BI-XDC Particle Size Analyzer

By providing both centrifugal and gravitational sedimentation in one instrument the BI-XDC brings these well established methods of particle sizing up to date for today’s fine particle technology.

High Resolution Particle Size Analysis

By providing both centrifugal and gravitational sedimentation in one instrument, the BI-XDC brings these well established methods of particle sizing up to date with today’s fine particle technology. With an X-ray technology to give error free measurements, fast and accurate size distributions across the “one-micron” transition region are easily obtained. Now, with a single instrument you can get true high resolution, accurate particle size distributions from 10 nanometers right up to 100 microns. Brookhaven’s advanced scanning detector technology and wide disc speed range lets you optimize analysis times and broaden the range of samples you can analyze.

With the Brookhaven BI-XDC there are no optical corrections and no optical properties to worry about, just a simple mass sensitive response based on X-ray absorption.

Typical runs take 3-30 minutes and are dependent upon the particle size range to be determined. Real-time progress of the experiment is plotted on the screen. Standard plots include differential and cumulative distributions of particle sizes weighted by volume, surface area and number on linear and logarithmic scales. Up to six plots can be overlaid for comparisons and additional tabular and other choices of display provide customized reports for a wide variety of purposes including SPC charts. A menu of data files allows easy analysis of multiple experiments.


Features at a glance

  • Accurate and quantitative
  • Resolves mixtures
  • X-ray detection – no optical corrections
  • Range 10 nm to 100 µm
  • Scanning head for high speed
  • Simple operation
  • Clear text and graphical reports

Measurement Principles

Qext is a strong function of the particle size but it is not easy to calculate accurately for high density particles. The key difference is the use of µabs which is the x-ray absorption efficiency instead of Qext. It is not a function of particle size or refractive indices. There is no optical correction. Notice that the decay function includes µabs. At time 0, there is 100% absorption and therefore no signal. As time progresses and absorption declines the signal is generated and produces a cumulative size distribution.

  • It = Io×exp(-µabs×c×L)             Io, It = Transmitted, Incident Intensity
  • µabs = X-ray absorption efficiency ≠ f(dp, np/nf, λ)
  • c = Mass concentration
  • L = Path length (width of fluid segment in disc)

When X-rays are absorbed, they are absorbed in proportion to mass without any dependence on particle size or refractive indices. There is no optical correction. For high density materials with normally high refractive indexes, the mass weighted size distribution is quantitative.

Read our article comparing our two disc centrifigues for more information.

Typical Applications

The versatile BI-XDC offers high resolution results to particle sizing problems where the particles are dispersed in a liquid and cover the size range from 0.01 to 30 microns. This range is useful for a variety of materials and many applications:

  • Abrasives
  • Inorganic pigments
  • Catalysts
  • Metal oxides
  • Cements
  • Metal powders
  • Ceramics
  • Minerals
  • Clays


Size Range 0.01-100 microns, depends on particle and liquid density and liquid viscosity
Centrifuge Speed 500-6000 rpm, +/-0.01%, high speed disc available see options
Disc PMMA construction, 10-30 mL volume, solvent resistant disc available see options
Scanning Speed 0.05-10 mm/min, 1 mm/min typical
Measurement Time 3-30 min, typically 8 min/decade in particle diameter,
Data System High-performance Windows™ system with color printer. Contact factory for latest specifications
Software Written for Windows™, control, archiving and data analysis,
Power Requirements 100/115/240 VAC, 50/60 Hz, 300 Watts,
Dimensions 230(H) x 460(W) x 600(D), mm
Weight 35 kgs
Certifications CE Marked

Options & Accessories

BI-DSCXR: Solvent Resistant Disc for use with many organic solvents.

BI-DSCXH: High speed disc (for use with aqueous dispersions), 10,000 rpm max

Download Brochure

BI-XDC Brochure PDF

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