CN2612943Y - Micro particle graininess laser imaging measuring apparatus - Google Patents

Abstract

A laser imaging measurement device for particle size of microparticles, characterized in that it includes a laser power supply 1, a laser device 2, a cylindrical mirror 3 and a convex lens 4 for converting the light source into a sheet light source, and an irradiation measurement cylinder containing dispersing diluent and microparticles to be measured 8. The irradiated area 6 that accepts the sheet light source in the irradiation measuring cylinder 8, the optical microscope magnifying glass 10 that magnifies the scattered light spot of the particles, the CCD image sensor 11 that takes the particle light spot image, collects the CCD video signal and converts it into A data acquisition card 9 for the digital image signal, a computer 13 for processing the digital image signal and outputting particle size and particle size distribution. Its advantage is that it can measure the particle size of tiny particles in real time quickly and with high precision.

Description

Micro particle size laser imaging measurement device

technical field

The utility model relates to a laser imaging measuring device for the granularity of tiny particles, in particular to an imaging measuring device for measuring the granularity of tiny particles and their size distribution in engineering.

Background technique

The measurement of the particle size of tiny particles is widely used in engineering. Although there are many methods for particle size measurement, there is still a lack of an intuitive and quick measurement device.

Utility model content

The utility model aims to provide a laser imaging measuring device for the granularity of tiny particles, which can directly, quickly and accurately measure the granularity and size distribution of tiny particles.

In order to achieve this purpose, the utility model provides a laser imaging measurement device for tiny particles, which is characterized in that it includes a laser power supply 1, a laser 2, a cylindrical mirror 3 and a convex lens 4 for converting the light source into a thin sheet light source, and a dispersing diluent And the irradiation measurement cylinder 8 of the tiny particle to be measured, the irradiation area 6 located in the irradiation measurement cylinder 8 to accept the thin sheet light source, the optical microscope magnifying glass 10 for amplifying the scattered light spot of the particle, and the CCD image sensor for taking the particle light spot image 11. A data acquisition card for collecting CCD video signals and converting them into digital image signals. 9. A computer 13 for processing digital image signals and outputting particle size and particle size distribution.

Furthermore, the laser power supply 1 is a pulsed laser power supply with a controllable pulse width.

And, the electrical connection relation of pulsed laser power supply is: the AC power supply connects the two input ends of the rectifier 14 through the transformer L, and the Vm end and the GND end of the capacitor C2, C3 and the stabilized voltage power supply 15 are connected between the two output ends of the rectifier 14 , the 5V voltage output terminals of the regulated power supply 15 are respectively connected in series with the six switching positions of the switch K1 through six resistors R1, R2, R3, R4, R5, R6, and the output terminals of the switch K1 are simultaneously connected to The RC, B and CLR ends of the monostable circuit 16, a capacitor C is also connected in series between the RC and the C terminals of the monostable circuit 16, and its A terminal is connected to the acquisition card 9 to receive the synchronous trigger signal, and the Q terminal is connected through the switch. K2, resistor R7 is connected to the base of the triode T, its collector is connected to the 5V output terminal of the regulated power supply 15 through the resistor R8, its emitter is connected to the GND terminal of the regulated power supply 15 through the light-emitting diode D and grounded, and the a terminal of the switch K2 It is connected between the 5V voltage terminal of the regulated power supply 15 and the resistor R8.

Moreover, a reflector 7 is provided in the measurement cylinder 8 opposite to and perpendicular to the irradiation direction of the sheet light source.

Moreover, the PCI bus 12 is used to connect the data acquisition card 9 and the computer 13 .

Moreover, the data acquisition card 9 is an OK30 video acquisition card.

This device can directly image particles. By changing the magnification of the optical magnifying glass, the device has a wide and variable field of view. The particle size range suitable for measurement can be from several μm to several mm, and the distribution of particle size can be obtained at the same time. . Since the device adopts high-speed data acquisition and image processing technology, the detection time of the sample is shortened by about 30 seconds, and the detection accuracy is better than 10% (when ≥ 10 μm), basically realizing the real-time measurement of the particle size of tiny particles.

Description of drawings

Fig. 1 is a schematic diagram reflecting the structure of the utility model as a whole.

Figure 2 is a circuit diagram of a pulse power supply for powering the laser.

Detailed ways

Preferred embodiments of the present utility model will be described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1 and Fig. 2, as shown in the embodiment therein, the laser imaging measuring device for micro particle particle size includes a laser power source 1, a laser device 2, a cylindrical mirror 3 and a convex lens 4 for converting the light source into a sheet light source, and a disperse diluent And the irradiation measurement cylinder 8 of the tiny particle to be measured, the irradiation area 6 located in the irradiation measurement cylinder 8 to accept the thin sheet light source, the optical microscope magnifying glass 10 for amplifying the scattered light spot of the particle, and the CCD image sensor for taking the particle light spot image 11. A data acquisition card for collecting CCD video signals and converting them into digital image signals. 9. A computer 13 for processing digital image signals and outputting particle size and particle size distribution.

