How accurate are common particle counters?

When I started Smart Air in 2013, I wanted to buy an air quality monitor. I had basically two options. I could buy a US$260 Dylos or spend thousands of dollars on the crazy expensive particle counters. Since then, the market has exploded with new air quality monitorsĀ as cheap as 99 RMB. But are they … Continue reading How accurate are common particle counters?