• Alarm sound: press the "mute button" to operate
• CO2 measuring range: 350ppm-2000ppm
• TVOC measurement range: 0.000 mg/m3-2.000 mg/m3
• HCHO measurement range: 0.000 mg/m3-1.000 mg/m3
• Temperature display: Press the "Temperature unit selection key"
• Measurement range: 0-90.0 ℃, 32-194 ℉
• Environmental quality reminder: excellent, the detection value is lower than the set value; good, the CO2 detection value is 50ppm higher than the set value
• TVOC detection 0.01 mg/m3 above setting
• HCHO detection value is 0.03 mg/m3 above the set value
• Pollution: Fast buzzer alarm
• The CO2 detection value is 100ppm higher than the set value
• TVOC detection value is 0.02mg/m3 higher than the set value
• HCHO detection value is 0.06 mg/m3 higher than the set value value value
• When the battery is low, the battery compartment will flash to remind the user to recharge
• When charging, the characters in the battery box will flash sequentially until the battery symbol is fully displayed, i.e. the battery is fully charged 
• Humidity measurement range: 0~99.0RH
• Digital temperature and humidity sensor. LCD display
• Mute key: Turns the alarm sound on or off. In mute mode, the symbol is not displayed and there is no alarm sound. The default is to turn on the sound
• "+" key: to increase the value when setting the alarm value
• Power key: Long press for 2 seconds to switch the power on or off, the digital field counts down from 120 when the power is switched on
• Temperature unit selection key: Celsius and Fahrenheit conversion
• "-" key: alarm value when setting, decrease the value
• Setting key: short press this key to set the "CO2→TVOC→HCHO" alarm value in turn, the original factory setting value is displayed and flashing, parameters are adjusted by the "+" key and "Adjust"-" button and the value is displayed after 10 seconds. Automatic storage
• Power supply: DC5V built-in 1800mAh lithium battery
• Dimensions: 195x95x35mm

Important Notes:

• Before use, please read the following carefully detailed description and use the instrument correctly according to the instructions
• Do not disassemble the instrument or put it into a fire
• Avoid operating the instrument in strong wind conditions
• Avoid shocks and drops
• If the instrument is not used for a long time, the warm-up time will be long
• Do not allow liquids to flow into the instrument
• After the test, the power of the equipment must be turned off to avoid accidents
• Prevent the instrument from vibrating violently
• If the instrument is left for a long time, odorous gas will accumulate inside the instrument, which will seriously affect the test results, in this case, the instrument must be placed in a cool and ventilated place and then used for more than 1 hour (the instrument does not need to be operated during the ventilation process)
• Expired and defective products should be handled and repaired in time
• Avoid impacting the sensor with gases above the measuring range, as this may damage the sensor, and man-made damage is not covered by the warranty Introduction to the instrument