Products

Particle Size Analyzers

FOQELS

Fiber Optic Quasi Elastic Light Scattering
Particle Sizing in Concentrates by Dynamic Light Scattering

  • Overview
  • Typical Applications
  • Specifications
  • Options & Accessories

Features at a glance

  • Particle sizing in concentrates, no dilution!
  • Fast, compact and easy to use.
  • New!! High temperature capability.
  • Remote measurem. possible, timed sequences.
  • Built in automatic procedures and parameters.
  • No contamination of sample or probe
  • Hostile environment capability
  • Complete with computer and color printer.
  • Customizable reports.
  • Available as an accessory to existing systems.

A special Instrument

At last, a simple, practical approach to automatic particle size analysis of concentrated suspensions. Brookhaven Instruments brings together the fiber-optic (FO) detection and quasi-elastic light-scattering (QELS) technologies to create the innovative FOQELS particle size analyzer. The Brookhaven FOQELS particle size analyzer allows measurements to be made over a much greater range of concentrations than than standard Dynamic Light Scattering (DLS) instruments.

The unique, state-of-the-art, optical microfiber probe (US Pat. No. 5,155,549) provides the key technology for a compact and inexpensive instrument to measure in suspensions concentrated up to 40% by weight.

Our new high-temperature sample cell holder provides controlled temperatures from ambient up to 160 °C. This device uses a space-age insulation material and is ideal for applications such as high-temperature oils.

Operation

Two fibers are housed in a single stainless steel probe. In use the probe is positioned to view the sample either through the wall of a cuvette or through a window. The illustration below shows details of the construction of the probe. Note that the probe does not touch the cuvette wall and that the sample never touches the probe.

Principle of Operation: Visible light from a laser diode is launched into the sample via a monomode fiber and the scattered light is collected by a second monomode fiber at an angle of 153°. The scattered light is analyzed using the established techniques of Dynamic Light Scattering (DLS) with our TurboCorr digital autocorrelator. The troublesome homodyne signals that arise in single fiber optic designs are eliminated. The FOQELS yields accurate and reliable results because it operates in a well controlled self beating mode.


Typical Applications

  • Particle sizing in situ!, and in real time!
  • Micro-emulsion technology
  • Stratification and hydrodynamic instabilities
  • New!! High temperature capability for oils and similar
  • Emulsion polymerization, particle size growth
  • Metallic oxide manufacture
  • Nucleation processes
  • Medical and biological systems
  • Protein crystal growth
  • Cataractogenesis in human eye lenses

Specifications

Suspension Concentration 0.001% to 40% (approximately), actual range of applicability depends on both particle size and concentration
Size Range 0.002 to 2 microns
Sample Type Most colloidal sized materials suspended in any liquid
Temperature Control 4 °C to 70 °C, or ambient to 160 °C using the high temperature cell holder option (see below)
Dimensions
  • Probe length: 1 meter standard (other lengths available)
  • Probe termination: 85 mm long, 6 mm diameter, stainless steel
  • Control unit: 85 x 210 x 230 mm (HWD)
Weight 2 kgs
Power Requirements 100/115/220/240 VAC 50/60 Hz, 200 Watts
Computing Requires link to a Windows™ PC which carries a TurboCorr digital autocorrelator; such computers can be supplied by Brookhaven with the instrument
Certifications CE Marked

 

A policy of continual improvement may lead to specification changes.

Options and Accessories

BI-FHTC: This high-temperature sample cell holder provides controlled temperatures from ambient up to 160° C. It uses a space-age insulation material and is ideal for applications such as high-temperature oils.