E01

CO2 sensor is out of order

Turn off meter and re-start again

E33

CO2 sensor is out of order

Retry CO2 calibration

E02

Measured value is under range

Put meter in normal condition

E03

Measured value is over range

Put meter in normal condition

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

E60~E65

USB download error

Suggest to format USB stick or try a new type of memory stick.