(1) Laser method: advantages: easy operation, fast test speed, large test range, good repeatability and accuracy, and can realize on-line measurement and dry measurement. Disadvantages: The result is greatly affected by the distribution model, and the instrument cost is high.
(2) Dynamic image method: consists of a microscope, a high-speed camera, a sample dispersion system, a control system, and high-speed image analysis software. Advantages: The image of the particle is intuitive and clear, the operation is simple, the shooting and analysis speed is fast, the repeatability and the accuracy are good, the dry method can also be wet method, the maximum particle can be measured, and the shape analysis such as the circularity and the aspect ratio can be performed. Disadvantages: Analysis of fine particles (such as -2 μm) is not clear, the error is large, and the cost is high.
(3) Static image method: consists of microscope, camera and image analysis software. Advantages: low cost, simple operation, clear image, and can be analyzed for shape and shape such as circularity and aspect ratio. Disadvantages: The analysis is slow and it is not possible to analyze fine particles (eg -2 μm).
(4) Electron microscopy: A method of taking an image of a particle using an electron microscope (SEM or TEM) and then performing image analysis. Advantages: Accurate analysis of nano-particles and ultra-fine particles, clear image, visible surface texture and high resolution are standard methods for characterizing nano-material particle size. Disadvantages: The number of particles in a single image is small, the representativeness is poor, and the instrument is expensive.
(5) Photoresist method: Advantages: The test speed is fast, the number of particles in liquid or gas can be measured, the resolution is high, and the sample dosage is small. Disadvantages: The injection system is more complicated and does not apply to samples with a particle size of <1μm.
(6) Resistance method: Advantages: easy to operate, can measure the number of particles, the equivalent concept is clear, the speed is fast, and the accuracy is good. Disadvantages: It is not suitable for measuring ultra-fine samples and wide-distribution samples. It is more troublesome to replace small-pore tubes.
(7) Settlement method: advantages: easy to operate, the instrument can run continuously, the price is lower, the accuracy and repeatability are better, and the test range is larger. Disadvantages: Long test time, complicated operation, and the result is susceptible to environmental factors.
(8) Screening method: advantages: simple, intuitive, low equipment cost, commonly used for samples larger than 38 μm (400 mesh). Disadvantages: Can not be used for ultra-fine samples; the results are greatly affected by human factors and mesh deformation.
(9) Dynamic light scattering method: Dynamic light scattering method is a common method for testing the particle size distribution of nanomaterials. The nanoparticles are first placed in a suitable liquid (usually pure water) to form a suspension, and the nanoparticles in the suspension undergo irregular movement due to collision of thermal motion (Brownian motion) of the water molecules. When a horizontally polarized laser is incident on these particles, it will change at the moment of the induced scattered light intensity. The amplitude, frequency and other characteristics of these instantaneously varying scattered light signals are related to the particle size. The correlation calculation of these signals can obtain the particle size distribution of the rice particles. Advantages: Wide test range (from nanometer to micrometer), fast test speed, good repeatability and easy operation. Disadvantages: Testing wide-ranging nanomaterial errors and larger.
(10) Ultrasonic method: Advantages: The high-concentration slurry can be directly measured in the field without sampling. Disadvantages: lower resolution, poor accuracy and repeatability, and the result is greatly affected by environmental factors.
(11) Breathing method (Ferith method): Advantages: The instrument price is low, the sample is not dispersed, the dry powder can be directly measured, and the magnetic material powder can be measured. Disadvantages: Only the average particle size value can be obtained, and the particle size distribution cannot be measured.
The sensor faucet provide the most comfortable and convenient experience. No need to touch any handles, effectively preventing cross-infection after washing hands. 30-second timeout feature reduces water waste. It's widely used in shopping malls, restaurants, hospitals,hotels,bathrooms and ect.
Sensor Faucets,Sensor Bathroom Faucet,Motion Sensor Bathroom Faucet,Bathroom Touchless Sensor Faucet
Kaiping Yufa Sanitary Ware Co.,ltd , https://www.dlsen-faucet.com