Air Quality Monitor,DAMPOT Formaldehyde Detector, Pollution Meter, Sensor, Tester; Detect & Test Indoor Pollution, TVOC Volatile Organic Compound Gas, PM2.5 2.5 Micron Particulate Matter Dust

Any Chinese speakers out there who can help before I return this? Can only rate it 1 star so far . It's been 'initializing' all afternoon and gets no further! A reset button might help.

Looks like it works well, except for temperature and humidity. Sprayed a tiny bit of aerosol deodorant in the bathroom, and the TVOC went off the scale to 9.999mg/m^3. Will just use roll-on now. Not sure about absolute calibration, but since for use round the house I can try little experiments to see how the readings change. e.g.