CTD and Water Sampling

The system consists of a SBE9plus underwaterunit, a SBE11plusV2deckunit, a SBE32 caroussel, a SBE3plus thermometer, a SBE4 conductivity sensor, a SBE5T underwaterpump, a SBE43 dissolved oxygen sensor, a Chelsea Aquatracka MKIII fluorometer, a WetlabsC-Star transmissiometer (25 cm, deep, red), a Satlantic logaritmicPAR-sensor for underwater PAR  and a Satlantic lineair PAR-sensor for deck reference.

For watersampling 24 watersamplers manufactured by Ocean Test Equipment are available. These 12-liter samplers are equipped with external stainless steel springs.

For bottomdetection 2 devices are installed: A Benthos PSA-916 altimeter and a bottom switch with a weight. The SBE11+ has a NMEA interface for navigational data.  On board RV Pelagia a Seapath 2000 shipmotion sensor provides high accuracy position-, date- and time-data in NMEA-0183  RMC-format. On the logging computer Seasoft for Windows is installed (Seasave V7.20 and SBE Data Processing V7.20)

The CTD frame is made from stainless steel and consists of 2 parts: a core-part that contains all the electronic modules and an outer part containing the samplingbottles.

For CTD-operations during heavy seas a smaller outer frame without sampling-bottles is available. Detailed information about the sensors (e.g accuracy) and other system modules are available via the links.

When necessary extra sensors such as a secondary pumped CT-set, SBE35 reference-thermometer or SIS electronic reversing pressure meters (ERPM-6000X) are available.

Sven Ober
T +31 (0)222 369 413
@ sven.ober(at)nioz.nl

The system consists of 2 major modules:
A box-shaped titanium CTD frame with 24 PVDF sampling bottles with modified butterfly valves.
A clean air container for contamination-free (sub)sampling

For deployment of this CTD-system a winch with an iron free CTD-cable with a SWL of at least 2.5 ton is needed.

To avoid contamination the frame of the UCC-system is made of titanium. All electronic pressure housings and other parts are made of titanium or clean plastics like Teflon, PETP or POM. The frame can be parked and secured ‘seasave’ inside the clean air container. Prior to a cast the frame is prepared inside this container and transported to the CTD-launching spot using a custom made aluminium pallet and an extended forklift. After the cast the frame can be returned to the clear air container within minutes thereby avoiding contamination of the equipment with grease, rust or smoke particles from the ship. Once the container is closed the air treatment system starts to clean the air using HEPA-filters. Frame, bottles and electronics can be rinsed with fresh water. All the UCC-equipment, procedures and test results are described in a paper published in Marine Chemistry (pdf-version is available upon request, contact sven.ober@nioz.nl). A poster about the UCC-system is available for a first impression.

The electronic system consists of a SBE9plus underwaterunit, a SBE11plusV2 deckunit, a NIOZ-developed multivalve bottle-controller, a SBE3plus thermometer, a SBE4 conductivity sensor, a SBE5T underwaterpump, a SBE43 dissolved oxygen sensor, a Chelsea Aquatracka MKIII fluorometer, a Wetlabs C-Star transmissiometer (25 cm, deep, red), a Satlantic logaritmic PAR-sensor for underwater PAR and a Satlantic lineair PAR-sensor for deck reference.

For Ultra Clean water sampling 24 sampling bottles made of PVDF are used. These bottles with a volume of 27 liters have modified butterfly valves on both ends enabling a near-perfect flow of water through the bottle when going through the water column. The samplers are controlled with a hydraulic system. For bottom-detection 2 devices are installed: A Benthos PSA-916 altimeter and a bottom switch with a weight. The SBE11+ has a NMEA interface for navigational data. On the logging computer Seasoft for Windows is installed (Seasave V7.20 and SBE Data Processing V7.20).

General purpose high accuracy CTD-operations including large volume watersampling and the use of the following additional sensors:  fluorometer, DO sensor, PAR and transmissometer. This CTD-system is developed mainly to enable efficient sampling for research that needs large volumes of sample water e.g. research on rare elements, sedimentology and microbiology.

The system consists of a SBE9plus underwaterunit, a SBE11plusV2deckunit, a SBE32 caroussel, a SBE3plus thermometer, a SBE4 conductivity sensor, a SBE5T underwaterpump, a SBE43 dissolved oxygen sensor, a Chelsea Aquatracka MKIII fluorometer, a WetlabsC-Star transmissometer (25 cm, deep, red), a Satlantic logaritmicPAR-sensor for underwater PAR  and a Satlantic lineair PAR-sensorfor deck reference.

For large volume watersampling  24 watersamplers each with a volume of 25 liter manufactured by Ocean Test Equipment are applied. These 25-liter samplers are equipped with a internal stainless steel spring and a horizontally mounted Teflon drain assembly. Via this drain assembly flexible jerry cans can be filled easily and the horizontal orientation of the drain enables easy and efficient CFC-sampling.

For bottomdetection 2 devices are installed: A Benthos PSA-916 altimeter and a bottom switch with a weight. The SBE11+ has a NMEA interface for navigational data.  On the logging computerSeasoft for Windows is installed (Seasave V7.20 and SBE Data Processing V7.20).

The CTD frame is made of stainless steel and consists of 2 parts: a core-part that contains all the electronic modules and an outer part containing the sampling bottles.

Due to the large dimensions of the bottles the frame is rather big. It has a hexagonal shape with an overall diameter of about 2 m and a height of 1.9 meter. The mass of the frame with 24 filled bottles is about 1500 kg. Detailed information about the sensors (e.gaccuracy) and other system modules are available via the links. When necessary extra sensors such as a secondary pumped CT-set, SBE35 reference-thermometer or SIS electronic reversing pressure meters (ERPM-6000X) are available.

Sven Ober
T +31 (0)222 369 413
@ sven.ober(at)nioz.nl

This CTD is mounted in a small box-shaped stainless steel frame. Due to the small size  the drag from tidal currents is limited. Therefore, in combination with its weight, it is possible to obtain full profiles even during the high current phases of the tides.

In the past bigger frames (with samplingbottles) were applied, but these frames were often ‘ blown’ away by the currents.

The ‘bottom’ of the frame is half closed and the CTD is mounted relatively high in the frame. A bottom-touch is no problem at all. The frame just ‘lands’ on the seafloor and doesn’t penetrate the seafloor too much due to the half-closed bottom. The half-open bottom enables sufficient flow-through for the sensors of the CTD during lowering.

The CTD frame is made of stainless steel. The CTD including the wide-range conductivity sensor is mounted on a bracket occupying a bottle position.

Detailed information about the sensors (e.g. accuracy) and other system modules are available via the links.