Monitor indoor air data at any time: This indoor air quality sensor helps you monitor the carbon dioxide level in your room so that you can avoid headaches, fatigue and lack of concentration that can result from prolonged exposure to high carbon dioxide levels, and take appropriate measures to ensure air circulation. Multifunction air quality monitor: With its high-precision semiconductor sensor, it can measure the three parameters of carbon dioxide, formaldehyde and TVOC in the room air and simultaneously display the current air temperature and humidity, so that you can understand the air data in real time. Automatic alarm system: When the CO2 concentration exceeds 1500ppm, the digital CO2 meter TVOC HCHO monitor for measuring indoor air quality will sound an alarm to remind you to ventilate the indoor environment in time. This is your practical health assistant. Accurate detection: The high-performance analysis chip is used to accurately detect the weak current generated in the electrochemical reaction process of the CO2 detector, thus providing more accurate detection. During this process, place the detector in a well-ventilated area. The user interface is simple and intuitive, allowing you to start with just one button press, view all test data and turn the sound on and off without having to go through complicated setup or calibration steps. Long standby time: Portable CO2 monitoring meter. Built-in 1200 mA lithium battery, rechargeable, and the standby time is about 240 to 360 minutes; the standby time is ten hours. Compact and portable built-in lithium battery, which can be used directly by connecting the USB cable.