• These microspheres show a size distribution which is appropriate for methods that need particle size uniformity between monodisperse (highly uniform, <5% CV**) and polydisperse (widely distributed, <12% CV). These include instruments for light blockage, light diffraction, acoustical imaging, electrolyte displacement or other methods used for analysing wide size range materials. The material is composed of polystyrene cross-linked with divinylbenzene. This gives the particle good durability and chemical stability. They can be washed in water-alcohol mixtures and resuspended in water, air or similar media. The density of polystyrene is 1.05 g/cm3, and the index of refraction is 1.59 at 589nm (25C). Microspheres in this series are packaged as an aqueous suspension in 15 mL dropper-tipped vials.
  • 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.
  • Small borosilicate glass microspheres have fewer spherical imperfections and inclusions than other glass microspheres. They also have better mechanical and thermal stability. This series has been calibrated with NIST traceable methods of optical microscopy. They are packaged as dry powders in 1 gram bottles. They have a density of 2.50-2.55g/cm 3 and an index of refraction of 1.56 @ 589nm (23°C). Brands: Thermo Scientific
  • Thermo Scientific provides these products for calibrating particle counters which require dry particles, from 5 to 100 µm. They are conveniently packaged in dropper-tipped vials in 1 gram quantities, enabling the user to dispense the microspheres directly into the sampling chamber. They are not suitable for dispersion in liquid media. The mean diameters are traceable to the National Institute of Standards and Technology (NIST). DRI-CAL™ Particle Size Standards are composed of polystyrene DVB (divinylbenzene) and have a density of 1.05g/cm3. The refractive index is 1.59 @ 589nm. The certified mean diameter was determined by optical microscopy using a NIST calibrated stage micrometer. Size distribution was determined by electrical resistance analysis.
Go to Top