A further technical solution may be: the laser power supply 1 is a pulsed laser power supply with a controllable pulse width.

A further technical solution can also be: the electrical connection relationship of the pulsed laser power supply is: the AC power supply is connected to the two input terminals of the rectifier 14 through the transformer L, and the two output terminals of the rectifier 14 are connected with capacitors C2, C3 and the voltage stabilized power supply 15 The Vm terminal and GND terminal of the stabilized voltage power supply 15 are respectively connected in series with the 6 switching positions of the switch K1 through 6 resistors R1, R2, R3, R4, R5, R6, and the switch The output terminal of K1 is connected to the RC, B and CLR ends of the monostable circuit 16 at the same time, and a capacitor C is also connected in series between the RC and C terminals of the monostable circuit 16, and its A terminal is connected to the acquisition card 9 to accept synchronous triggering Signal, the Q terminal is connected to the base of the triode T through the switch K2 and the resistor R7, its collector is connected to the 5V output terminal of the regulated power supply 15 through the resistor R8, and its emitter is connected to the GND terminal of the regulated power supply 15 through the light-emitting diode D and grounded , the terminal a of the switch K2 is connected between the 5V voltage terminal of the regulated power supply 15 and the resistor R8.

Moreover, a reflector 7 may be provided in the measurement cylinder 8 opposite to and perpendicular to the irradiation direction of the sheet light source.

The PCI bus 12 can be used to connect the data acquisition card 9 and the computer 13 .

The data acquisition card 9 can be an OK30 video acquisition card.

When implementing this technical solution, in order to facilitate the understanding of relevant technical features and on this basis, according to specific needs and implementation conditions, make a reasonable choice among equivalent technologies, especially the role and more specific content of relevant technical features The breakdown is as follows:

1. Light source: It is recommended to use a red semiconductor laser with an exit pupil power of 40mW and a wavelength of 635nm as the light source. Because the laser has the advantages of good directionality, concentrated beam, and high brightness, it can be used to irradiate the particles in the measured area, and a scattering spot image signal with better contrast can be obtained.

The beam emitted by the laser 2 is expanded by the cylindrical mirror 3 and then collimated by the convex lens 4 to convert it into a parallel sheet-shaped light source 5 to irradiate the particles in the measurement area 6 . The thickness of the sheet light source 5 is about 1mm, and the width is about 20mm. The advantages of the sheet light source 5 are: 1. Make the measurement area very thin, which is convenient for the optical measurement system to focus on the measurement area; 2. The focal length of the particles in the measurement area does not change much, so the particle size distortion is not large; The measurement area is very thin, and the possibility of particle spot overlap is reduced, which can reduce the error of analysis and calculation.

2. Measuring cylinder 8: used to hold the measured particles and disperse diluent. The wall of the measuring cylinder is made of transparent glass with a rectangular or circular cross-section. The section size is about 50×50mm or φ80mm, and the height is about 60mm. In order to avoid forming dark shadows on the backlight surface of the particle when the unidirectional light source is irradiated, so that the outline of the backlight surface of the particle is blurred, a reflector 7 is arranged in the vertical direction of the light source in the container (it can also be plated with mercury on the opposite wall of the measuring cylinder). The reflector 7 reflects the incident sheet light back along the original path, and illuminates the particles in the measurement area again, which can effectively improve the particle edge image. The function of the diluent reduces the cohesion of the particles, so that the particles can be fully dissolved and dispersed, which is convenient for measurement. Commonly used dispersing diluents include water, water + glycerin, ethanol, ethanol + glycerin, etc. The diluent itself should not have chemical and physical reactions with the sample, and it should be pure and free of impurities. Generally, distilled water is used.

3. Optical microscope magnifier 10: It consists of a general-purpose microscope magnifier. The optical magnification can be changed by adjusting the focal length or changing the lens. The magnification of the optical magnifier of this device is 10x, 50x, 100x, 200x. The appropriate lens can be selected according to the size of the particles to be measured. The optical microscope magnifier is directly connected to the CCD image sensor, and the particles are focused and imaged onto the CCD array.

4. The function of the CCD image sensor 11 is to capture the particle spot image. And convert it into video image signal output, it is one of the core components of this device. The device adopts a general-purpose 420-line (or 600-line) black-and-white camera with a shooting speed of 50 frames per second, an optical sensitivity of 0.05lux, and a signal-to-noise ratio of 52dB.

5. The function of the video image acquisition card 9 is to collect the output video signal of the CCD at high speed, convert it into a digital image signal, and transmit it to the computer for processing. This device can adopt OK30 video acquisition card, what it adopts is PCI bus 12, can realize the high-speed transmission and acquisition of data, can work in color mode or black and white mode. This device works in black-and-white mode, the grayscale resolution is 256 levels, and the acquisition speed is 50 frames per second.

