GB/T 3781.5 - 2019 Focus on the determination of coarse particle content of acetylene carbon black. The standard clearly explains from sample preparation, selection of screening instruments, to specific screening operation procedures, clarifies key parameters such as screening time, vibration screen Frequency, and calculation method of coarse particle results. Coarse particle content affects acetylene carbon black mass and application performance. This standard provides a unified testing specification for acetylene carbon black production enterprises, Quality inspection organizations and downstream application industries, helps to accurately control product mass, ensures its stable application in batteries, conductive rubber and other fields, and promotes the development of acetylene carbon black industry testing standardization.