US Long-Term Ecological Research Network
Code Definition
A :

Data logger off

A? :

Data logger off an indeterminate number of hours

An :

Data logger off n hours; daily averages may be in error

B :

Data logger off

C :

Sensor off; missing value reported

D :

Sensor malfunction produced bad values; values set to missing;

E :

Sensor noisy; values of uncertain quality

F :

Sensor calibration error; correction factors h