The south coast AQMD has a great website testing various air quality (mostly pm2.5) in lab and real-world situations against equipment http://www.aqmd.gov/aq-s

The south coast AQMD has a great website testing various air quality (mostly pm2.5) in lab and real-world situations against equipment http://www.aqmd.gov/aq-spec http://www.aqmd.gov/aq-spec