With the development of synthetic diamond technology, the size of the synthetic cavity becomes larger as well as the one of synthetic diamond equipment. The conversion rates of cavity are compared on the basis of the same quality controlling parameters and the adjustment of synthetic process with the same formula, the same batch of raw materi al, and the different cavities in the same assembling way. The products quality of cavity is also compared on the basis of controlling the conversion rate. With such two compari sons, the final conclusion is given that the synthetic cavity within a certain range （φ53） is helpful to improve the yield on the existing technology condition, and it has little effect on the synthesis performance; as if it is beyond a certain range （φ55）, it would seriously affect the synthesis performance, which could bring side influence on the economic benefits.
Concentration degree of granularity