CTD48
Online probe
The CTD48 is a high quality, high accuracy 4 channel online probe for oceanographic and limnological measurement of conductivity, temperature, depth and one optional parameter for depth up to 6000 m. Standard models: CTD48: Online probe for measurement of conductivity, pressure, temperature + 1 optional sensor Standard sensors: Conductivity (С) Temperature (T) Pressure (D) Additional sensors: Dissolved Oxygen Turbidity pH Redox (OPR)
Sea & Sun Technology
Trappenkamp, DE
Description
The CTD48 is a very small and handy microprocessor controlled multiparameter probe for precise online measurements of pressure, temperature, conductivity and one optional parameter.
The probe is especially designed for limnological measurements on lakes, rivers and estuaries but can be used also in shallow water and in the oceanographic range up to 6000 m depth.
The CTD48 is equipped with a 4 channel data acquisition system with internal 20 bit resolution. Data output is 16 bit. A high long-term stability and automatic self-calibration of the analogue digital converter guarantees stable and precise CTD measurements for many years.
The CTD48 is equipped with several interfaces:
- RS-232
- RS-485
- FSK.
The RS-232 port can be used with multi-conductor cable up to distances of several hundred meters. The user can operate the probe easily from small boats and ships. The serial data will be applied directly to the serial port of a PC. Power has to be provided externally e.g. by a 12V battery or a regulated power supply.
RS-485 is used for data transfer in areas with high environmental electromagnetic noise, a safe data transmission requires cable with twisted pairs. RS-485 interface can drive up to 1000 m cable length on nearly any cable. The RS-485 signals need to be converted into RS-232 before being acquired by a PC.
FSK transmission is used mainly on single-conductor cables. Data is modulated on the power supply rail for a long distance data transmission. FSK operation requires a special power supply interface with a demodulator unit that converts the FSK data into RS-232 or USB 2.0 format.
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.
Standard models:
CTD48:
Online probe for measurement of conductivity, pressure, temperature + 1 optional sensor
Standard sensors:
- Conductivity (С)
- Temperature (T)
- Pressure (D)
Additional sensors:
- Dissolved Oxygen
- Turbidity
- pH
- Redox (OPR)
Calculated parameters:
- salinity
- sound velocity
- Kappa 25 mS/cm
- sigma
Main Features:
- low weight
- easy handling
- up to 4 sensors on the bottom cap
- non-corrosive titanium housing
- depth range up to 6000 m
- SDA data acquisition software running under various versions of Microsoft Windows (a part of the shipment)
- calculations according to UNESCO formulae
Specifications
-
General
-
Weight in air [kg]
1.2
Diameter [mm]
48
Length [mm]
450
Max. cable length [m]
6000
Housing Material
Titanium
-
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
external
Display of analogue data
Y
-
Pressure, temperature and conductivity sensor
-
Max. conductivity [S/m]
70
Resolution of conductivity [10^-3 S/m]
0.0001
Min. temperature [°C]
-2
Max. temperature [°C]
36
Resolution of temperature [°C]
0.0005
Resolution of pressure [% FS]
0.002
Pressure sensor
Y
Type of pressure sensor
piezo resistive
Accuracy of pressure sensor
up to 0.05 %
Temperature sensor
Y
Type of temperature sensor
Pt 100 4-pole
Accuracy of temperature measurement
0.002
Conductivity sensor
Y
Type of conductivity sensor
7-pole-cell
Accuracy of conductivity measurement
± 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]
6000
Max. pressure [bar]
600
Operating temperature: min. [°C]
-10
Operating temperature: max. [°C]
60
-
Data and connectivity
-
External recorder required
N
Dedicated surface data logger
N
Dedicated sub-surface data logger
N
Direct data reading
Y
Connectors
RS232
Internal memory
N
-
Power
-
Min. operating power [V]
9
Max. operating power [V]
30
Battery
N
-
Additonal sensors
-
Standard sensor
pressure, temperature, conductivity
Description of additional sensors
dissolved oxygen, pH, ORP, turbidity, H2S
No. of additional sensors
1
