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 features an automatic scrolling function. There are alarm setting options for the CO2 level as well as for maximum and minimum values of temperature and humidity. Power is supplied via 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 can reduce concentration and performance. To improve the indoor climate and maintain health, regular and timely ventilation is recommended. The WL1030 provides accurate measurements based on a powerful NDIR gas sensor with CO2 measurement and an additional calibration function. The Technoline WL 1030 is suitable for private, commercial, and public spaces and supports a healthy indoor climate and the maintenance of health with timely ventilation recommendations. The CO2 content in the indoor air is displayed through accurate ppm values and is accompanied by ventilation recommendations with colored indicators in a traffic light system.