8
OpERATION
determined from time series data such as those presented in
. A wetness threshold
should be chosen that is slightly above the dry output, and subsequent readings should be
compared to the dry output to determine surface wetness. When using a non-METER data
logger, it is important to collect data frequently enough to capture changes in the surface
wetness. A sampling frequency of 15 min or less is often necessary to accurately capture leaf
wetness duration.