GB/T 21649.2-2017 Particle size analysis image analysis method Part 2: Dynamic image analysis method GB/T21649.2-2017 |tt||Standard compression package decompression password: www.bzxz.net
This part of GB/T 21649 specifies methods for position control, image acquisition and analysis of moving particles in liquids, gases or conveying processes. When the particles in liquids, gases or on moving carriers are effectively dispersed, this method can measure the particle size and its distribution.

ICS19.120
National Standard of the People's Republic of China
GB/T21649.2—2017/ISO13322-2:2006Particle size analysis
Image analysis methods
Part 2: Dynamic image analysis
Particle size analysisImage analysis methods-Part 2: Dynamic image analysis methods（ISO13322-2:2006.IDT）
2017-02-28 Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of China
2017-09-01 Implementation
GB/T21649.2—2017/ISO13322-2:2006 Foreword
Normative references
Terms and definitions, symbols-
Terms and definitions
Particle motion
Particle positioning
Operation steps
Static image resolution
Calibration and traceability
Particle Degree grading and magnification
Particle edge
6 Sample preparation
Sampling and measurement variability
Appendix A (informative)
Recommended particle speed and exposure time
Recommended maximum particle size
Appendix B (informative)
Appendix C (informative) Typical examples of sample introduction and image acquisition systems References
GB/T21649.2—2017/1IS013322-2:2006GB/T21649 "Image analysis method for particle size analysis" has been or is planned to be published in the following parts: Part 1: Static image analysis method;
Part 2: Dynamic image analysis method.
This part is the second part of GB/T21649
This part is drafted according to the rules given in GB/T1.1-2009. This part uses the translation method and is equivalent to IS013322-2:2006 "Image analysis method for particle size analysis Part 2: Dynamic image analysis method".
The Chinese documents that have a consistent correspondence with the international documents referenced in this part are as follows: GB/T21649.1-2008 Image analysis method for particle size analysis Part 1: Static image analysis method (ISO13322-1:2004.MOD)
This part has made the following editorial changes:
Correct "multiple methods" in the scope of Chapter 1 of the international standard to "methods", and "these methods" to "this method". This part is proposed and managed by the National Technical Committee for Particle Characterization and Sorting and Screen Standardization (SAC/TC168). Drafting organizations of this part: Beijing Powder Technology Association, Beijing Physical and Chemical Analysis and Testing Center, Dandong Better Instrument Co., Ltd., National Non-metallic Mineral Deep Processing Product Quality Supervision and Inspection Center, China Machinery Productivity Promotion Center, Beijing Coast Hongmeng Standard Material Technology Co., Ltd., Chizhou Daheng Biochemical Co., Ltd., China National Institute of Metrology, Shanghai Spectris Instrument Systems Co., Ltd. (Malvern Instruments), National Center for Nanoscience and Technology, Shanghai Anlikang Scientific Instrument Co., Ltd. The main drafters of this part: Zhou Suhong, Zhang Tao, Zhang Lixin, Dong Qingyun, Gao Yuan, Yu Fang, Pan Junjie, Song Zhengqi, Hou Changge, Zhang Wenge, Qin Heyi, Liu Junjie, Fang Qin, Li Zhaojun, Wang Hai, Fang Rong, Ma Jiang, Li Li, Hou Zhiyun, Gao Jie, Qi Xiaoying, Zhang Chaoyi, Wang Xiaobing. 1
GB/T21649.2—2017/ISO13322-2:2006 Introduction
This part of GB/T21649 provides guidance for measuring and describing the particle size distribution of moving particles by image analysis. This method requires the use of technical means to effectively disperse and focus particles in liquids or gases, collect static images of moving particles, and analyze the images. This method is called dynamic image analysis.
There are many methods for image acquisition. Appendix C of this part of GB/T21649 introduces several typical methods. 1 Scope
GB/T21649.2—2017/1IS013322-2:2006 Particle size analysis
Image analysis method
Part 2: Dynamic image analysis method
This part of GB/T21649 specifies methods for position control, image acquisition and analysis of moving particles in liquids, gases or during transportation. This method can measure the particle size and its distribution when the particles in a liquid, gas or on a mobile carrier are effectively dispersed. 2 Normative references
The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all amendments) applies to this document ISO13322-1:2004 Particle size analysis - Image analysis methods Part 1: Static image analysis methods (Particle size analysis - Image analysis methods Part 2: Dynamic image analysis methods) 3 Terms and definitions Symbols
3.1 Terms and definitions
The following terms and definitions apply to this document. 3.1.1
Flow-cell
A measuring unit through which a mixture of fluid and particles flows. 3.1.2
Orifice tube
Orifice tube
A pipe with an orifice plate that allows a fluid containing dispersed particles to flow through a small hole. 3.1.3
sheath flow
clean fluid flowing around a fluid containing particles, guiding the particles into a specific measurement area3.1.4
particle illumination
particle illumination
continuous illumination of an image acquisition device with an electronic exposure time controller, or short-term illumination of a synchronized image acquisition device. 3.1.5
measurement volume
measurement area
area used for particle measurement in an image analyzer. 3.1.6
depth of field
area where the image sharpness reaches a preset effect, 3.1.7
image capture device
image capture device
area array camera or line array camera.
