M10 - for PM2.5 TVOC HCHO AQI

's suggested to place the device in a ventilated environment for 6 hours before first-time use to get a cleaning cycle for sensors. the procedure, please turn off the device. HCHO(formaldehyde) is suggested to calibrate the detector manually after three months of use as follows. on the detector and wait for 10 minutes. a pin to push the hidden button at the back of the device until HCHO(formaldehyde) icon flashes on the screen. the detector outdoors for ventilation purposes for 10 minutes. calibration is done when the HCHO icon stops flashing.