Review on Accurate VIVOSUN Pollution Detector: Formaldehyde & Humidity Measured with Precision by Brian Rivenbark

We bought a few different air monitors because most of them seemed to have trouble with a specific reading (e.g. HCHO, TVOC, CO2, Temp Humidity etc); This was initially our first choice due to settings and data transfer/tracking functionality, but after a few hours both HCHO and TVOC went to 0 and stayed at 0. All of our other monitors said otherwise. (Also, 0 is generally impossible in our environment). Another small issue is that the fan is very noisy. If you put it next to you in a quiet room, the hum can be more distracting than you might expect.