E01

The CO2 sensor is not working

Switch the instrument off and back on again

E33

The CO2 sensor is not working

Repeat the CO2 calibration

E02

The measured value is too low

Place the device in a normal environment

E03

The measured value is too high

Place the device in a normal environment

E11

RH calibration error

Repeat the humidity calibration

E31

Temperature sensor or AD damaged

Send the instrument in for repair

E32

Memory IC damaged

Send the instrument in for repair

E33

RH sensor or circuit damaged

Send the instrument in for repair