SBE 911plus CTD
- Sea-Bird's 911plus CTD is the primary oceanographic research tool chosen by the world's leading institutions
- Accurate and stable, modular Conductivity and Temperature sensors
- Paroscientific Digiquartz® pressure sensor
- TC-ducted flow and pump-controlled time responses to minimize salinity spiking
- 24 Hz all-channel scan rate
- Depth capability 6800 meters (22,300 ft) (aluminum) or 10500 meters (34,400 ft) (titanium)
- Built-in interface for dual C & T sensors (sensors optional)
- 8 A/D channels and high power capability for auxiliary sensors
- Modem channel for real-time water sampler control (without data interruption)
- Built-in NMEA 0183 interface to merge real-time GPS data with the CTD data
- Optional Serial Data Uplink allows 9600 baud data pass-thru on shared CTD telemetry channel
- Optional RS-232 serial output interface for use with AUV/ROV logging CTD data
- Optional SBE 17plus V2 Searam module for in-situ recording and programmable Carousel bottle firing
- Powerful Windows software included
- Five-year limited warranty
The 911plus CTD system includes:
- SBE 9plus Underwater Unit with sensors for C, T, and P and a submersible pump
- optional auxiliary sensors (dissolved oxygen, chlorophyll, etc.)
- SBE 11plus V2 Deck Unit
For real-time data collection, an electro-mechanical sea cable (single- or multi-conductor), a slip-ring equipped winch, and computer for data display and logging are typically supplied by the user. An optional SBE 17plus V2 Searam Recorder and Auto Fire Module provides in-situ recording and self-contained CTD operation, and can be user-programmed to trigger bottle closure on a Carousel Water Sampler, eliminating the need for the Deck Unit, conductive sea cable, and slip-ring equipped winch.
SBE 9plus Underwater Unit
The standard SBE 9plus underwater unit has an aluminum housing rated to 6800 meters (22,300 ft), and is supplied with one conductivity and one temperature sensor (fitted with a TC Duct and constant-flow pump), and an internally mounted, temperature-compensated Paroscientific Digiquartz pressure sensor for 6800 meter (10,000 psia) full scale range. Input channels and bulkhead connectors are provided for an optional second (redundant) pair of temperature and conductivity sensors. Other standard features include an 8-channel, 12-bit A/D converter with differential inputs and low pass filters, and high-power capability for support of commonly used auxiliary sensors (e.g., SBE 43 dissolved oxygen, SBE 18 pH or SBE 27 pH, transmissometer, fluorometer, ambient light, altimeter), a modem channel for real-time water sampler control, and a port for connection of an optional bottom contact switch. Options include:
- other pressure sensor ranges - 1400, 2000, 4200, 10,500 meters (2000, 3000, 6000, or 15,000 psia)
- 10500 meter (34,400 ft) titanium housing
SBE 11plus V2 Deck Unit
SBE 11plus V2 Deck Unit includes RS-232 and IEEE-488 computer interfaces, a modem channel for real-time water sampler control (including water sampler control push buttons and status lights), NMEA 0183 interface for adding GPS position to CTD data, 12-bit A/D input channel for surface PAR sensor, switch-selectable 115/230 VAC operation, audio tape interface (data backup), LED readout for raw data, and audible bottom contact (or altimeter) alarm. The 11plus V2 also provides a remote pressure output (useful as an input signal for towed vehicle control) and a programmable serial ASCII data output containing up to seven variables in computed engineering units. Calibration coefficients are stored in EEPROM, and a separate microcontroller converts raw CTD data to temperature, depth, salinity, etc. The 11plus V2 is shipped in a free-standing cabinet with a hardware kit for mounting in a standard 19-inch electronics rack.
SBE 17plus V2 Searam Memory and Auto Fire Module (see Searam brochure for details)
The Searam provides battery power for the SBE 9plus CTD and SBE 32 Carousel Water Sampler, memory for CTD data recording, and autonomous water sampler control (Auto-Fire). Each time the Searam's magnetic on/off switch is activated, date, time, and sequential cast number is recorded. The 16 Mbyte memory provides approximately 15 hours recording of C, T, and P at 24 Hz (6 hours with all auxiliary channels used), and the Searam can average samples for longer recording endurance. It can be programmed before deployment to decode pressure data from the 9plus and fire bottles at user-programmed depths, allowing autonomous water sampling and CTD recording without a conductive sea cable. Data upload requires about 12 minutes per Mbyte at 38,400 baud. The Searam includes a Nickel-Metal hydride (NiMH) rechargeable battery park and a charger.
When the SBE 9plus is equipped with the Searam, the system is referred to as the 917plus.
SOFTWARE — Seasoft© V2
Supplied with each SBE 911plus, Seasoft calculates a suite of seawater parameters, including salinity, density, buoyancy, sound velocity, etc., and fully supports auxiliary sensors for oxygen, light transmission, PAR, fluorescence, and many other variables. Seasoft provides real-time plots or number readouts while saving raw data to a disk file from which an ASCII or binary intermediate file in engineering units may subsequently be made. Post-processing utilities provide bin averaging, wild point editing, filtering, time-aligning, and color video graphing / hard copy plotting of profiles, waterfall overlays, and density-contoured TS plots. When operating the 911plus with a water sampler, complete bottle housekeeping files based on firing confirmations are recorded. Seasoft is upgraded frequently; new versions are supplied free to 911plus users and posted on our website for easy access.
