The product adopts the principle of scattering, can monitor air quality, temperature, humidity and aqi grade. it has 999 groups of data records, can view the data curve, with 3.2-inch tft full-color display, automatic measurement, real-time date and time, rechargeable lithium battery or separate external usb power supply, stable data, etc. Features: Air quality monitor: there are 2 models for option. tc-8100 features 3 channels to detect the number of 0.3um, 2.5um particle size dust, the concentration of pm2.5 and pm10, aqi grade, temperature and humidity. tc-8200 features 6 channels to detect the number of 0.3um, 0.5um, 1.0um, 2.5um, 5.0um, 10um particle size dust, the concentration of pm2.5 and pm10, and it can detect the class of class 100 clean room and below clean room, temperature, humidity and aqi grade. 3.2" tft color screen & comfortable buttons: large color screen with backlight can enhance reading experience, and the brightness can be easily adjusted. it also display real-time date and time. / switchable. auto shutdown to save battery, more power-saving. with comfortable operating buttons, easy to use. Data record, curve graph & pm2.5 alarm: it has 999 groups of data records, and you can view the data curve conveniently by pressing the graph button once. with pm2.5 alarm function, turn on/ off alarm buzzer and set the alarm value easily. Dual power supply: rechargeable lithium battery or usb cable powered. built in 2000mah lithium battery, has about 9 hours long working time, easy to be charged via usb interface. and the battery cover is easy to be removed and installed, making it convenient to replace lithium battery. Tripod support & wide application: comes with a tripod for supporting, more convenient to use. applied to clean room inspection; industrial production of electronics, optics, chemicals, food, medicine and health, biological products, aerospace, etc.; filter seal inspection; particle pollution source detection. Specifications: Color: grey & yellow/ grey & red (optional) Model: tc-8100 (grey & yellow)/ tc-8200 (grey & red) Material: abs Concentration resolution: 1g/m³ Flow: 1 liter/min (2.83l=1l*2.83) Response time: about 1s Boot stabilization time: about 10s Temperature measurement: -10~60 range, ±2 accuracy, 0.01 resolution Humidity measurement: 0~100% range, ±3% accuracy; 0.01% resolution Built-in battery: 3.7v 2000mah lithium battery Charging voltage: 5v/ usb Item size: 222 * 80 * 46mm / 8.74 * 3.15 * 1.81in Item weight: 311g / 10.98oz Package size: 26 * 21 * 8cm / 10.24 * 8.27 * 3.15in Package weight: 738g / 1.63lbs --tc-8100 3-channel particle size: 0.3m, 2.5m, 10m Pm2.5 range: 0~1000g/m³ Pm2.5 precision: ±12g/m³ --tc-8200 6-channel particle size: 0.3m, 0.5m, 1.0m, 2.5m, 5.0m, 10m Pm2.5 range: 0~1000g/m³ Pm2.5 precision: ±10g/m³ (0~100g/m³), ±10% (100~1000g/m³) Number of particles output range: ≤2,000,000 granule/l Cleanliness standard: meets the iso 14644-1 iso5 level-iso9 level Package list: 1 * dust particle counter 1 * usb cable 1 * tripod 1 * user manual (english)