EC-5 User’s Manual
4. Collecting Data
13
7. Under the “Sensors” file tree, double-click on
“Meteorological” and then select “Soil Moisture.”
8. Choose “EC-5” Sensor.
Calibration
Decagon’s ECH
2
O Utility, and DataTrac3 automatically
apply factory calibrations to the sensors’ output data.
However, this general calibration may not be applicable
for all soil types. For added accuracy we encourage our
customers to perform soil-specific calibrations.
The calibration equation that you will use depends on
where you will be using it. If you will be using it with
sensors connected to a non-Decagon data logger you
will need to use the 2500 mV calibration. If you use any
Decagon software (DataTrac3, ECH
2
O Utility, etc.) or
the user calibration menu in the ProCheck, you will
need to use the RAW calibration. The difference
between the two is the slope constant. To increase the
resolution of the sensor output, Decagon uses all avail-
able increments of the 12-bit number (value of 4096)
where the measurement is stored. Thus, the output of the
sensors read by the ProCheck and Decagon loggers
must be multiplied by 0.61 AND the 2500 mV slope to
give the right value.
Sensor Calibration Values
Following is a list of the both the millivolt and RAW
calibration values for the EC-5, where
is the volumet-
ric water content, mV is the millivolt output of the sen-
sor, and where
x
is the RAW sensor output.