The temperature sensor (SBE 3plus) is a compact module containing a pressure-protected, high-speed thermistor and Wien-bridge-oscillator interface electronics. The thermistor is the variable element in the Wien bridge, while a precision Vishay resistor and two ultra-stable capacitors form the fixed components.
The conductivity sensor (SBE 4C) is similar in operation and configuration to the temperature sensor, except that the Wien-bridge variable element is the cell resistance (cell resistance is the reciprocal of cell conductivity).
The Digiquartz® pressure sensor also provides a variable frequency output. Embedded in the pressure sensor is a semiconductor temperature sensor used to compensate the small ambient temperature sensitivity of the Digiquartz.
The calibration information for each sensor (C, T, and P) is contained in a series of numeric coefficients used in equations relating frequency to the measured parameter.
The SBE 11plus V2 Deck Unit provides power to the sea cable, decodes the data arriving from the underwater unit, and interfaces to a computer via RS-232 or IEEE-488. Push buttons and status lights for SBE 32 Carousel Water Sampler operation are provided, and there are connections for back-up data recording and playback using an audio tape recorder. The SBE 9plus underwater unit comprises modular temperature and conductivity sensors, a small external pump, and a main housing supplied with surface power from the sea cable. Electronics in the main housing provide three primary functions: regulation of the several voltage levels required by the internal circuits, external sensors, and pump; acquisition (digitization) of sensor signals; and data telemetry.
Sea Cable Power Supply
Unlike competing CTD systems in which the deck unit supplies a fixed current, the SBE 11plus V2 presents a constant voltage to the sea cable. The SBE 9plus receives this voltage (minus the sea cable I-R drop), regulates it to a constant value, and presents it to a high-efficiency DC/DC converter that generates the system supply voltages (+14.3/-13.5, +8, and +5). Two advantages derive from this method: less power is lost in the sea cable (and more is delivered to the underwater unit); and the underwater unit is not required to dissipate unneeded power (freeing the user of the need to monitor and adjust the surface sea cable supply).
Signal Acquisition and Data Telemetry
Connectors on the SBE 9plus bottom end cap supply power to (and receive variable frequencies from) the modular conductivity and temperature sensors. The C and T variable frequencies plus the internal Digiquartz frequency are routed to separate counters that are allotted exactly 1/24 second to derive 24-bit binary values representative of each sensor frequency. Sea-Bird's hybrid counter technique combines integer and period counting to produce digital results that are simultaneous (time coincident) integrals of C, T, and P. The 9plus provides four bulkhead connectors for optional auxiliary sensor inputs. Each connector provides +14.3 volts power and permits access to two differentially amplified and low pass filtered digitizer channels with 0 to 5 volt range and 12-bit resolution. Binary data from the entire suite of C, T, P, and auxiliary sensors are transmitted serially 24 times per second using a 34560 Hz carrier differential-phase-shift-keyed (DPSK) technique. This telemetry system is suitable for all single and multi-conductor sea cables having a conductor resistance of 350 ohms or less.
Subcarrier Modem and SBE 32 Carousel Water Sampler Control
A 300 baud full duplex FSK subcarrier modem (2025/2225 Hz downlink; 1070/1270 Hz uplink) provides a separate communications channel for control of the Carousel. Bottles can be fired with push buttons on the deck unit's front panel, through SEASOFT©, or via a separate computer connected directly to the modem port on the deck unit's back panel. There is no interruption of CTD power or data during the bottle firing process. An optional interface card in the SBE 9plus permits control of older multi-bottle sampler types, and the modem channel is also available as a general purpose RS-232 interface for custom user applications.
METROLOGY STANDARDS & CALIBRATION LABORATORY
Following consultation with the US National Institute of Standards and Technology, Sea-Bird's metrology lab was configured to achieve temperature precision of 50 µK and accuracy of 0.0005° C. To obtain this performance, premium primary references, including four Jarrett water triple-point cells (with maintenance bath) and an Isotech gallium melt cell, are operated in conjunction with two YSI 8163 standards-grade platinum resistance thermometers and an ASL Model F18 Automatic Temperature Bridge. IAPSO standard seawater and a Guildline 8400B AutoSal provide the highest obtainable salinity accuracy of 0.002 PSU.
SBE 911plus temperature and conductivity sensors are calibrated in low-gradient, computer-controlled baths capable of transferring Sea-Bird metrology lab accuracies within 0.0005° C and 0.001 PSU.
Calibration data from Sea-Bird's computer-controlled baths are collated to produce certificates showing the latest results. Overplots of previous calibrations allow the user to judge the stability of the sensor over time.
SBE 911plus Digiquartz pressure calibrations are performed by Paroscientific, Inc. using a DH Model 5206 Primary Pressure Standard (oil-operated dead weight tester) certified to an accuracy of 0.01% of reading (0.7 dbar at 6800 meters depth). Cross-comparison against independent standards has established the consistent accuracy of the Paroscientific calibrations.
Accuracy and stability of the SBE 911plus quartz master clock is judged against a Spectracom Model 8163 reference oscillator phase-locked to the U.S. National Institute of Standards and Technology's WWVB 60 kHz broadcast signal.
