General description The CO2 Sensor Thermometer Hygrometer is a portable real-time air quality tester designed to monitor carbon dioxide concentration, humidity, and ambient air temperature. Featuring a high precision NDIR infrared sensor, this multifunctional device measures air quality levels ranging from 400 to 5000 ppm. Its lightweight and elegant design makes it easy to carry and suitable for various environments such as patios, bars, offices, cars, and schools. Technical specifications Measurement range: 400-5000 ppm Sensor type: NDIR infrared sensor Built-in rechargeable battery Usage The CO2 Sensor features an intuitive design with a color-coded display indicating air quality levels: red for poor air quality, yellow for normal levels, and green for good quality. It includes a built-in alarm that activates automatically at the 1000 ppm level, with an option to turn off the alarm sound by pressing the power button. An indicator light on the screen shows when the alarm is