Particle Size Standards
Polystyrene latex spheres, polystyrene latex spheres, polystyrene latex particles are particle size standards with NIST traceability and certified calibration referenced to SRM size standards as produced by National Institute of Science and Technology. PSL Spheres and polystyrene latex spheres support size calibration for aerosol particle counters, laser particle counters and are used in aerosol science applications. Particle size standards are also used in the production of calibration wafer standards. PSL Spheres are provided from 20 nm to 160 microns in 15 ml volumes, but can be provided in 100 ml volumes as a special order; while silica particles are provided from 40 nm to 2000 nm.
Silica particles are provided from 40 nm to 2000 nm as particle size standards with NIST traceability and certified calibration referenced to SRM size standards as produced by National Institute of Science and Technology. Silica particles are 10% concentration of solids in liquid, typically offered in 15 ml liquid volumes or 100 ml liquid volume. Silica particles below 105 nm are in solution with ethanol, which helps to minimize particle agglomeration of nanoparticles. Silica particles from 105 nm to 2000 nm are in solution with Deionized water. Special orders can be made for 500 ml or 1 liter volumes of silica particles with the same 10% concentration of solids in the liquid solution.
Particle Size Standards are ordered directly on the Applied Physics links above, or call AP at (719) 428-4042.
Laser particle counters are designed to detect 50 nm particles and larger in the air, and are frequently calibrated using polystyrene latex beads, typically at 100 nm, 1 micron and 10 microns. Laser particle counters typically offer from 1 to 5 size bins, thus the LPC is typically calibrated at 1 to 5 size peaks. Condensation particle counter, CPC, is designed to detect particles above 10 nm, and any size particle can be used to verify CPC particle counter operation. Particle spectrometers typically offer 20 to 40 size bins, and are usually calibrated at 3 points, typically 50 nm, 100 nm and 1 um. In every type of particle counter calibration the size peaks are typically 3% or less in size distribution. And the particle size standards are NIST traceable, thus the calibration points are quite accurate. While PSL spheres are used in aerosol science applications, silica particles are most often used in drug delivery applications and semiconductor metrology applications. Silica particles and PSL Spheres can be ordered by calling Applied Physics at (719) 428-4042.
PSL Spheres are used with PSL Wafer Deposition Systems to produce PSL Wafer Standards, also referred to as Particle Wafer Standards. In either case, after the PSL Wafer Standard is produced, it is then placed on a wafer inspection system and scanned by a single laser SSIS or dual laser SSIS. The actual PSL size response is compared to the SSIS size response. If the two peaks do not match, the SSIS must be calibrated.
Pre-mixed, high concentration PSL Spheres are for 2300XP1 systems, 2300 NPT-1 systems, 2300NPT-2 and M2300G3 wafer deposition systems.
Un-mixed PSL Spheres, generally in 1% concentration.
The pre-mixed PSL Spheres come in a 50ml bottle, mono-disperse in size (1 size distribution), and are provided from about 47nm to 950nm in size. This PSL solution is poured directly into the nebulizer or atomizer vessel. Pre-mixed is a convenient way of purchasing the polystyrene latex beads, since all the dilution has been accomplished in a very uniform manner, no muss, no fuss, permitting the user to not deal with mixing the polystyrene latex beads using beakers, DI water and ultrasonic trays. The un-mixed PSL material is provided in a 15ml bottle, mono-disperse in size (1 size distribution), and usually in a 1% concentration. These PSL Spheres are provided in a broad range of sizes, but for our purposes, from 20nm to 4um in size. The PSL material must be mixed to the proper dilution or it will be to concentrated or too weak to provide effective results when trying to deposit by one of the above PSL Wafer Deposition Systems.