SYSTEM ENGINEERING & FUNDAMENTAL PRINCIPLES OF CTD ACCURACY
The SBE 911plus CTD produces profiles of ocean temperature, salinity, and density at the highest possible absolute accuracy, because its performance under both static and dynamic conditions has been optimized. Static accuracy (as demonstrated in an equilibrated calibration bath) ensures that the deep-ocean readings will be correct and allows meaningful comparison of results obtained by different researchers at different times and places. Dynamic accuracy is necessary to present water column features in clear detail, and is critical for maintaining absolute accuracy under oceanic (non-equilibrated) conditions. This is because salinity, density, and other oceanographic variables are calculated from separate measurements of pressure, temperature, and conductivity. If the calculated values are to be correct, the separate measurements must be made at the same time and on the same sample of water.
Time response and spatial mismatches not only create spiking, but also produce bias errors that are indistinguishable from static errors because they cannot be averaged out. For example, if the temperature sensor responds slowly, averaging its readings through a temperature gradient will produce a bias error of sign opposite to the gradient. Similarly, the spiking caused by a mismatch in time-response of the temperature and conductivity sensors will bias the results unless the correct time lag is applied in post-processing. Corrections are possible in practice only if the sensor time responses are constant, a condition that cannot be met by free-flushing (unpumped) conductivity sensors. The time responses of free-flushing sensors are inevitably affected by the influence of ship-coupled motion on profiling speed.
To obtain the highest possible absolute accuracy, the SBE 911plus CTD incorporates certain key features:
- A single temperature sensor that is both accurate and fast
- A conductivity sensor with a totally internal field that is immune to proximity effects
- Constant (pumped) flow, providing constant time responses in T and C
- A TC Duct to ensure that the temperature and conductivity sensors measure the same water
- A dramatically superior quartz pressure sensor
- Modular sensors that can be separately calibrated
- Acquisition electronics free of significant error
The temperature accuracy that can be achieved under controlled laboratory conditions with an SPRT (Standards-grade Platinum Resistance Thermometer) cannot be obtained in the ocean with the industrial-grade PRTs used in competing CTD instruments. The 911plus thermistor sensor's better ocean accuracy derives from its 10 times higher sensitivity and 100 times higher absolute resistance (at the ice-point, the thermistor resistance changes by about 1 ohm/mK while the resistance of a PRT changes by about 0.001 ohm/mK), its inherently fast response that eliminates the need for fast and slow sensor combinations (and the errors that arise when merging data from separate sensors), and because it is not measurably affected by shock and vibration.
Sea-Bird's conductivity cell designs reflect our recognition that the primary causes of conductivity errors are mineral and biological deposits on the sensor, proximity effects arising from external fields, and uncontrolled time-responses. Deposits occur with all conductivity sensor designs (they are more serious with sensors that are smaller than Sea-Bird's) and can be minimized by periodic detergent and bleach cleaning of the cell. The four-electrode and inductive-cell types used on competing CTDs have significant external fields that often completely preclude high-accuracy laboratory calibration and that lead to in-situ proximity errors induced by guards, mounting brackets, and other nearby sensors. Sea-Bird's totally internal field conductivity cell eliminates proximity errors, permits constant-flow pumping to control time response, and is connected to the temperature sensor by the TC Duct to ensure that the measurements of T and C are made on exactly the same water.
The highest possible pressure accuracy is obtained by using the Paroscientific Digiquartz® pressure sensor. The inexpensive pressure sensors used in other CTD systems have excessive hysteresis and thermal transient errors, requiring costly sensor-specific characterization and tedious post-processing. Sea-Bird's choice of a costly, but dramatically superior, pressure sensor eliminates most of these errors before they get into the data set. Careful shock mounting of the Digiquartz has resulted in negligible failure rates.
The SBE 911plus' modular sensors can be calibrated in well-insulated temperature/salinity baths that have smaller gradients and better accuracy than baths build to accommodate (and absorb the heat produced by) an integrated CTD. Unlike some competing sensor designs where trim pots are adjusted and drift history is lost each time a calibration is performed, the Sea-Bird calibrations are preserved as sets of numerical coefficients. As a result, all calibrations of Sea-Bird sensors can be compared and a complete drift history established (Sea-Bird maintains such histories - some of them spanning more than 20 years - on thousands of sensors). The information in these histories continues to play an important role in Sea-Bird's ongoing improvements to its sensor designs.
The SBE 911plus sensors can be calibrated separately without significant loss of overall CTD accuracy because the SBE 9plus digitizes the temperature, conductivity, and pressure sensor output signals by frequency counting, an inherently binary process whereby a count either registers or does not. Cable resistance, connector properties, and noise cannot degrade the overall system acquisition accuracy, which is limited only by the stability of a quartz master clock. Errors attributable to this clock are demonstrably negligible.
While competing designs occasionally offer elegant solutions to part of the CTD measurement problem, we have carefully balanced the engineering trade-offs to get better overall results. The SBE 911plus has the ability — under conditions of rapidly changing temperature and immense pressure loading — to obtain the independent measurements precisely coordinated in space and time that are the essence of CTD accuracy. Its design is a synthesis of ideas based upon a thorough understanding of the marine environment, the operational requirements of oceanographers, and the fundamental principles affecting CTD accuracy. System Engineering has made the 911plus CTD the World's Most Accurate CTD.
0 - 7 S/m
-5 to +35 °C
0 to full scale — 1400/2000/4200/6800/10,500 m (2000/3000/6000/10,000/15,000 psia)
0 to +5 volts
0.015% of full scale
0.0002 °C per month
0.02% of full scale per year
0.001 volts per month
|Resolution at 24 Hz||
0.001% of full scale
|Time Response 1||
5.5 Hz 2-pole
|Master Clock Error Contribution 2||
0.3 dbar with 6800 m (10,000 psia) pressure sensor
|1 Single pole approximation including sensor and acquisition system contributions.
