SEALOGGER CTD  
SBE 25

Print version     Current Manual (for older manuals, click here)      Reference Sheet     Configuration options & accessories

The SBE 25 SEALOGGER CTD is the ideal research-quality CTD profiling system for coastal, estuarine, and budget-minded deep-water work. The SBE 25 is battery powered and is typically used to record data in memory, eliminating the need for a large vessel, electrical sea cable, and on-board computer. All SBE 25s can also operate in real-time, transmitting data via an opto-isolated RS-232 serial port.

SENSORS

Temperature and conductivity are measured by our modular SBE 3F Temperature sensor and SBE 4 Conductivity sensor (same as those used on our premium SBE 9plus CTD). The SBE 25 also includes the SBE 5P (plastic) or 5T (titanium) Submersible Pump and TC Duct. The pump-controlled, TC-ducted flow configuration significantly reduces salinity spiking caused by ship heave, and in calm waters allows slower descent rates for improved resolution of water column features. Pressure is measured by the modular SBE 29 Temperature Compensated Strain-Gauge Pressure sensor (available in eight depth ranges to suit the operating depth requirement).

The SBE 25's modular design makes it easy for users to add more sensors without sending it back to the factory. All SBE 25s include interface electronics for optional dissolved oxygen (SBE 43), pH (SBE 18 or SBE 27), fluorescence, transmissivity, PAR, and optical backscatter sensors.

OPERATION

The SBE 25's scan rate of 8 Hz provides good fine-scale measurement performance and recording endurance of up to 35 hours with standard 8 MB memory. To optimize the use of memory space, the SBE 25 is software configurable for any combination of sensors used. Recording endurance can be extended by programming the SBE 25 to average the 8 Hz data over longer intervals. Simultaneous with recording, real-time data an be transmitted over single-core, armored cable directly to your PC's serial port (maximum transmission distance dependent on number of auxiliary sensors, baud rate, and cable properties). Recorded data are transferred via RS-232 interface to a computer for processing. Alkaline or rechargeable Nickel Metal Hydride or Nickel-Cadmium batteries can be used. External power and two-way real-time communication over 10,000 meters of cable can be provided with the SBE 36 CTD Deck Unit and the Power and Data Interface Module (PDIM).

CONFIGURATION AND OPTIONS

A standard SBE 25 is supplied with:

• Plastic housing for depths to 600 meters
• 8 Mbyte memory
• 9 D-size alkaline batteries (Duracell MN1300, LR20)
• SBE 3F temperature, SBE 4 conductivity, and SBE 29 pressure sensor
• SBE 5P plastic pump (for depths to 600 meters) and T-C Duct
• Glass-reinforced epoxy bulkhead connectors
• Stainless steel cage

Options include:

• Aluminum housing for 6800 meter depths
• SBE 5T titanium pump in place of SBE 5P pump
• Auxiliary sensors for Dissolved Oxygen (SBE 43 DO Sensor), pH (SBE 18 pH Sensor or SBE 27 pH/ORP Sensor), fluorescence, radiance (PAR), light transmission, and optical backscatter (turbidity)
• Nickel Metal Hydride (NiMH) batteries and charger

SOFTWARE

SEASOFT^© V2, our complete Windows 2000/XP software package, is included at no extra charge. Its modular programs include:

• Seaterm^© -- communication and data retrieval
• Seasave^© -- real-time data acquisition and display
• SBE Data Processing^© -- filtering, aligning, averaging, and plotting of CTD and auxiliary sensor data and derived variables

AUXILIARY INPUTS

SEALOGGER CTD has seven 12-bit A/D input channels for optional auxiliary sensors: 4 single-ended, 2 differential (for fluorometer), and 1 log amplified (for PAR sensor).

BATTERY ENDURANCE (NOMINAL)

Battery endurance is approximately 24 hours with standard alkaline batteries, 17 hours with optional NiMH batteries, or 8 hours with optional Ni-Cad batteries.

MEMORY AND COMMUNICATIONS

Memory capacity is 8 MByte. Communications protocol is 600 to 38.4K baud (software selectable), 7 data bits, 1 stop bit, even parity. At maximum baud rate and 8 MByte memory, transfer time is approximately 80 minutes.

