ISO 5311:2026

This document specifies two methods for the determination of the bulk density (tapped) of solid fertilizers:

• the machine-tapping method (method 1);
• the hand-tapping method (method 2).

These methods are applicable to dry fertilizers only.

Neither method is suitable for materials which contain a large proportion of particles exceeding 5 mm in diameter.

Method 2 is applicable only to spherical granules and to prills. It is not applicable to sharp-edged grains.

NOTE            Because of the differences in tapping technique, the two methods will not necessarily give the same value for the bulk density (tapped).