2 Based on five-year worst-case error budget including ambient temperature influence of 1 ppm total over -20 to +70 °C plus 1 ppm first year drift plus four additional year's drift at 0.3 ppm per year.
|Weight in air,
|Weight in water,
|SBE 9plus with Aluminum housing||25 (55)||16 (35)||952 x 330 x 305
(37.5 x 13 x 12)
|SBE 9plus with Titanium housing||29 (65)||20 (45)|
|SBE 11plus||10 (23)||Not applicable||132 x 432 x 432
(5.2 x 17 x 17)
|SBE 17plus with Aluminum housing||8 (18)||3.7 (8)||711 x 99
(28 x 3.9)
|SBE 17plus with Titanium housing||12 (26)||7.3 (16)|
- SBE 9plus: power available for auxiliary sensors 1 amp at +14.3 volts
- SBE 11plus V2: AC power requirement 130 watts at 115 or 230 VAC 50-400 Hz
- Sea cable inner conductor resistance: 0 to 350 ohms
- Subcarrier modem baud rate: 300 baud (30 characters per second, full duplex)
How should I handle my CTD to avoid cracking the conductivity cell?
Shipping: Sea-Bird carefully packs the CTD in foam for shipping. If you are shipping the CTD or conductivity sensor, carefully pack the instrument using the original crate and packing materials, or suitable substitutes.
Use: Cracks at the C-Duct end of the conductivity cell are most often caused by:
- Hitting the bottom, which can cause the T-C Duct to flex, resulting in cracking at the end of the cell.
- Removing the soaker tube from the T-C duct in a rough manner, which also causes the T-C Duct to flex. Pulling the soaker tube off at an angle can be especially damaging over time to the cell. Pull the soaker tube off straight down and gently.
- Improper disassembly of the T-C ducted temperature and conductivity sensors (SBE 25, 25plus, and 9plus) when removing them for shipment to Sea-Bird for calibration. See Shipping SBE 9plus, 25, and 25plus Temperature and Conductivity Sensors for the correct procedure.
Note: If a Tygon tube attached to the conductivity cell has dried out, yellowed, or become difficult to remove, slice (with a razor knife or blade) and peel the tube off of the conductivity cell rather than twisting or pulling the tube off.
I sent my conductivity sensor to Sea-Bird for calibration, and you also performed a Cleaning and Replatinizing (C &P). You sent the instrument back with 2 sets of calibration data. What does this mean?
The post-cruise calibration contains important information for drift calculations. The post-cruise calibration is performed on the cell as we received it from you, and is an indicator of how much the sensor has drifted in the field. Information from the post-cruise calibration can be used to adjust your data, based on the sensor’s drift over time. See Application Note 31: Computing Temperature and Conductivity Slope and Offset Correction Coefficients from Laboratory Calibrations and Salinity Bottle Samples.
If the sensor has drifted significantly (based on the data from the post-cruise calibration), Sea-Bird performs a C & P to restore the cell to a state similar to the original calibration. After the C & P, the sensor is calibrated again. This calibration serves as the starting point for future data, and for the sensor’s next drift calculation.
The C & P tends to return the cell to its original state. However, there are many subtle factors that may result in the post-C & P calibration not exactly matching the original calibration. Basically, the old platinizing is stripped off and new platinizing is plated on. Anything in this process that alters the cell slightly will result in a difference from the original calibration. We compare the calibration after C & P with the original calibration, not to make any drift analysis, but to make sure we did not drastically alter the cell, or that the cell was not damaged during the C & P process.
Can I use a pressure sensor above its rated pressure?
Digiquartz pressure sensors are used in the SBE 9plus, 53, and 54. The SBE 16plus V2, 16plus-IM V2, 19plus V2, and 26plus can be equipped with either a Druck pressure sensor or a Digiquartz pressure sensor. All other instruments that include pressure use a Druck pressure sensor.
- The overpressure rating for a Digiquartz (as stated by Paroscientific) is 1.2 * full scale. The sensor will provide data values above 100% of rated full scale; however, Sea-Bird does not calibrate beyond the rated full scale.
- The overpressure rating for a Druck (as stated by Druck) is 1.5 * full scale. The sensor will provide data values above 100% of rated full scale; however, Sea-Bird does not calibrate beyond the rated full scale.
Note: If you use the instrument above the rated range, you do so at your own risk; the product will not be covered under warranty.
Why and how should I align data from a 911plus CTD?
The T-C Duct on a 911plus imposes a fixed delay (lag time) between the temperature measurement and the conductivity measurement reported in a given data scan. The delay is due to the time it takes for water to transit from the thermistor to the conductivity cell, and is determined by flow rate (pump rate). The average flow rate for a 9plus is about 30 ml/sec. The Deck Unit (11plus) automatically advances conductivity (moves it forward in time relative to temperature) on the fly by a user-programmable amount (default value of 0.073 seconds), before the data is logged on your computer. This default value is about right for a typical 9plus flow rate. Any fine-tuning adjustments to this advance are determined by looking for salinity spikes corresponding to sharp temperature steps in the profile and, via the SBE Data Processing module Align CTD, trying different additions (+ or -) to the 0.073 seconds applied by the Deck Unit, until the spikes are minimized. Having found this optimum advance for your CTD (corresponding to its particular flow rate), you can use that value for all future casts (change the value in the Deck Unit) unless the CTD plumbing (hence flow rate) is changed.
