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IDRONAUT CDT 302 PROBE
 Overview
The Idronaut CDT 302 probe is a 50
mm diameter water quality probe which measures pressure,
temperature, fluid conductivity (dual range), pH,
dissolved oxygen, and oxidation-reduction potential (redox)
Salinity is calculated automatically using temperature,
conductivity, and pressure, using the UNESCO formula.
Different sensor arrangements exists.
The Idronaut probe is modified to
operate on the MGX II digital logger. The modification
includes a new downhole power supply and FSK modem. This
allows the MGX II to power the probe and communicate
with the Idronaut probe. The probe is powered with 50
VDC, and sends data to the surface at 9600 baud, even
parity, 8 data bits, and one stop bit.
The probe comes in various pressure
ratings, ranging from 300 dbar to 1500 dbar.
The CDT 302 Multi-Parameter Probe
has been specifically designed for borehole application
and uses very reliable, accurate and drift free high
quality sensors, associated with advanced and
miniaturised electronics. Integration of geographical
position information, through GPS, and acquired data can
be performed by means of the IDRONAUT probe management
software.
High Performance combined
Temperature and Conductivity Sensors
TEMPERATURE SENSOR
Features a very fast platinum resistance thermometer
(time constant: 50 ms). Negligible self-heating effect.
FLOW CONDUCTIVITY SENSOR
Features a very large diameter, seven-ring quartz cell
which does not require platinum black deposition and
which can be cleaned without re-calibrating.
OXYGEN SENSOR
Features an innovative pressure-compensated
polarographic sensor, with a replaceable cap for
membrane support. Stirring effects are negligible.
pH GLASS SENSOR (7000 m)
Cylindrical, high-pressure glass membrane pH electrode
in conjunction with a special differential amplifier
system.
OXIDATION-REDUCTION POTENTIAL (ORP)
SENSOR
Special cross section platinum electrode.
SOLID GEL REFERENCE ELECTRODE
A reference electrode for pH and oxidation-reduction
potential measurements. It uses a special ceramic
junction-less design. Operation to 7000 m. Long life.
DATA TRANSMISSION
Via MSI Modem.
INTERNAL MEMORY
Provides up to 1,500 data acquisitions each of 8
channels.
DIMENSIONS AND WEIGHT
50 mm diameter x 650 mm length; 2,3 kg in air.
OPTIONAL SENSORS
Calcium, Copper, CO 2, Nitrate, Ammonia and Chloride.
All sensors have extremely low time
constants (50 milliseconds for physical parameters [CTD]
and 3 seconds for chemical parameters). The slim line of
the Probe and the pressure-compensation of sensors
permit operation in fast water profiling or in fixed
depth monitoring down to 1500 metres depth. Scanning of
the sensors takes place at a rate of 25 milliseconds.
The user can decide to perform spot measurements or to
acquire data which are the average of a certain number
of sensor scans; said number is selectable through the
Probe software. The electronic boards are fitted in an
AISI 316 stainless steel sealed housing; one
oceanographic connector, located on the top cover,
provides the probe power supply and data exchange with a
suitable external device. On the opposite end, the
sensor area is protected against accidental bumps with
an AISI 316 stainless steel protective cage.
The CDT 302 PROBE is
microprocessor-controlled, and measures and transmits
sensor data through the shielded coaxial cable via MSI
Modem (real-time monitoring mode), or stores
measurements in the internal memory for trans-mission
later. A special mode of operation allows fast data
acquisition, at a rate of 40 measurements per second, so
that micro-profiles can be easily obtained. Moreover,
Timed Data Acquisition allows acquisition and
transmission at program-mable time intervals.
The internal non-volatile memory
can store up to 1,500 measurements, each composed of 8
parameters. A friendly menu-driven MMI (Man Machine In-terface)
allows the operator to interact with the internal
firmware to person-alize the operating functions and to
perform the sensor calibration. Com-mands are selected
from a list, or a menu, of possible choices. Parallel to
the menu interface, a computer-oriented interface has
been implemented, allowing execution of the data
acquisition and transmission to be performed in a quick
and efficient (from a Computer’s point of view) way. The
CDT 302 Probe is equipped with an MSI Modem system
(4,800 bps) that allows the connection of the Probe to
the Portable Deck Unit by means of a coaxial armoured
cable (2 wires). The cable also provides the mechanical
support of the Probe and its power supply.
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Sensor
Specifications |
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Range |
Accuracy |
Resolution |
Time Constant |
|
Pressure |
0.....1500
dbar* |
0.25% full
scale |
0.1 dbar
|
50 ms
|
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Temperature
|
-1 ... +49 ° C
|
0.02 °C 0.00
|
4°C
|
50 ms
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Conductivity
|
0..... 62 mS/cm**
|
0.02 mS/cm
|
0.004 mS/cm
|
50 ms(at 1
m/second flow rate ) |
|
Oxygen
|
0..... 50 ppm
|
0.1 ppm
|
0.01 ppm
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3 s (in air)
|
| |
0... 500% sat.
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1% sat.
|
0.1% sat.
|
3 s
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pH
|
0..... 14 pH
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0.05 pH
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0.01 pH
|
3 s
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Redox
|
-1000 to +
1000 m |
V 10 m
|
V 1 mV
|
3 s
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Nitrate
|
0 to 100
mg/l-N |
greater of ±5%
of reading or ±2 mg/l-N |
0.01 mg/l-N
|
3s
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* other standard
pressure transducers available have 20, 70 and
300 dbar ranges.
** a probe version with conductivity range for
fresh water is also available: |
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