The densities of powdered, granular of flaked materials are highly dependent on the manner in which the particles are packed together. During tapping, smaller particles distribute into the spaces between larger particles. Gradually particles pack more efficiently, the powder volume decreases and the tap density increases, often by 50% to 100%.
For this measurement, Quantachrome has developed two instruments which conform to the British Pharmacopoeia method for Apparent Volume and ASTM standard test methods B527, D4164 and D4781 for Tap Density. These two models, the Autotap and the two sample Dual Autotap, automate the required procedures to provide accurate, reproducible values.