Oxygen and other parameters from pumped sensors in the same flow as the CT sensors can also be re-aligned in time relative to temperature, to account for the transit time of water through the plumbing. A typical plumbing delay for the SBE 43 DO Sensor is 2 seconds. However, the DO sensor time constant varies from approximately 2 seconds at 25 °C to 5 seconds at 0 °C. So, you should add some advance time for this as well (total delay = plumbing delay + response time). As for the conductivity alignment, the Deck Unit can automatically advance oxygen on the fly by a user-programmable amount (default value of 0 seconds) before the data is logged on your computer. However, because there is more variability in the advance, most users choose to do the advance in post-processing, via the SBE Data Processing module Align CTD. For additional information and discussion, refer to Module 9 of our training class and the SBE Data Processing manual.
Note: Alignment values are actually entered in the 11plus Deck Unit and in SBE Data Processing relative to the pressure measurement. For the 9plus, it is sufficiently correct to assume that the temperature measurement is made at the same instant in time and space as the pressure measurement.
How can I tell if the conductivity cell on my CTD is broken?
Conductivity cells are made of glass, which is breakable.
- If a cell is cracked, it typically causes a salinity shift or erratic data.
- However, if the crack occurs at the end of the cell, the sensor will continue to function normally until water penetrates the epoxy jacket. Post-cruise calibration results will reveal whether or not water has penetrated the epoxy jacket.
Inspect the cell thoroughly and make sure that it isn’t cracked or abused in any way.
- (SBE 9plus, 25, or 25plus) If the readings are good at the surface but erratic at depth, it is likely that the problem is in the cable or the connector, not the conductivity cell. Check the connections, making sure that you burp the connectors when you plug them in (see Application Note 57: Connector Care and Cable Installation). Check the cable itself (swap with a spare cable, if available).
- If the readings are incorrect at the surface but good after a few meters, it is likely that the problem is flow-related. Verify that the pump is working properly. Check the air bleed valve (the white plastic piece in the Y-fitting, which is installed on vertically deployed CTDs) to see if it is clogged; clean out the small hole with a piece of fine wire supplied with your CTD.
- If the readings are incorrect for the entire cast, there may be an incorrect calibration coefficient or the cell may be cracked.
- Check the conductivity calibration coefficients in the configuration (.con or .xmlcon) file.
- Do a frequency check on the conductivity cell. Disconnect the plumbing on the cell. Rinse the cell with distilled or de-ionized water and blow it dry (use your mouth and not compressed air, as there tends to be oil in the air lines on ships). With the cell completely dry, check the frequency reading. It should read within a few tenths of a Hz of the 0 reading on your Calibration Sheet. If it does not, something is wrong with the cell and it needs to be repaired.
What is the function of the zinc anode on some instruments?
A zinc anode attracts corrosion and prevents aluminum from corroding until all the zinc is eaten up. Sea-Bird uses zinc anodes on an instrument if it has an aluminum housing and/or end cap. Instruments with titanium or plastic housings and end caps (for example, SBE 37 MicroCAT) do not require an anode.
Check the anode(s) periodically to verify that it is securely fastened and has not been eaten away.
What are the typical data processing steps recommended for each instrument?
Section 3: Typical Data Processing Sequences in the SBE Data Processing manual provides typical data processing sequences for our profiling CTDs, moored CTDs, and thermosalinographs. Typical values for aligning, filtering, etc. are provided in the sections detailing each module of the software. This information is also documented in the software's Help file. To download the software and/or manual, go to SBE Data Processing.
Should I purchase spare sensors for my SBE 9plus or 25plus?
Most customers purchase spare conductivity and temperature sensors. These sensors are exposed to ocean conditions and therefore more likely to be broken than an internal sensor. It is also very easy to change them because they are independent sensors that plug into the CTD main housing.
Most customers do not purchase spare pressure sensors for the following reasons:
- The pressure sensor is inside the CTD main housing. It is very well protected against damage of any kind, and reliability of this sensor is extremely good.
- The sensor is expensive.
- It is difficult to change the sensor in the field.
Which Sea-Bird profiling CTD is best for my application?
Sea-Bird makes four main profiling CTD instruments, as well as several profiling CTD instruments for specialized applications.
In order of decreasing cost, the four main profiling CTD instruments are the SBE 911plus CTD, SBE 25plus Sealogger CTD, SBE 19plus SeaCAT Profiler CTD, and SBE 49 FastCAT CTD Sensor:
- The SBE 911plus is the world’s most accurate CTD. Used by most leading oceanographic institutions, the SBE 911plus is recognized for superior performance, reliability, and ease-of-use. Features include: modular conductivity and temperature sensors, Digiquartz pressure sensor, TC-Ducted Flow and pump-controlled time response, 24 Hz sampling, 8 A/D channels and power for auxiliary sensors, modem channel for real-time water sampler control without data interruption, and optional 9600 baud serial data uplink. The SBE 911plus system consists of: SBE 9plus Underwater Unit and SBE 11plus Deck Unit. The SBE 9plus can be used in self-contained mode when integrated with the optional SBE 17plus V2 Searam. The Searam provides battery power, internal 24 Hz data logging, and an auto-fire interface to an SBE 32 Carousel Water Sampler to trigger bottle closures at pre-programmed depths.
