Bulk density ASTM D1895 Method B – Bulk density measurement:

ASTM D1895 Method B is used to determine the Bulk density of powders that do not flow freely, but can nevertheless be transferred through a defined funnel opening into a measuring cylinder under gravity. The method is intended for powders that slight flow inhibition, coarser particles, irregular grain shapes or moderate bridging exhibit.

Method B closes the gap between:

• Method A (free-flowing powders)

• Method C (Powder with pronounced flow inhibition)

Test setup NIP-BDM1800B

The Bulk density test setup NIP-BDM1800B is constructed according to ASTM D1895 Method B and includes:

• Funnel assembly (Method B geometry): Stainless steel funnel with enlarged outlet opening and optimized cone angle to reduce bridging.

• Measuring cylinder (fixed volume): Precision stainless steel cylinder with calibrated internal volume according to ASTM tolerances.

• Tripod frame: Rigid vertical alignment between hopper and measuring cylinder for reproducible powder flow.

• Base plate with leveling feet: For precise horizontal alignment of the test setup.

• Analytical balance: Resolution ± 0.01 g for determining powder mass.

• Tools: Spatula, brush and scraper edge for sample handling and cleaning.

Operating principle

The powder is transferred under its own weight through the funnel into the measuring cylinder. The cylinder has a fixed volume, which is precisely defined by wiping it flush with the edge. The mass of the powder in the known volume yields the Bulk density.

Test procedure according to ASTM D1895 Method B

1. Preparation of the test setup

• Thoroughly clean and dry the bulk density test setup NIP-BDM1800B.

• Level precisely using a spirit level.

• Ensure that the funnel outlet is positioned centrally above the measuring cylinder.

2. Sample conditioning

• Bring the powder to laboratory room temperature (approx. 23 ± 2 °C).

• Homogenize the sample without altering the particle structure or moisture content.

3. Filling the funnel

• Close the funnel outlet with the sealing plate.

• Fill with powder to just below the top edge.

• Do not allow vibration or compression.

4. Initiation of powder flow

• Quickly remove the locking plate.

• Allow the powder to flow freely and undisturbed into the measuring cylinder.

• In case of temporary flow inhibition Do not tap or shake — Method B only allows free fall without mechanical assistance.

5. Leveling the measuring cylinder

• Excess powder with a straight edge flush with the cylinder edge wipe off.

• Perform a smooth, non-compacting movement.

6. Weighing

• Weigh the filled measuring cylinder (± 0.01 g).

• Subtract the empty weight of the cylinder to obtain the net mass of the powder.

7. Calculation of bulk density

Report results to three significant figures.

8. Repeatability

• Perform at least three measurements.

• Deviation between results ≤ ± 1 %.

Technical notes

• Method B is ideal for powders with moderate flow inhibition, e.g.:

  • coarser metal powders

  • irregularly shaped particles

  • slightly agglomerating materials

• The funnel of the NIP-BDM1800B is designed to reduce bridging without requiring mechanical support.

• Cleaning between tests prevents cross-contamination and ensures stable measurement results.

• Stainless steel construction offers high dimensional stability and corrosion resistance.

Evaluation

The bulk density determined according to ASTM D1895 Method B provides information about:

• Particle morphology and flow behavior

• Packing density under gravity

• Suitable for pressing, sintering or dosing processes

• Quality control and supplier comparison