CTD75M
Online and memory probe
The CTD75M probe is a medium sized microprocessor controlled multi-parameter probe for limnological measurement of physical, chemical and optical parameters with up to 8 sensors for depth up to 1000 m. It measures conductivity, temperature, and pressure as a standard configuration. Furthermore, it can be easily configured for a wider range of auxiliary sensors.
Sea & Sun Technology
Trappenkamp, DE
Description
Data are stored in a standard flash memory card with a capacity limited to 128 Mbytes by the internal firmware. Up to 3 000 000 CTD data sets can be recorded on this memory. The actual number depends on the selected storage options and the number of sensors adapted to the probe.
The CTD75M allows operation in different modes:
- Continuous mode: each data set is stored.
- Time mode: data sets are only stored at programmable intervals with several selectable schemes.
- Increment mode: data sets are stored at programmable depth increments, up to 255 files can be stored without the need for data retrieval in between.
- Online mode (RS-232).
The CTD75M is equipped with a 4 channel data acquisition system with 16 bit resolution. A high long-term stability and automatic self-calibration of the analogue digital converter guarantees stable and precise CTD measurements for many years.
The supplied Standard Data Acquisition Software package “SST-SDA” includes the handling of the logging process and the display of online or recorded data with a shared graphic user interface. The “SST-SDA” is a part of our shipment.
The probe power supply is activated by touching a reed contact with a magnetic rod, LED displays power supply status and optical control of memory access.
Standard models:
CTD75M:
Online and memory probe for measurement of conductivity, pressure, temperature + 4 optional sensors
Standard sensors:
- Conductivity (Š”)
- Temperature (T)
- Pressure (D)
Additional sensors:
- Oxygen
- Turbidity
- pH
- Redox (OPR)
- Fluorometer
- Light irradiance
- Transmissiometer
Calculated parameters:
- salinity
- sound velocity
- Kappa 25 mS/cm
- sigma
Main Features:
- low weight
- easy handling
- up to 8 sensors on the bottom cap
- non-corrosive titanium housing (titanium)
- depth range up to 1000 m
- SDA data acquisition software running under various versions of Microsoft Windows
(a part of the shipment) - calculations according to UNESCO formulas
Specifications
-
General
-
Weight in air [kg]
3.5
Diameter [mm]
75
Length [mm]
654
Housing Material
Titanium
Max. cable length [m]
2000
-
Observations
-
Min. depth increment [m]
0.01
Min. time increment [s]
0.2
Resolution of salinity [psu]
0.001
Uncertainty of salinity [psu]
0.002
Min. sound velocity [m/s]
1400
Max. sound velocity [m/s]
1600
Resolution of sound velocity [m/s]
0.05
Uncertainty of sound velocity [m/s]
0.1
-
Operation Characteristics
-
Data display on dedicated hardware
N
Method of first recording
internal /external
Display of analogue data
Y
-
Pressure, temperature and conductivity sensor
-
Pressure sensor
Y
Type of pressure sensor
piezo resistive
Resolution of pressure [% FS]
0.002
Accuracy of pressure sensor
0.05
Temperature sensor
Y
Type of temperature sensor
Pt 100 4-pole
Min. temperature [Ā°C]
-2
Max. temperature [Ā°C]
36
Resolution of temperature [Ā°C]
0.0005
Accuracy of temperature measurement
Ā± 0.002
Conductivity sensor
Y
Type of conductivity sensor
7-pole-cell
Max. conductivity [S/m]
70
Resolution of conductivity [10^-3 S/m]
0.0005
Accuracy of conductivity measurement
Ā± 0.002
Uncertainty of pressure [% FS]
130
-
Software specifications
-
Software name
SST-SDA
Graphical presentation
Y
Raw data editing
Y
Re-computation with raw data
Y
CTD Probe controller
Y
Recording with third party software
N
-
Environmental
-
Max. depth [m]
1000
Max. pressure [bar]
100
Operating temperature: min. [Ā°C]
-10
Operating temperature: max. [Ā°C]
60
-
Data and connectivity
-
Connectors
RS232
Internal memory
Y
Internal Memory [MB]
128
Direct data reading
Y
Type of internal memory
non-volatile memory
Max. number of samples for self-recording [10^3]
400000
Dedicated sub-surface data logger
Y
Dedicated surface data logger
Y
Telemetry link to remote location
Y
-
Power
-
Min. operating power [V]
7
Max. operating power [V]
15
Battery
Y
Battery type
Alkaline / Lithium
-
Additonal sensors
-
Standard sensor
pressure, temperature, conductivity
No. of additional sensors
5
Description of additional sensors
optical oxygen (SST-DO), dissolved oxygen, pH, Redox, turbidity, H2S, fluorometer, light irradiance, transmissometer
