NIST SRM particle size standards are the calibration standards known around the world for use with any application that requires a NIST SRM (size reference material) size standard with extremely accurate sizing, narrow size peaks and narrow standard deviation. They can be used for the calibration and validation of a variety of particle sizing equipment including light scattering instruments, electron microscopes, and differential mobility analyzers. They are particularly critical for calibrating surface scanning inspection systems, which are used to detect and characterize defects on silicon wafers. Accurate reference particles are needed to develop and advance the scanning systems for high throughput, cost-effective wafer production that is crucial for device miniaturization. The reference particles may also be used for supplying mono-disperse (single size peak) particles for testing aerosol instruments and are useful for examining aerosol kinetics and evaluating particle detector response.
The certified value for the modal diameter:
60 nm SRM 1964 polystyrene spheres is 60.39 nm, with an expanded uncertainty of ± 0.63 nm;
100 nm SRM 1963A polystyrene spheres is 101.8 nm, with an expanded uncertainty of ± 1.1 nm;
269 nm SRM 1691 polystyrene spheres is 269 nm, with an expanded uncertainty of ± 4 nm;
895 nm SRM 1690 polystyrene spheres is 895 nm, with an expanded uncertainty of ± 5 nm.
Measurements were performed using differential mobility analysis and are traceable to the He-Ne laser wavelength in air, 632.807 nm, which has been determined with respect to the fundamental standard for length.
PSL Spheres, 20-900nm, Polystyrene Latex particles – Buy Now
PSL Spheres, 1um-160um, Polystyrene Latex particles – Buy Now
The spherical diameters are calibrated with linear dimensions calculated by NIST. Spheres are used instead of irregularly shaped particles to minimize the response of laser scanners which are sensitive to shaped particles. The standards are packaged as aqueous suspensions in 5 milliliter (mL) dropper-tipped bottles. The particle concentrations are optimized for ease of dispersion and colloidal stability. The spheres have a density of 1.05 g/cm3 and an index of refraction of 1.59 @ 589 nm, measured at 25 degrees centigrade.
Each package contains a Certificate of Calibration and Traceability to NIST which includes a description of the calibration method and its uncertainty, and a table of chemical and physical properties. A Material Safety Data Sheet, with handling and disposal instructions, is also available. PSL bottles are lot-numbered for convenient technical service and support after the sale.