- The SBE 25plus Sealogger is the choice for research work from smaller vessel not equipped for real-time operation, or use by multi-discipline scientific groups requiring configuration flexibility and good accuracy and resolution on a smaller budget. The SBE 25plus is a battery-powered, internally-recording CTD featuring the same modular C & T sensors used on the SBE 9plus CTD, an integral strain gauge pressure sensor, 16 Hz sampling, 2 GB of memory, TC-Ducted Flow and pump-controlled time response, and 8 A/D channels plus 2 RS-232 channels and power for auxiliary sensors. Real-time data can be transmitted via RS-232 simultaneous with data recording. The SBE 25plus integrates easily with an SBE 32 Carousel Water Sampler or SBE 55 ECO Water Sampler for real-time or autonomous operation.
- The SBE 19plus V2 SeaCAT Profiler is known throughout the world for good performance, reliability, and ease-of-use. An economical, battery-powered, internally-recording mini-CTD, the SBE 19plus V2 is a good choice for basic hydrography, fisheries research, environmental monitoring, and sound velocity profiling. Features include 4 Hz sampling, 6 differential A/D channels plus 1 RS-232 channel and power for auxiliary sensors, 64 MB of memory, and pump-controlled conductivity time response. Real-time data can be transmitted via RS-232 simultaneous with data recording, The SBE 19plus V2 integrates easily with an SBE 32 Carousel Water Sampler or SBE 55 ECO Water Sampler for real-time or autonomous operation.
- The SBE 49 FastCAT is an integrated CTD sensor intended for towed vehicle, ROV, AUV, or other autonomous profiling applications. Real-time data ‑ in raw format or in engineering units ‑ is logged or telemetered by the vehicle to which it is mounted. The SBE 49’s pump-controlled, TC-ducted flow minimizes salinity spiking, and its 16 Hz sampling provides very high spatial resolution of oceanographic structures and gradients. The SBE 49 has no memory or internal batteries. The SBE 49 integrates easily with an SBE 32 Carousel Water Sampler or SBE 55 ECO Water Sampler for real-time operation.
The specialized profiling CTD instruments are the SBE 52-MP Moored Profiler, Glider Payload CTD, and SBE 41/41CP Argo CTD module:
- The SBE 52-MP Moored Profiler is a conductivity, temperature, pressure sensor, designed for moored profiling applications in which the instrument makes vertical profile measurements from a device that travels vertically beneath a buoy, or from a buoyant sub-surface sensor package that is winched up and down from a bottom-mounted platform. The 52-MP's pump-controlled, TC-ducted flow minimizes salinity spiking. The 52-MP can optionally be configured with an SBE 43F dissolved oxygen sensor.
- The Glider Payload CTD measures conductivity, temperature, and pressure, and optionally, dissolved oxygen (with the modular SBE 43F DO sensor). It is a modular, low-power profiling instrument for autonomous gliders with the high accuracy necessary for research, inter-comparison with moored observatory sensors, updating circulation models, and leveraging data collection opportunities from operational vehicle missions. The pressure-proof module allows glider users to exchange CTDs (and DO sensors) in the field without opening the glider pressure hull.
- Argo floats are neutrally buoyant at depth, where they are carried by currents until periodically increasing their displacement and slowing rising to the surface. The SBE 41/41CP CTD Module obtains the latest CTD profile each time the Argo float surfaces. At the surface, the float transmits in-situ measurements and drift track data to the ARGOS satellite system. The SBE 41/41CP can be integrated with Sea-Bird's Navis float, Navis float with Biogeochemical Sensors, or floats from other manufacturers. The SBE 41N CTD is integrated with Sea-Bird's Navis Float with Integrated Biogeochemical Sensors.
See Product Selection Guide for a table summarizing the features of our profiling CTDs.
What do I need to send to Sea-Bird for calibration of my SBE 9plus, 25, or 25plus?
For calibration of the temperature and conductivity sensors, only the sensor modules need to be sent to Sea-Bird. It is not necessary to send the CTD main housing. See Shipping SBE 9plus, 25, and 25plus Temperature and Conductivity Sensors for details.
It is usually not necessary to recalibrate the pressure sensor as frequently as the temperature and conductivity sensors. Experience has shown that the sensor’s sensitivity function almost never changes; only the offset drifts. The offset drift can easily be measured by reading deck pressure against a barometer. This small drift is easily corrected (Seasave V7 and SBE Data Processing provide an entry for the offset drift in the instrument .con or .xmlcon file).
- SBE 9plus and 25plus — If the pressure sensor does need to be calibrated, the entire CTD must be shipped to Sea-Bird.
- SBE 25 — If the pressure sensor does need to be calibrated, only the modular SBE 29 pressure sensor needs to be sent to Sea-Bird. It is not necessary to send the CTD main housing.
How should I pick the pressure sensor range for my CTD? Would the highest range give me the most flexibility in using the CTD?
While the highest range does give you the most flexibility in using the CTD, it is at the expense of accuracy and resolution. It is advantageous to use the lowest range pressure sensor compatible with your intended maximum operating depth, because accuracy and resolution are proportional to the pressure sensor's full scale range. For example, the SBE 9plus pressure sensor has initial accuracy of 0.015% of full scale, and resolution of 0.001% of full scale. Comparing a 2000 psia (1400 meter) and 6000 psia (4200 meter) pressure sensor:
- 1400 meter pressure sensor ‑ initial accuracy is 0.21 meters and resolution is 0.014 meters
- 4200 meter pressure sensor ‑ initial accuracy is 0.63 meters and resolution is 0.042 meters
What are the major steps involved in taking a cast with a Profiling CTD?
