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concentrations. The raw data will be saved in the Logger file and may be exported for
doing manual calibration.
Calculation of calibration concentrations:
•
Air saturated water at 10°C and a salinity of 30 = 291.2 µM
•
3.0 ml air saturated water added to 300 ml water gives an increase in concentration
of: 291.2 x (3/303) = 2.88 µM
Note that it is not necessary to know the O
2
concentration of the N
2
bubbled water. The
∆
-signal for zero O
2
is per definitio
n zero and the ∆
-signal increases linearly with O
2
concentration. Therefore, it is only necessary to estimate the slope of the calibration
curve (µM/mV) i.e. the increase in ∆
-signal for a given increase in O
2
concentration.
See the STOX sensor manual for more details (
http://www.unisense.com/manuals/
7.9 Making a deployment
To make a deployment with the FDL Mini the following is needed:
•
Remove the
Off-dongle.
Wait 30 seconds and connect the instrument to a PC and
start SensorTrace Logger
•
Make sure the FDL Mini has power and storage capacity
o
See
7.3.4 Checking battery level and storage capacity
•
For each channel set the correct polarization voltage for the sensor to be connected
o
See
7.3.1. Setting polarization
•
Set the Sampling rate
o
See
7.3.2. Setting sampling rate
•
Connect the sensors
o
See
7.4 Connecting the sensors
•
Set the appropriate sensor type and unit for each channel
o
See
7.3.5. Setting channel information
•
Let the sensors stabilize
o
See
7.4 Connecting the sensors
for advice regarding minimizing this period
•
Calibrate each sensor
o
See
7.6.1 Calibrating the sensors
•
Remove the PC to FDL Mini cable and place a dummy on the bulkhead connector
•
Make sure all bulkhead connectors on both ends of the pressure housing are either
connected or capped with a dummy.
o
NOTE: The metal screw caps for the sensor connector bulkheads are not
waterproof and cannot be used for deployment. Instead an in situ connector
must be mounted on each sensor connector bulkhead. The in situ connector
may be mounted with a sensor or with a sensor dummy, i.e. a closed glass
tube. The in situ connector must be filled with oil for all deployments
whether mounted with sensor or glass tube.
•
The FDL Mini is now ready for deployment