• This series of NIST traceable size standards provides an accurate and convenient method for calibrating or checking the performance of laser particle counters used in cleanrooms and other contamination monitoring applications. The products are suspensions of monodisperse polystyrene spheres (PSL) for use in airborne or liquid particle dispersion systems. They are available in a range of sizes from 0.1 to 100µm in diameter. The particles are prepared as low residue aqueous suspensions for minimal background interference, packaged in 15mL dropper-tipped vials. The particle diameters are calibrated by electron or optical microscopy. Each package includes a Certificate of Calibration and Traceability to the National Institute of Standards and Technology (NIST). In comparison with the well established 3000 and 4000 Series products described elsewhere, these product lines are precisely diluted for immediate use in laser particle counters with minimal time-consuming adjustments of concentration.
  • These uniform microspheres are NIST-traceable by calibration methods such as optical microscopy. Products from 1 to 160µm in diameter are packaged as aqueous suspensions of polystyrene spheres in dropper-tipped bottles. Diameters of 200µm and larger are packaged as dry spheres in screw-capped bottles. These larger particles are composed of polystyrene DVB (divinylbenzene). The spheres have a density of 1.05g/cm3 and an index of refraction of 1.59 @ 589nm.
  • These products are designed for applications requiring monodisperse inorganic spheres. Like glass, silica has a much higher density than polystyrene and the opaque spheres provide more contrast than polymer particles in optical and electron beams. They are calibrated by NIST traceable methods developed by Thermo Scientific, and are suitable for a wide variety of particle measurement applications. They are packaged as aqueous suspensions in 15ml dropper-tipped bottles at a concentration of 2% solids. The silica spheres have a density of 1.8-2.2g/cm3 and an index of refraction of 1.40-1.46 @ 589nm (23°C).
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