idronaut Ocean Seven 304Plus, Operator'S Manual

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APPENDIX B – CONDUCTIVITY WITH INTEGRATED UV-LED ANTIFOULING
IDRONAUT – Brugherio (MB) OCEAN SEVEN 304 Plus CTD 12-2015
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B.1 INTRODUCTION
A UV-LED (Ultraviolet 250 ÷ 300 nm @ 500 µW, Light-Emitting Diode) is integrated into the
conductivity sensor quartz cell (patent pending). The UV-LED sterilizes the early growth of
biofouling, thus eliminating environmental drift in the conductivity sensor.
This innovative solution does not break the European rules, which do not permit the use of Tributyltin
(TBT), a very toxic and poisoning (carcinogenic) substance which has been banned by the
international government agencies, mandatory to protect any recessed conductivity cell, which
present a very small diameter and may get contaminated or even clogged.
The UV-LED is excited, for a configurable amount of seconds, when the CTD wakes up and during
the time spent during the measurements, according to the following rules.
The UV-LED sterilization is automatically switched off at the end of the sterilization time-out if:

the CTD is interrogated through the operating menus or the communication protocol functions;

the CTD enters stand-by mode;

the CTD carries out a measurement cycle in function of pressure interval, real-time acquisitions or
continuous acquisitions;

the CTD carries out an autonomous cycle: LINEAR, CONTINUOUS, CONDITIONAL.
B.2 SET-UP OF THE UV-LED ANTIFOULING STERILIZATION TIME
Through the CTD set-up, it is possible to configure the UV-LED antifouling sterilization time in
seconds. This time is spent by the probe during the wake-up to sterilize the conductivity sensor. The
sterilization continues (as it does not affect the conductivity measurements) until the CTD switches off
by itself and configures the next data acquisition time according to the above rules.
Configuration of the UV-LED sterilization time-out in seconds is done by modifying the conductivity
sensor configuration:
OCEAN SEVEN 304Plus
Id Name Code Mux Digits
01 Press 0000 253 0002
02 Temp 0001 253 0003
03 Cond 0002 254 0003
04 Sal 0004 255 0003
CMD:I)nitialize,M)odify,D)elete,Q)uit
At the end of the list, commands available to perform the configuration are shown below:
Initialize: completely deletes the list.
Modify: allows the operator to enter a new sensor/parameter in the list or modify an existing
one. See below for the details about configuration.
Delete: allows the operator to delete a configured sensor/parameter from the list.
Quit: terminates the parameter editing and ends the configuration command too. The new
configuration is stored in a non-volatile memory.
The following para
meters can be configured by means of the “Modify” command by selecting the
CONDUCTIVITY sensor from the above list:
Sensor code[0..24,255=NU]< 2
Sensor mux.[0..3,255=NU]< 1
Sensor precision [0..6]< 3
UV disinfection time [0.255]< 5