GB/T21649.2—2017/ISO13322-2:20063.2
The following symbols apply to this document.
The moving distance of a single particle in time t
The projected area of ​​particle i
The equivalent diameter of the projected area of ​​the particle measured by the binary imageExposure time
Particle velocity
Particle diameter
The equivalent diameter of the projected area of ​​the particle
The maximum Feret diameter of particle i
The minimum Feret diameter of particle i
The ratio of the measured particle diameter to the static particle diameterFigure 1 is a schematic diagram of dynamic image analysis.
Description:
Dispersed particles;
Particle motion control device;
Measurement area;
Light source:
Optical system:
Depth of field;
Image acquisition device:
Image analysis device;
Display.
Figure 1 Schematic diagram of a typical dynamic image analysis method 2 Particle movement
GB/T21649.2—2017/IS013322-2:2006 Particles can be introduced into the measurement area in the following three ways to keep the particles moving: a) through dynamic fluid introduction (such as particles in suspension, aerosol, catheter, air nozzle, sheath flow, flow or push-pull flow); through static fluid introduction, for example, in an injection or free fall system, the particles are oriented by external forces (such as gravity, static electricity) b)
Movement;
c) Introduction through a moving carrier (such as a conveyor belt). 4.3 Particle positioning
Introduce the particle into the measurement area and collect the image of the particle when it is in the object plane. The depth of the measurement area depends on the depth of field of the optical system used.
Figure 2 is a schematic diagram of the measurement area.
Description:
Light source;
Camera:
Measurement area.
Figure 2 Schematic diagram of the measurement area
As shown in Figure 3, the observation direction (parallel or vertical) affects the characterization of the particle size and shape, but this section does not consider the influence of the particle shape during the measurement process.
The image acquisition device should be focused to obtain a clear image of the moving particles in the fluid. The following methods are recommended: a) Adjust the position of the moving particle so that it only passes through the measurement area of ​​the image acquisition device; when the moving particle passes through the measurement area of ​​the image acquisition device, illuminate the particle with a stroboscopic light source (such as a flash lamp) and collect the image of the moving particle b)
particle.
GB/T21649.2—2017/IS013322-2.2006 Note:
Measurement area parallel to the particle movement direction; 2
Measurement area perpendicular to the particle movement direction?
Figure 3 Particle movement and observation direction
5 Operation steps
5.1 General
Modern image analyzers have a variety of algorithms to enhance image quality before analyzing images. As long as the measurement results can be traced back to the original image, the enhancement algorithm can be used.
5.2 Static image resolution
The resolution of the image collected by the dynamic image analysis system depends not only on its optical system (lens magnification and camera resolution), but also on the illumination system and the particle movement speed. When a spherical particle with a diameter of x moves at a speed, the center of the particle's projected area moves a distance α in time t, calculated according to formula (1), where t is the flashing time of the strobe light or the shutter time of the camera (see Figure A.1). a=uXt
Before appropriate grayscale processing, a should not exceed 0.5 pixels or α*(e-1) pixels, where e is the ratio of the measured particle diameter to the static particle diameter. The grayscale setting between the particle and the background should ensure that the diameter b measured by the binary image is the same as the diameter of the static particle. The resolution of the entire system is determined based on the particle size distribution and the preset confidence interval (see ISO13322-1:2004). 5.3 Calibration and traceability
The equipment needs to be calibrated before testing, and the pixels are converted into SI length units (such as nanometers, micrometers and millimeters). The calibration procedure should include a field of view uniformity test. The basic requirement of the calibration procedure is that all measured values ​​should be traceable to standard meters. The image analysis equipment can be calibrated using a certified standard micrometer to achieve particle image acquisition. Moving particles, especially small particles, may cause serious errors in particle size measurement results. It is recommended to calibrate the entire system with standard materials.
Calibration particles that cover the entire system dynamic range should be selected. It is recommended to calibrate the instrument with certified particles of three different particle size values, that is, to measure particles with particle sizes close to the upper limit, middle position and lower limit of measurement, respectively. 5.4 Particle size classification and magnification
When measuring particle size using image analysis, the theoretical limit of resolution is one pixel. Under the condition of a maximum resolution of one pixel, the particles are counted and stored one by one. In order to report the measurement results, it is necessary to define the particle size classification. The particle size classification is a function of the total number of particles, the dynamic range and the number of pixels contained in the smallest counted particle. It is advisable to convert the pixel size to the actual size before providing a quantitative analysis report of the particle size.
