Indoor Air Quality (IAQ) monitors have come a long way in the past few years. Air pollution sensors used to cost several hundred dollars and was used only by researchers, but as with any technology, such sensors have become cheaper and smaller which have led to a whole slew of compact monitors geared towards consumers who can purchase to monitor their own home air quality. Keep in mind, many portable air filter units now have such sensors built-in. These monitors have become useful for patie…