Bulk Density: Tester

This measures the density after the container has been mechanically tapped (lifted and dropped) a specific number of times. The powder settles, eliminating air gaps.

| Hausner Ratio | Character of Powder | | :--- | :--- | | 1.00 – 1.11 | Excellent / Free Flowing | | 1.12 – 1.18 | Good | | 1.19 – 1.25 | Fair | | > 1.40 | Poor / Cohesive | bulk density tester

| Mistake | Consequence | Fix | | :--- | :--- | :--- | | Tapping too fast (>300 taps/min) | Powder fluidizes, giving false low density | Use 250–300 taps/min (USP allows 250±15) | | Reading volume before fines settle | 5–10% high tapped volume | Wait 10–15 sec after last tap | | Using cylinder with chipped rim | Leveling error >2% | Discard damaged cylinders | | Not correcting for temperature | Density changes ~0.1% per °C (air expansion) | Record room temp; use reference temp | | Using different funnel heights daily | Irreproducible LBD (±8%) | Fix funnel height permanently | This measures the density after the container has