What is equivalent particle size?What is D50?What is D97?

What is equivalent particle size?

The shape of the actual particle is usually non-spherical. When a particle has the same or similar physical properties as the homogeneous spherical particle, we use the diameter of the spherical particle to represent the diameter of the actual particle, which is called the equivalent particle size. According to different measurement methods, there are different equivalent particle sizes, such as:

(1) Equivalent volume particle size: that is, the diameter of a homogeneous spherical particle with the same volume as the measured particle.

(2) Equivalent settling velocity particle size: that is, the diameter of homogeneous homogeneous particles with the same settling velocity as the measured particles. Particle size measured by gravity sedimentation method and centrifugal sedimentation method is equivalent sedimentation velocity particle size, also known as Stokes diameter.

(3) Equivalent resistance particle size: that is, the diameter of homogeneous spherical particles with the same resistance as the measured particles under certain conditions. The particle size measured by the Coulter method is the equivalent resistance particle size.

(4) Equivalent projected area particle size: that is, the diameter of the desired particle with the same projected area as the measured particle. Particle size measured by image method is equivalent projected area particle size.

7. D50, what is the most frequent particle size?

(1) D50: also known as median diameter or median particle size, refers to the corresponding particle size value when the cumulative distribution percentage reaches 50%. This is a typical value for particle size, which accurately divides the population into a second class, meaning that 50% of the particles have a size above this value and 50% of the particles have a size below it. If the D50 of a sample is 5μm, it means that 50% of the particles with a particle size greater than 5μm and 50% of the particles with a particle size smaller than 5μm comprise the sample.

(2) The most frequent particle size: the particle size corresponding to the highest point of the frequency particle size distribution curve is called the most frequent particle size.

8. What is D97? What does it do?

D97 refers to the corresponding particle size when the cumulative distribution percentage from small to large reaches 97% in the particle size distribution. That is, the number of particles with particle size less than D97 accounts for 97% of the total number of particles in a powder. It is usually used to represent the coarse end particle size index of powder, which is a focus of attention in the production and application of powder. Similarly, some industries use D90, D95, D98 equivalent.