Each sample (scan) of temperature, conductivity, and pressure uses 8 bytes. Up to 7 auxiliary voltages can be logged, each requiring 1.5 bytes per sample. Maximum configuration of CTD and auxiliary voltages is 18.5 bytes per scan.

SPECIFICATIONS

Mechanical:

ADDITIONAL INFORMATION / LINKS:

Documentation -- manual, photos, technical papers, application notes, etc.

• Current product manual (for older manuals, click here)
• Photo Gallery
• Optional ice cage (photo)
• Print version of this specification sheet/brochure
• Application Notes:
  - 2D: Instructions for Care and Cleaning of Conductivity Cells
  - 6: Determination of Sound Velocity from CTD Data
  - 10: Compressibility Compensation of Sea-Bird Conductivity Sensors
  - 12-1: Pressure Port Oil Refill Procedure and Nylon Capillary Fitting Replacement
  - 14: 1978 Practical Salinity Scale
  - 15: TC Duct Assembly & Plumbing Installation
  - 21: Instructions for Use of Ni-Cad Battery Packs
  - 27Druck: (Druck) Strain Gauge Pressure Sensor Error Sources
  - 34: Conductivity Cell Filling and Storage Device P/N 50087
  - 36a: Installation of P/N 50094 Conductivity Cell Tubing Connector Kit
  - 38: TC Duct Fundamentals
  - 42: ITS-90 Temperature Scale
  - 43: Universal Ni-Cad Battery Charger Operating Instructions
  - 59: A Load-Bearing Underwater Cable for Hand-Hauled, Real-Time Profiling
  - 64-1: Plumbing Installation -- SBE 43 DO Sensor and Pump on a CTD
  - 67: Editing Sea-Bird .hex Data Files
  - 68: Using USB Ports to Communicate with Sea-Bird Instruments
  - 69: Conversion of Pressure to Depth
  - 71: Desiccant Use and Regeneration (drying)
  - 73: Using Instruments with Pressure Sensors at Elevations Above Sea Level
  - 75: Maintenance of SBE 5T, 5P, and 5M Pumps
  - 90: Absolute Salinity and TEOS-10: Sea-Bird's Implementation Plans
• Removing the TC Duct for Temperature/Conductivity sensor return for calibration

Sales Information -- options, accessories, cables, mount kits, spares, etc.

• Configuration options & accessories:
  - Details for SBE 25
  - Listing for all products
• Cables
• Mount kits -- for Sea-Bird instruments     for Third Party instruments
• Spare parts

Software -- components of Seasoft V2

• Seaterm -- description, download
• Seasave V7 -- description, download
• SBE Data Processing -- description, download

Links to Other Instruments of Interest

• Pumps:
  - SBE 5P Plastic Submersible Pump -- standard equipment supplied with SBE 25
  - SBE 5T Titanium Submersible Pump -- optional equipment supplied with SBE 25
• SBE 32 Carousel Water Sampler with:
  - SBE 33 Deck Unit for real-time control of water sampling as well as power for SBE 25 and auxiliary instruments.
  - Auto Fire Module (AFM) for autonomous water sampling with SBE 25 on non-conducting cables.
• SBE 55 ECO Water Sampler with:
  - SBE 33 Deck Unit for real-time control of water sampling as well as power for SBE 25 and auxiliary instruments.
  - Built-in electronics for autonomous water sampling with SBE 25 on non-conducting cables.
• SBE 36 CTD Deck Unit and the Power and Data Interface Module (PDIM) -- provides external power and two-way real-time communication for SBE 25
• SBE 14 Remote Depth Readout -- rugged, spray-proof display box suitable for mounting at winch operator's position
• Load-Bearing Cable for Hand-Hauled, Real-Time Profiling
• Other CTDs:
  - SBE 9plus -- premium CTD, faster sampling, can acquire data from more auxiliary sensors
  - SBE 19plus V2 -- small, economical CTD, can acquire data from auxiliary sensors
  - SBE 49 -- CTD for towed vehicles, ROVs, AUVs, etc.
  - SBE 52-MP -- CTD for moored profiling applications
  - Glider Payload CTD (GPCTD) -- CTD for autonomous gliders

Specifications are subject to change without notice.

Last modified: 06-Apr-2011

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