Testing that Reaches the World
Density Testing
Apparent Density
Apparent Density is also referred to as True Density, Absolute Density, Real Density, and Skeletal Density.
Apparent Density is being determined by Helium Pycnometer. This technique excludes the pores as well as the void spaces between particles within the material. Given the technique used, some also refer to this test as “Helium Density.”
Apparent Density testing is performed on powders and other solid materials. The sample is first prepared with heat and/or vacuum, then helium gas fills the sample chamber and pressure is measured. The helium then enters another empty change and the pressure from both chambers is measured. The sample volume is calculated based on the pressures and the known weight of the sample; the density is then calculated.
Sample requirements for testing:
35 mL minimum, enough to fill a 10 cc cup.
Bulk Density
Mercury Porosimetry is a technique used to measure Bulk Density. Density is being determined by means of mercury; utilizing the total volume of the material including interstitial volume and pore volume.
Sample requirements for testing:
10 grams total, if possible. Material shall fit into a 0.5” diameter by 1” length sample tube for testing.
Tap Density
Tap Density is performed by mechanical means. The procedure calls for mechanically tapping a gradated cylinder containing the sample until there is no longer a change in volume. This technique is impacted by particle size distribution and shape, as well as interparticle voids.
The Tap Density test is common for packing and shipping of materials.
Sample requirements for testing:
20-100 grams of material