Review on SEAAN Formaldehyde Portable Detector: Advanced Recording Technology for Chemical Safety by Ken Coste

I'm not sure about the accuracy. But I will say that it seems to show correspondingly high levels of carbon dioxide in a small unventilated space and low levels in a well ventilated space. Increased concentrations of particles from candlelight or cigarette smoke are also appropriate. Those are the only measurements I need it for. This device is easy to use and charge, and its price is lower than most sensors. I have no faith in other sensors that are available at a similar price.