In particle physics, an elementary particle is one that is not made up of smaller particles, and is also known as a fundamental particle.
Regular Websites
BPA Air Quality Solutions: Particle Counters
A particle counter is a sophisticated monitoring device that counts the amount of particulate contamination in the air, on a surface, or in a liquid. The focus of this site is on the sale of particle counters from a variety of manufacturers, but the technology itself is described, along with information about calibration and other topics. - BPA Air Quality Solutions: Particle Counters
http://www.particlecounters.org/
An educational site that explores what our universe is made of. Learn about many types of particles and forces - quarks, leptons, neutrinos, antimatter, extra dimensions, invisible dark matter, strong force, gravity, accelerators and multi-component detectors. Visitors to the site can buy posters, CD-ROMs, physics book and use free worksheets. - The Particle Adventure
http://www.particleadventure.org/