0 grade that produces and 1 order diffraction light converge to the interior zone of described test chamber through the first object lens of described second sub-device, form spatial light lattice, energy trapping is comprised in this spatial light lattice, this energy trapping can fetter partial particulate, the domain size distribution of this bound particle is relevant to the size of described energy trapping, the concentration of the particle in predetermined particle diameter interval described in described gas to be measured can be measured according to the Number and size distribution of the particle of this size in bond,

The optical maser wavelength of described second sub-device, optical lattice place first-order diffraction light can regulate to the distance of x-axis, first-order diffraction light beam waist radius and first-order diffraction optical axis and x-axis dip angle parameter, to make the domain size distribution of required particle in bond can the domain size distribution peak value region of particle in bond what determined by energy trapping size, wherein x-axis direction is the direction of propagation of the laser beam of described multiple sub-device

The light of the surface scattering of described bound particle is received by described CCD after described imaging len, by processing the image received by described CCD, identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

The multi-channel measuring device of the granule density in 13. measurement gas as claimed in claim 12, it is characterized in that, described imaging len and CCD modes of emplacement are the xy plane orthogonal that its axis and x direction and y direction are formed, wherein x direction is the direction of propagation of described laser beam, and described y direction is gas flow to be measured.

The multi-channel measuring device of the granule density in 14. measurement gas as claimed in claim 12, it is characterized in that, described second sub-device also comprises beam splitter (9), white light source (10), the second object lens (12) and optical filter (13) and CCD (6)

Described beam splitter (9) is positioned between described orthogonal grating (8) and described first object lens (11), described in 0 grade that is produced by orthogonal grating (8) and 1 order diffraction light transmission, beam splitter (9) incides described first object lens (11)

Described white light source (10) is for launching an illumination light, this illumination light through described beam splitter (9) reflection after through the first object lens (11), be irradiated to described spatial light lattice region, transmitted light is received by described CCD after described second object lens, by processing to the image received by described CCD the Number and size distribution obtaining particle in bond, thus calculate the concentration of the particle of described multiple predetermined particle diameter distribution.

The multi-channel measuring device of the granule density in 15. measurement gas as claimed in claim 14, it is characterized in that, also comprise one with the optical filter (13) of laser instrument phase co-wavelength, they are between described second object lens and CCD, for filtering the light that major part is sent by laser instrument.

The assay method of the granule density in 16. 1 kinds of measurement gas, for measuring the concentration of the particle in predetermined particle diameter interval in gas to be measured, is characterized in that, comprising the steps:

Launch a collimated laser beam, this collimated laser beam is made after assembling, to incide a test chamber again after a diffuser scattering, Space speckle field is formed in described test chamber, this Space speckle field comprises energy trapping, partial particulate in described gas to be measured is by described Space Speckle field containment

Measure the Number and size distribution of this bound particle, thus measure the concentration of the particle of the distribution of predetermined particle diameter described in described gas to be measured,

The light of the surface scattering of the particle of described bound multiple size is received by a CCD, by processing the image received by described CCD, identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.

The assay method of the granule density in 17. 1 kinds of measurement gas, for measuring the concentration of the particle in predetermined particle diameter interval in gas to be measured, is characterized in that, comprising the steps:

Launch a collimated laser beam, this laser beam is irradiated on an orthogonal grating after assembling and produces 0 grade and 1 order diffraction light, make this diffraction light converge to the interior zone of a test chamber again, form spatial light lattice, comprise energy trapping in this spatial light lattice, can partial particulate be fettered

Measure the Number and size distribution of this bound particle to measure the concentration of the particle of the distribution of predetermined particle diameter described in described gas to be measured,

Launch an illumination light, this illumination is to described spatial light lattice region, receive by the light of described spatial light lattice region transmission by a CCD, by processing the image received by described CCD, identify size and the quantity of bound particle, thus add up the quantity of the particle of different size, obtain the domain size distribution of particle.