Product Function illustrate: 1.HCHO TestingEquipped with the principle of semiconductor gas sensor.Turn on for 30S to test, the range is0~9.999mg/m3,and the accuracy is 0.001mg/m3.2.CO2 TestingEquipped with non-dispersive infrared (NDIR) principle.Turn on the device for to test,the range is 400~5000ppm,and the accuracy is 1ppm.PM2.5 TestingEquipped with Mie scattering principle can detect the dust particles in the air. Turn on the device for to test.The range is 0~1000ug/m', and the accuracy is lug/m3.TVOC DetectionEquipped with the principle of semiconductor gas sensor.Turn on for 120S to test, the range is 0~9.999mg/m',and the accuracy is 0.001 mg/m'.Testing Result IllustrationThe results showed: super high concentration,high concentration, slightly high concentration,good and excellent.Operation Instructions1.On/OffWhen the power is more than 10%, long press the side button to turn on or turn off.2.CalibrationPlace the device in a ventilated place indoors and outdoors,click on the"About" interface, click the "Calibrate" button,and the device will beep immediately after the calibration.After 10S, the device calibration is finished.3.Air TestingAir testing can be performed after turn on 5 minutes.4.Touch Screen InstructionsSwipe left and right to switch between different interface displays, and tap the corresponding item to enter the corresponding interface setting and switching.Color: white+blackmaterial: plasticPackage Contents:1 x Air Quality Monitor1 x Charging cableOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.