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3
O
VERVIEW
The Field DataLogger Mini (FDL Mini) is a digital microsensor amplifier with datalogger
capability. It can operate as an autonomous unit that measures and logs data as specified by
the user before deployment. After deployment data may be downloaded to a Windows PC
using the SensorTrace Logger software. Alternatively, it can be operated from a Windows PC
using the SensorTrace Logger software displaying and logging data in real time.
The FDL Mini comes with 2 or 4 sensor channels. Each channel may, at the time of purchase,
be configured as either amperometric (O
2
, N
2
O, H
2
S, NO, H
2
) or potentiometric (pH, redox).
Furthermore, two different sensor mounting options may be chosen (at the time of
purchase):
a: The sensor is mounted directly on the housing and the amplifier is built into the unit
b: The sensor is mounted on an in-situ amplifier with cable connection to the housing
The FDL Mini has built-in support for STOX sensors, on channels with internal amplifier, with
a detection limit of < 10 nM O
2
. The STOX support may be set individually for each channel
and data showing polarization of the front guard is collected together with the signal for O
2
concentration.
The FDL Mini may be integrated with other platforms. It may be powered from a CTD or
ADV or other source using a 6
–
28 V power supply, and store and synchronize the measured
data on a third-party device via the 0
–
5 V analog output from the FDL Mini.
3.1 Operating and setup conditions
The Field DataLogger Mini is built for 6000 m water depth.
Important:
The connectors on the FDL Mini must never be open when the unit is
submerged. Each connector on the unit must either be mounted with the
appropriate cable or sensor or must be covered with the appropriate
protective cap.
Note that the metal screw caps for the sensor connector bulkheads are not
waterproof and can not be used for deployment. In stead 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 (
see the “Unisense in situ
connector” manual
).
Temperature:
-10°C - 60°C
Internal battery: 13 Ah @ 7.4 V, deployment time up to 3 months @ 25°C
External battery: 2 x 13 Ah @ 7.4 V, deployment time: up to 6 months @ 25°C (to be
purchased separately)