What does particle size distribution mean? What do D10, D50, and D90 represent?

The size of particles is referred to as "grain size" or "particle size," also commonly called "diameter." When a measured particle's certain physical characteristic or behavior most closely matches that of a homogeneous sphere (or ensemble) of a specific diameter, the diameter of this sphere (or ensemble) is taken as the equivalent grain size (or particle size distribution) of the measured particle. Of course, for non-spherical particles, the grain size is related to the measurement reference and statistical method used, meaning that the grain size can only be "equivalent."

The percentage (or cumulative percentage) of particles in different particle size intervals relative to the total quantity of the powder is referred to as the frequency particle size distribution (or cumulative particle size distribution). The y-axis represents the particle size composition calculated based on different criteria, which can be the percentage or cumulative percentage of number, length, area, or volume. The x-axis represents the particle size values calculated based on different criteria. D10, D50, and D90 can reflect the uniformity of the powder and are also known as indicators of the powder's cumulative distribution.

D50: Also known as the median particle size, D50 refers to the particle size value at which the cumulative distribution percentage reaches 50%. This is a typical value representing particle size, precisely dividing the total population into two equal parts. That means 50% of the particles have a size larger than this value, and 50% are smaller. If a sample has a D50 = 5μm, it indicates that among all particles composing the sample, 50% have a diameter greater than 5μm, and 50% have a diameter less than 5μm. D50 is commonly used to represent the average particle size of a powder.

D90: Refers to the particle size value at which the cumulative distribution percentage from smallest to largest reaches 90% in the particle size distribution. It signifies that in a given powder, 90% of the particles by number (or volume, depending on the measurement basis) have a size smaller than this value. It is typically used as an indicator for the coarse end of the particle size distribution and is a key focus in powder production and application. Similarly, some industries may use D95 or D97 values, which have similar physical meanings to D90.

D10: Refers to the particle size value below which 10% of the cumulative distribution lies, essentially the opposite of D90. In practical applications, these three parameters carry significant importance. For example, in the pharmaceutical industry, knowing the particle size distribution of a drug can provide insights into its efficacy and potential side effects. Moreover, in environmental protection fields, particle size distribution is also a critical metric for air and water quality monitoring. In summary, D10, D50, and D90 are three very important parameters in particle size distribution, each indicating the distribution of particles within different intervals. The size and distribution of micro-particles play a broad role in daily life and industrial production, directly impacting industrial processes, product quality, energy consumption, and the safety of production processes. Therefore, accurately and conveniently measuring the size and diameter (particle size) of micro-particles and obtaining the particle size distribution function is highly meaningful.