The EE872 Modular 4 in 1 Probe incorporates the E+E dual wavelength NDIR CO2 sensor, which automatically compensates for aging effects, is highly insensitive to pollution, and ensures excellent long-term stability. The multi-point CO2 and temperature adjustment lead to outstanding measurement accuracy. The RH sensing element with E+E proprietary coating is suitable even for aggressive and corrosive environments. Besides CO2, the EE872 also measures relative humidity (RH), temperature, and ambient pressure (p). Additionally, the devices calculate dew point temperature (Td). The heated versions of the EE872 are suitable even for high humidity and condensing environments. The IP65 enclosure and the PTFE filter cap offer excellent protection in polluted environments. With a catalytic filter cap, the EE872 is appropriate for applications with periodical H2O2 sterilization. The CO2 measured data is available simultaneously on the analog voltage and current outputs. Depending on the EE872 version, the RS485 interface with Modbus RTU protocol also offers the RH, T, p, or Td data. The free EE-PCS Product Configuration Software, together with an optional adapter cable, facilitates the configuration and adjustment of the EE872.