6. The computer 13 is used as an image signal analysis and processing unit and a system control component to realize the control of the measurement process, the operation processing of the image signal and the display of the results. Due to the large amount of image signal processing, the computer used is required to have high data processing speed and large access capacity. A general-purpose PIV computer can be used, which can complete the shooting of one frame of image and the analysis and calculation of granularity within 30 seconds. The rapid real-time measurement of the particle size is basically realized. Since the computer and its program itself belong to the prior art, they will not be described one by one.

7. Pulse laser power supply. In order to overcome the image tailing caused by particle movement and the false increase of particles, this device uses a pulse power supply to supply power to the laser. The pulse power supply circuit is shown in Figure 2. The pulse laser power supply includes: transformer L, rectifier 14, three-terminal DC voltage regulator block 15 (chip model 7805), switches K1, K2, monostable circuit 16 (chip model 4538), triode T and light-emitting diode D. Its working principle is that when the synchronous trigger signal of the acquisition card arrives, the monostable circuit 4538 is triggered to flip, so that the Q terminal outputs a high level, and the semiconductor laser is driven by the current amplification of the triode T to generate an optical pulse output. When K2 is switched to the b terminal, it is pulsed light output, and the pulse width can be switched by K1. When K1 is at position R1, the pulse width is 0.2ms, and when it is at R2, R3, R4, R5, R6 position, then The corresponding pulse widths are 0.5ms, 1ms, 2ms, 5ms, and 10ms respectively; when K2 is switched to the lower end, it is continuous light output. Another advantage of using pulsed excitation is that the service life of the laser can be improved, but the power of the required laser is correspondingly increased.

The processing of image signals, the calculation of particle size and the statistics of particle size distribution are automatically completed by computer under the control of a special program. The software mainly includes the following functions: background noise threshold calculation and background noise subtraction, particle edge sharpening and edge extraction, binarization processing, particle recording and particle spot area calculation, particle size calculation and particle size distribution calculation , Display and print the results.

Apparently, the aforementioned computer programs are not within the scope of the present application.

It should be further stated that the preferred embodiments of the present utility model have been illustrated, and various changes or modifications made by those skilled in the art will not depart from the protection scope of the present utility model if they are the equivalent technology of this case.

Claims (6)

1. A laser imaging measuring device for microparticle particle size is characterized in that it includes a laser power supply 1, a laser device 2, a cylindrical mirror 3 and a convex lens 4 that convert the light source into a sheet light source, and contains a dispersing diluent and the irradiation of the microparticles to be measured. Measuring tube 8, the irradiation area 6 that is positioned in the irradiating measuring tube 8 to accept the sheet light source, the optical microscope magnifying glass 10 that magnifies the scattering spot of the particle, the CCD image sensor 11 that takes the particle spot image, collects the CCD video signal and A data acquisition card 9 for converting digital image signals, a computer 13 for processing digital image signals and outputting particle size and particle size distribution. 2. The imaging measurement device according to claim 1, characterized in that: the laser power supply 1 is a pulsed laser power supply with a controllable pulse width. 3. The imaging measurement device according to claim 2, characterized in that: the electrical connection relationship of the pulsed laser power supply is: the AC power supply connects the two input terminals of the rectifier 14 through the transformer L, and the two output terminals of the rectifier 14 are connected in parallel Capacitors C2, C3 and the Vm terminal and GND terminal of the voltage stabilizing power supply 15, the 5V voltage output terminals of the voltage stabilizing power supply 15 are respectively switched by 6 resistors R1, R2, R3, R4, R5, R6 and the switch K1 The positions are connected in series, the output end of the switch K1 is connected to the RC, B and CLR terminals of the monostable circuit 16 at the same time, and a capacitor C is connected in series between the RC and C terminals of the monostable circuit 16, and its A The terminal is connected to the acquisition card 9 to receive the synchronous trigger signal, the Q terminal is connected to the base of the triode T through the switch K2 and the resistor R7, its collector is connected to the 5V output terminal of the stabilized power supply 15 through the resistor R8, and its emitter is connected to The GND terminal of the regulated power supply 15 is grounded, and the a terminal of the switch K2 is connected between the 5V voltage terminal of the regulated power supply 15 and the resistor R8. 4. The imaging measurement device according to claim 1, 2 or 3, characterized in that: a mirror 7 is provided in the measurement cylinder 8 opposite to and perpendicular to the irradiation direction of the sheet light source. 5. The imaging measurement device according to claim 4, characterized in that: the data acquisition card 9 and the computer 13 are connected by a PCI bus 12. 6. The imaging measurement device according to claim 5, characterized in that: the data acquisition card 9 is an OK30 video acquisition card.