Physical Measurements

Washington Mills offers a full range of physical measurement testing from: particle size analysis (Ro-tap, Coulter Counter and Microtrac), bulk density, specific gravity, magnetics, micro-hardness testing, and friability. Testing is available on a wide variety of materials including: abrasive, refractory, and ceramic grains and powders as well as many other materials.

Physical Measurement Testing Services

Particle Size Analysis

• Ro-tap Shaking Sieve Analysis
  Instrument: W.S. Tyler RX-29 Ro-Tap
  Measures Particle Size: Macro Grit 4 – 240 grit size or around 3500 – 45 microns
  Sieve analysis measures the particle size of dry grains and powders by measuring the weight of the particles that pass through a group of sieves. It is used to measure particle size of material that is larger than 45 microns. Our particle size analysis instrument is an automated Ro-tap shaking sieve machine.
• Coulter Counter
  Instrument: Beckman Coulter Multisizer 3
  Measures Particle Size: Micro Grit 240 – 1200F grit size or around 50-3 microns
  The particle size distribution (PSD) of smaller grains and powders are accurately measured on a Coulter Counter. The Coulter Counter gives volume % and number % size distributions, aspect ratio and sphericity of powders.
  The particle size distribution of powders / micro-grits is measured on a Coulter Counter in order to give the most accurate particle count and particle size distribution.
• Microtrac
  Instrument: Leeds and Northrup X100 Microtrac
  Measures Particle Size: Micro Grit 240 – 1200F grit size or around 50-3 microns
  Microtrac particle size analysis uses laser light technology to provide accurate, reliable particle size distribution data. Microtrac provides volume, number, area distributions, percentile and summary data. Microtrac’s light scattering technology is the most accurate technology for measuring particle size distribution of very small particle sizes.
• Wet Sieve Analysis
  Wet sieve (or wet screen) analysis can be used for powders that are 45 microns or less. The powders are washed through sieves, dried and weighed.

Bulk Density

We offer bulk density testing on materials in order to determine the weight per unit volume of the material, grain or powder. Bulk density measures the mass of the material divided by the volume that the particles occupy and it is measured in g/cm3.

Specific Gravity

Specific gravity measures the ratio of the weight of any volume of a substance to the weight of an equal volume of another substance taken as a standard at a constant temperature. We measure specific gravity using a Micromeritics Multivolume Helium Pycnometer.

Magnetics

We use a Buck Magnetic Analyzer to measure for the % magnetics (free iron) in samples of grains and powders.

Friability

Friability is the ability to breakdown grains with very little effort. A ball mill attrition test is used to provide a ranking of the friability from 0-100, very tough to very friable.