YESair is a sophisticated, multi-sensor air quality monitoring and information recording instrument that simultaneously measures and records temperature, relative humidity and Carbon Dioxide levels in the air. It also measures and records the levels of four more gases with specific plug-and-play sensors installed. The YESair offers the largest selection and widest range of sensors available on the market. The LCD display indicates all installed sensor types and measured values for each gas as well as battery status and other information. All seven sensors are installed internally and an air sample from the target environment is delivered to them through active sampling by the internal sample pump. The instrument will operate continuously from the supplied wall adapter/battery charger. The user can also set one alarm level for each gas to activate the internal audible alarm.