New literature available from Brookhaven Instruments UK gives revised details of three of the most popular ranges of Nist-traceable particle size standards from Duke Scientific
The 3000 Series Nanosphere range of highly uniform polymer microspheres comprises 27 different standards with nominal mean diameters from 20nm up to 900nm while the 4000 Series Microsphere Size Standards continue the progression with 40 more standards with mean diameters from 1um up to 1000um.
All are supplied with certificate of analysis stating mean size, uncertainty and distribution width (coefficient of variation about the mean diameter).
The density of these polymer particles is 1.05g/cm3.
Glass microspheres with narrow size distribution and Nist traceable mean diameters are available in the 9000 Series Certified Particle Size Standards range.
Borosilicate glass microspheres are available in six different mean sizes ranging from 2um to 20um.
Another 24 sizes, from 30um to 2000um mean diameter, are now available made from soda lime glass.
Particle density is 2.5g/cm3 for the borosilicate standards and 2.4-2.5g/cm3 in the case of soda lime glass standards.
A third range of certified standards with very narrow size distribution is the 8000 Series of silica microspheres.
These come in four mean sizes from 0.5um to 1.6um and have a density of 1.8-2.2g/cm3.
All the particles are spherical which minimises shape effects in instrument response and makes them valuable as a source of third party traceability of calibration procedures to national and international standards for the widest possible range of analytical instruments.