Following is a brief outline of the major steps involved in taking a CTD cast, based on generally accepted practices. However, each ship, crew, and resident technicians have their own operating procedures. Each scientific group has their own goals. Therefore, observe local ship and scientific procedures, particularly in areas of safety. Before the cruise a discussion of the planned work is advisable between the ship’s crew, resident technicians, and scientific party. At this time discuss and clarify any specific ship’s procedures.
Note: The following procedure was written for an SBE 9plus CTD operating with an SBE 11plus Deck Unit. Modify the procedure as necessary for your CTD.
10 to 15 minutes before Station:
- Review the next cast’s plan, including proposed maximum cast depth, bottom depth, and number of bottles to close and depths. If the cast will be close to the bottom, familiarize yourself with the bottom topography.
- Verify that all water samples have been obtained from the bottles from the previous cast. If so, drain the bottles and cock them. Hand manipulate each Carousel latch as you cock the bottle to ensure it is free to release and is not stuck in some way.
- Remove the soaker tubes from the conductivity cells.
- Remove any other sensor covers.
- With permission from the deck crew, power up the CTD. Check the Deck Unit front panel display to verify communication. Perform a quick frequency check of the main sensors.
- Start Seasave. Set up a fixed display. Select Do not archive data for this cast. Start acquisition and view the data to verify the system is operational.
- Clean optical sensor windows, and perform any required air calibration.
- Stop acquisition. Do Not turn the CTD Deck Unit off. Select begin archiving data immediately. Set up the plot scales and status line.
5 minutes before Station:
- Start the ship's depth sounder and obtain a good depth reading. Be careful reading the depth sounder; if it is improperly configured the trace will wrap around the plot and be incorrect. The bottom depth should be close to the expected charted depth.
- Fill out any parts of the cast log that can be done at this time.
On Station, On Deck:
- Verify the position and the bottom depth.
- The computer operator should begin filling out the software header.
- After receiving word from the bridge that they are on station and ready to begin, untie the CTD and move it into position. If this requires hydraulics, ensure you have the appropriate people in place and permission.
- Position the CTD under the block. Have the winchman remove any slack from the wire.
- Notify the computer room that the CTD is ready for launch. The computer room should start acquiring data.
- Obtain a barometric pressure reading and note it on the cast sheet.
- When the bridge, computer room, and winchman are ready (and you have permission to proceed), put the CTD in the water.
- Have the winchman lower the CTD to 10 meters (his readout), hold for 1 minute, and then bring it back to the surface. One operator should remain on deck to help the winchman see when to stop the CTD. The CTD should be far enough below the surface so that the package does not break the surface in the swells.
CTD Soaking at the Surface:
- Finish filling out the cast log. Re-check the bottom depth.
- Fill out the computer software log.
- Hold the CTD at the surface for at least 3 minutes.
- Check the status line to verify that the CTD values are correct. The pressure should be the soaking depth of the CTD. Comparing the CTD temperature and salinity to the ship's thermosalinograph is helpful. Log the information (CTD and thermosalinograph) on the cast sheet.
Starting the Cast:
- Call the winchman and have him start the cast down. Typical lowering speed is 1 m/sec, modified for conditions as needed.
- Watch the computer output and verify that the system is working.
During the Cast:
- Closely monitor the CTD output for malfunctions. Sudden noise in a channel is often a sign of a leaking cable. A periodically flashing error light on the Deck Unit is a sign of a bad spot in the slip rings. The modulo error count (usually on the status line) provides an indication of telemetry integrity; on a properly functioning system, there will be no modulo errors.
- Note any odd behavior or problems on the cast sheet. Keeping good notes and records is of critical importance. While you may remember what happened an hour from now, in the months that follow, these notes will be a vital link to the cruise as you process the data.
- Monitor the bottom depth. This is especially critical if the cast will be close to the bottom, or you are working in an area with varying topography such as in a canyon. Running the CTD into the bottom can cause serious (and expensive) damage.
Approaching the Bottom:
- Take extra care if the cast will take the CTD close to the bottom. Monitor the bottom depth, pinger, and altimeter, if available. As you get within 30 meters of the bottom, slow down the cast to 0.5 m/sec. If you wish to get closer than 10 m above the bottom, slow down to 0.2 m/sec. Keep in mind that ship roll will cause the CTD depth to oscillate by several meters.
- If the CTD does touch bottom, it will be apparent from the sudden, low salinity spike. A transmissometer, if installed, will also show a sudden low spike.
- Adjust these numbers and procedures as conditions dictate to avoid crashing the CTD into the bottom.
- When the CTD reaches the maximum cast depth, call the winchman and stop the descent.
- Log a position on the cast sheet. If a bottle will be closed at the bottom, allow the CTD to soak for at least 1 minute (preferably several minutes) and then close the bottle. Verify that the software records the bottle closure confirmation.
- Start the CTD upcast. Stop the CTD ascent at any other bottle closure depths. For each bottle, soak for at least 1 minute (preferably several minutes) and then close the bottle.
End of the Cast:
- As the CTD approaches the surface, have someone help spot for the winchman. Stop the CTD below the surface. Close a bottle if desired.
- When ready, recover the CTD. Avoid banging the system against the ship.
CTD Back on Board:
- Stop data acquisition and power off the CTD.
- Move the CTD it into its holding area and secure it.
