Bringing together fibre-optic
technology and Brookhaven’s expertise in
quasi-elastic light scattering (or dynamic light
scattering), FOQELS offers a practical approach
to studying particle size and particle dynamics
in concentrated suspensions.
Overcoming the problems inherent
in single fibre devices, the non-invasive dual
fibre design of the patented FOQELS probe collects
back-scattered light from within the suspension
while itself never coming into contact with the
sample. Thus, remote measurements – which
can be programmed to repeat at timed intervals
– become possible at particle volume fractions
as high as 40%. The standard fibre length is one
metre but other lengths can be supplied if required.
The scattered light is analysed
using Brookhaven’s BI-9000AT
Digital Correlator and dynamic light scattering
software to yield particle size distributions
at low to medium concentrations where particle
exhibit free Brownian diffusion. At higher concentrations
still, when inter-particle interactions affect
diffusion and assumptions used in the calculation
of particle size are no longer valid, the data
provide valuable insight into particle dynamics
and behaviour under these conditions.
For samples analysed in a standard cuvette, the
sample holder also controls the temperature in
the range 40 to 70C. The optional high temperature
sample holder covers the range from ambient to
1500C, particularly useful with oil samples, for
example.
FOQELS
Specifications:
Sample Volume Fraction:
0.001% to 40% (approx.) Actual range of
applicability depends on both particle size
and concentration.
Particle Size Range:
0.002 to 2 µm approx.
Sample Type:
Most colloidal sized particles, droplets
or bubbles suspended in any liquid.
Temperature Control:
40C to 700C. Special
Option: Ambient to 1500C.
Dimensions:
Probe length: 1 metre (other lengths available).
Probe termination: 85 mm long, 6mm diameter,
stainless steel.
Control Unit:
Size 85(H) x 210(W) x 230(D) mm. Weight
2 Kg
Power Requirements:
100/115/220/240 VAC 50/60 Hz, 200 Watts.
Data Processing:
Brookhaven BI-9000AT Correlator with Windows
software; PC, colour monitor and printer (please
contact Brookhaven for full and latest specifications)
.
