Air quality sensor and CO2 measuring device for monitoring indoor air quality. The measurement is based on the CO2 content in the air. It displays the indoor temperature and humidity. The MIN/MAX value storage for the last 24 hours comes with an automatic scrolling function. There are alarm setting options for CO2 levels as well as for maximum and minimum values of temperature and humidity. The power supply is provided by an external 5 V 1.2 A power adapter. The wall or table CO2 display is a device that simultaneously measures and records CO2, humidity, and temperature. High CO2 levels in the air reduce concentration and performance. To improve the indoor climate and maintain health, regular and timely ventilation is recommended. The WL1030 offers accurate measurements based on a powerful NDIR gas sensor with CO2 measurement and an additional calibration function. The Technoline WL 1030 is equally suitable for private, commercial, and public spaces and supports a healthy indoor climate and health maintenance with timely ventilation recommendations. The CO2 content in the indoor air is displayed through precise ppm values and supplemented with ventilation recommendations using colored indicators in a traffic light system.