* Available as uniform polymer spheres in a range of discrete sizes from 20 to 900 nanometers (nm)
* Spherical diameters calibrated with linear dimensions transferred from NIST
* Spheres are used instead of irregularly shaped particles to minimize response of analytical systems to shape effects
* Standards packaged as aqueous suspensions in 15mL dropper-tipped bottles
* Concentrations optimized for ease of dispersion and colloidal stability
* Spheres have a density of 1.05 g/cm3 and an index of refraction of 1.59 @ 589nm (25°C)

Nominal Diameter: 20 nm
Certified Mean Diameter: 21 nm ± 1.5 nm
Std. Dev. & C.V.: not determined
Solids Content: 1%