Part 3 of GB/T 5061-1998 Determination of Loose Bulk Density of metal powders by vibration funnel method. It clarifies the principle of measuring Loose Bulk Density by vibrating the funnel to make the powder flow into a specific container. Specifies the technical requirements for instruments and equipment such as vibration funnel and receiving container. Specifies the preparation of metal powder samples, including the collection and pretreatment of the powder. Specifies the test conditions such as vibration Frequency and time, as well as the operation points of the powder flow into the container process and the calculation method for the measurement of Loose Bulk Density. This standard provides a unified specification for the determination of Loose Bulk Density of metal powders, which is of great significance to the powder metallurgy and other industries to control the mass of products.