The main indicators are: BET specific surface area, ph, conductivity, sulfate, median diameter, oil absorption value, sieve residue, moisture, burning! The specifications of the particles are powder, microbeads, and lumps. The particle size is measured by the median diameter, and the unit is microns; the specific surface area is the external specific surface area and the internal specific surface area, and the unit is square meters per gram; the oil absorption value refers to the white content per gram. How much oil can carbon black absorb? The unit is milliliters per gram! The most important indicator is BET, moisture! The others are all secondary indicators. Different customers and different uses have different requirements!