The digital Wtrans E01 measures humidity, temperature and CO2 content and is designed for demanding applications in the field of room monitoring. An alphanumeric display alternately shows all measured values. The high-frequency circuit then sends all the data to the receiver, which is up to 600 m away, by radio. Relay contacts, analog outputs and a digital Modbus interface for reading out up to four Wtrans E01 transmitters are available for further processing. Thanks to the NDIR dual-beam method, the CO2 sensor is maintenance-free and particularly insensitive to contamination. The CO2 measurement works according to the infrared principle (NDIR). A patented auto-calibration process compensates for ageing effects. The air to be monitored is fed to the measuring cell in the housing by convection via the measuring head and a short tube. Gas exchange with the measuring cell takes place via a membrane by diffusion. This prevents contamination of the optical measuring section and the associated inaccuracies. Three variants from 0 to 2000/5000/10,000 ppm are available as CO2 measuring ranges.