SEALOGGER CTD  
SBE 25 w/ SBE 32 Carousel Water Sampler

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 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 5T 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 seven 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), 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 266 minutes with standard 1024K or up to 35 hours with 8 MB optional 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-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
• 1024 Kbyte memory
• 9 D-size alkaline batteries
• SBE 3F temperature, SBE 4 conductivity, and SBE 29 pressure sensor
• SBE 5T pump and T-C Duct
• Stainless steel cage

Options include:

• Aluminum housing for 3400 meter or 6800 meter depths
• 8 Mbyte memory
• Ni-Cad batteries and charger

SOFTWARE

SEASOFT©-Win32, our complete Windows 95/98/NT/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 or 8 hours with optional Ni-Cad batteries.

MEMORY AND COMMUNICATIONS

Memory Capacity is 1024K bytes standard (8 MB optional). Communications protocol is 600 to 38.4K baud (software selectable), 7 data bits, 1 stop bit, even parity. At maximum baud rate and 1024K byte memory, transfer time is approximately 10 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:

 ¹ Including all standard components and cage.

ADDITIONAL INFORMATION / LINKS:

• 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
  -- PN 90208 Auto Fire Module (AFM) for autonomous water sampling with SBE 25 on non-conducting cables