Answers to frequently asked questions about particle size analyzers(3)

What are the methods of expressing the particle size distribution?

(1) Table method: the method of listing all particle sizes and their corresponding percentages in the table, with two types of interval distribution and cumulative distribution.

(2) Graphical method: the method of expressing the particle size distribution by means of frequency distribution curve and cumulative distribution curve.

(3) Function method: the method of expressing the particle size distribution in the form of mathematical functions. Common distribution functions include normal distribution function, lognormal distribution function, R-R distribution function, etc.

What is the significance of granular testing?

Particle size has a major impact on the performance of powder materials, such as the strength and water demand of cement, the adhesion and covering rate of paint, the capacity of lithium batteries, the curative effect of drugs, the filtration efficiency of filter materials, the permeability and correction of magnetic materials. Resistivity, effectiveness and residue of pesticides, etc., are closely related to particle size. The particle size test is to see whether the particle size of such materials reaches the standard, whether it meets the quality and user requirements.

Why use equivalent particle size?

Only circles and spheres have diameters, and the concept of diameter is used to describe their size. So, is it feasible to directly use the diameter (particle size) to represent the size of the actual particle? It is not feasible, because the actual particles (especially solid particles) are usually not round and spherical, so the particle size cannot be directly used to describe its size, so the concept of equivalent particle size is introduced in the particle size test.