Compact air quality meter for detecting the concentration of carbon monoxide (CO), carbon dioxide (CO2), formaldehyde (HCHO) and volatile organic compounds (TVOC). Suitable for indoors (e.g. living room, bedroom, children's room) and outdoors. To assess the ambient air, the detected values are converted to the air quality index (AQI) and displayed. Excessive carbon dioxide levels can cause concentration problems, headaches and fatigue: the air quality meter warns you when levels are too high and reminds you to ventilate vigorously. Values can be easily read off via large displays. The rechargeable battery allows the device to operate for up to 4 hours without power. System requirements: An external USB power supply is required for charging or operation. Not included in the scope of delivery. Consumer Notice:. CO2 concentration can be used to draw conclusions about aerosols present in the air. Increased concentrations of CO, HCHO and TVOC can indicate evaporation from furniture, wood paneling, etc.. We recommend regular butt ventilation in both cases.... Disclaimer:. The meter must not be used as a warning indicator for dangerously high concentrations (e.g. occupational health and safety monitoring). It is not suitable for medical facilities, certification or test measurements. Primarily, the measuring device serves for testing purposes and as orientation in private use. No liability is accepted for possible damage in the event of malfunction. It is not possible to transfer data via the USB cable.