What is particle standard material?

The verification and calibration of the particle size analyzer can use certified particle size reference materials or general standards. Among them, CRM is set by authoritative departments, and the set value data is publicly released. The currently recognized absolute measurement method in the country is microscopy, and its scale can be traced back to the length standard. Usually the scale scale is 10um, and the minimum is 416nm.

In addition to having an accurate value, particle size reference materials also require ① good material stability and a stable particle size value within a certain period of time (such as 1 year); ② good monodispersity, that is, the smaller the coefficient of variation of the particle size distribution, the better. Usually The coefficient of variation of the primary standard is ≤3%,

The coefficient of variation of the secondary standard is between 3% and 8%; ③ The sphericity is good, and the circularity is required to reach 95%·98%.