During the test, only some particles are actually measured, and large particles are more likely to hit the edge of the image frame. Therefore, the appropriate magnification should be selected to ensure that the longest diameter of the largest particle does not exceed one-third of the short side of the rectangular image frame of the test area (see Appendix B). Any errors due to loss of information about large particles at the edge of the image frame should be documented in the report. The optical resolution that can be used is generally better than the electronic resolution. 5 Particle edges
The edges of particles in the image should be defined by selecting an appropriate threshold value, which depends on the accuracy of the image analysis equipment. The threshold should be adjusted by comparing the processed binary image with the original grayscale image to ensure that these binary images accurately and reliably represent the original grayscale image.
5.6 Measurement
The measurement of particle parameters depends on the image analysis system used. The following indicators are mainly measured: a) the projected area of ​​each particle (A,) in pixels; b) the maximum size of each particle (maximum Feret diameter, Timax) in pixels; c) the minimum size of each particle (minimin) in pixels. A shape factor that is most easily distinguished can be defined. The projected area of ​​each particle can be converted to the area equivalent diameter I· calculated according to formula (2): /4A
6 Sample preparation
The number of particles in the dispersion medium should be controlled to ensure that the particle images do not overlap. 7 Sampling and measurement variability
Particle counting can be achieved while ensuring that no particles are lost or counted repeatedly. The minimum number of particles to be counted should be determined based on the particle size distribution and the set confidence interval (see ISO13322-1:2004). To increase the reliability of the measurement, the average diameter and standard deviation of multiple measurements can be statistically calculated. Typical examples of sampling and image acquisition systems are shown in Appendix C. ..(2)
GB/T21649.2—2017/IS013322-2.2006 Appendix A
(Informative Appendix)
Recommended particle speed and exposure time
There are some points that need special attention when using the dynamic image method to measure moving small particles. For a spherical particle with a diameter of I (pixels) and a speed of (pixels/second), the distance moved by the center of its projected area during the exposure time ts) is α (pixels), which is calculated according to formula (A.1): a=uXt
The particle diameter b (pixels) measured in the direction of motion is between (a+a) and (r-a), depending on the adopted reading value (see Figure A.1). Therefore, when a grayscale image of a moving spherical particle is collected and converted into a binary image using a preset value, the image shape is more like an oblong ellipse than a circle. The maximum size of the binary particle image is calculated according to formula (A.2): b=a+a
In order to make the measurement results of dynamic particles consistent with those of static particles, it is recommended that the difference between a and b is less than 0.5 pixels. Calculated according to formula (A.3):
a=uxto5
. (A.3)
However, if only large particles are measured (for example, larger than 10 pixels, the area equivalent diameter has a certain measurement error), the difference with b (the same as a)) is calculated according to formula (A.4) to formula (A.7): TA.ree
Among them, are
4XAreal
4XAmeas
. (A.6)
. (A.7)
are the area equivalent diameters of static particles and measured particles, respectively. Areal and Amc are the projected areas of static particles and measured particles, respectively.
The ratio e of the measured particle diameter to the static particle diameter is calculated according to formula (A.8): A
This equation can also be expressed as formula (A.9):
a=r(e2-1)
For example, when e is less than 1.1 (equivalent to a relative error of 10% in the particle diameter), the relationship between α and z is as shown in formula (A.10): a<0.21
Therefore, when the minimum measured particle diameter is 10 pixels, α can be up to 2 pixels, see formula (A.11): a=uXt<2.1
Figure A.1 illustrates the particle image and threshold, and Figure A.2 illustrates the extension of particles of arbitrary shape. 6
. (A.9)
. (A.11)
Description:
Distance moved during exposure time (pixels): Diameter measured by binary particle image (pixels); Movement direction and speed (pixels/s); Diameter of stationary particles (pixels):
Particle position at the beginning of image acquisition:
BParticle position at the end of image acquisition:
.A Threshold line:
Grayscale.
GB/T21649.2—2017/ISO13322-2:2006 Figure A.1 Particle image and reading valuewwW.bzxz.Net
GB/T21649.2—2017/ISO13322-2:2006 Note:
Maximum error caused by particle motion;
Projected area of ​​stationary particles;
Movement distance during exposure time (pixels); Movement direction and movement speed (pixels/second); Feret diameter of the projected area perpendicular to the movement direction; Particle position at the beginning of image acquisition;
Particle position at the end of image acquisition.
Figure A.2 The situation shown in Figure A.1 is extended to particles of arbitrary shapes. In Figure A.2, Aer is calculated according to formula (A.12):
Aerr=aXap
where I depends on the orientation of the particles relative to the direction of movement. e is calculated according to formula (A.13):
A real +Aerr
4xaxaF
元XrA.real
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.