- See Application Note 2D: Instructions for Care and Cleaning of Conductivity Cells for details on rinsing, cleaning, and storing the conductivity cell. Fill the conductivity cell with clean DI (or 1% Triton-X) and secure the filler device to the CTD frame. Freezing water in a conductivity cell will break the cell.
- See Application Note 64: SBE 43 Dissolved Oxygen Sensor - Background Information, Deployment Recommendations, and Cleaning and Storage for details on rinsing, cleaning, and storing SBE 43 (membrane-type) dissolved oxygen sensors; see the SBE 63 manual for details on rinsing, cleaning, and storing SBE 63 optical dissolved oxygen sensors.
- Rinse any optical sensors.
- Rinse the water sampler latches with clean water.
- Draw water samples from the bottles.
After the Cast:
- Re-plot the data and look at any channels that were not displayed in real time.
- Perform diagnostics and take a first pass through processing.
- Verify that the data is good (at least on a first-order basis) at this point, when you can still re-do the cast. Many casts are lost because they are not analyzed until months later, when the problems are discovered.
- Final processing may need to wait until bottle salts and post-cruise lab calibrations are available.
I am ordering a CTD and want to use auxiliary sensors. Should I order them from Sea-Bird also, or deal directly with the sensors’ manufacturers?
This depends on your own expertise and resources. We have extensive experience in integrating and supporting a wide range of auxiliary sensors, but not everything under the sun. We have a large list of commonly used sensors that we routinely offer for sale (see Third Party Sensor Configuration).
When you purchase any of these auxiliary sensors from Sea-Bird, we are able to apply this experience to integrating the sensors with the CTD. The integration includes installing the sensors (with appropriate mounting kits and cables) in a manner that puts each sensor in the best possible orientation for optimum performance. It also includes configuring the CTD system and software to accept the sensors’ inputs and properly display the data, and testing the entire system, typically in a chilled saltwater bath overnight, to confirm proper operation. Having done the integration, we also support the entire system in terms of follow-on service and end-user support with operational and data analysis questions *. There is significant added value in our integration service, and there is some extra cost for this, compared to doing it yourself. However, we do not base our business on selling services, and the prices charged for Third Party sensors carry minimal mark-ups that vary depending on the pricing we are offered by the manufacturers. In some cases we can sell at the manufacturer's list price, and in others we have to add margin.
1. As described in our Warranty, auxiliary sensors manufactured by other companies are warranted only to the limit of the warranties provided by their original manufacturers (typically 1 year).
2. Click here for information on repairing / recalibrating auxiliary sensors manufactured by other companies.
Should I collect water samples (close bottles) on the downcast or the upcast?
Most of our CTD manuals refer to using downcast CTD data to characterize the profile. For typical configurations, downcast CTD data is preferable, because the CTD is oriented so that the intake is seeing new water before the rest of the package causes any mixing or has an effect on water temperature.
However, if you take water samples on the downcast, the pressure on an already closed bottle increases as you continue through the downcast; if there is a small leak, outside water is forced into the bottle, contaminating the sample with deeper water. Conversely, if you take water samples on the upcast, the pressure decreases on an already closed bottle as you bring the package up; any leaking results in water exiting the bottle, leaving the integrity of the sample intact. Therefore, standard practice is to monitor real-time downcast data to determine where to take water samples (locations with well-mixed water and/or with peaks in the parameters of interest), and then take water samples on upcast.
How often do I need to have my instrument and/or auxiliary sensors recalibrated? Can I recalibrate them myself?
- Profiling CTD — recalibrate once/year, but possibly less often if used only occasionally. We recommend that you return the CTD to Sea-Bird for recalibration. (In principle, it is possible for calibration to be performed elsewhere, if the calibration facility has the appropriate equipment andtraining. However, the necessary equipment is quite expensive to buy and maintain.) In between laboratory calibrations, take field salinity samples to document conductivity cell drift.
- Thermosalinograph — recalibrate at least once/year, but possibly more often depending on the degree of bio-fouling in the water.
- DO sensor —
— SBE 43 — recalibrate once/year, but possibly less often if used only occasionally and stored correctly (see Application Note 64), and also depending on the amount of fouling and your ability to do some simple validations (see Application Note 64-2)
— SBE 63 — recalibrate once/year, but possibly less often if used only occasionally and stored correctly and also depending on the amount of fouling and your ability to do some simple validations (see SBE 63 manual)
- pH sensor — recalibrate every 6 months
- Transmissometer — usually do not require recalibration for several years. Recalibration at the manufacturer’s factory is the most practical method.
We often have requests from customers to have some way to know if the CTD is out of calibration. The general character of sensor drift in Sea-Bird conductivity, temperature, and pressure measurements is well known and predictable. However, it is very difficult to know precisely how far a CTD calibration has drifted over time unless you have access to a very sophisticated calibration lab. In our experience, an annual calibration schedule will usually maintain the CTD accuracy to within 0.01 psu in Salinity.
Conductivity drifts as a change in slope as a result of accumulated fouling that coats the inside of the conductivity cell, reducing the area of the cell and causing an under-reporting of conductivity. Fouling consists of both biological growth and accumulated oils and inorganic material (sediment). Approximately 95% of fouling occurs as the cell passes through oil and other contaminants floating on the sea surface. Most conductivity fouling is episodic, as opposed to gradual and steady drift. Most fouling events are small and mostly transitory, but they have a cumulative affect over time. A severe fouling event, such as deployment through an oil spill, could have a dramatic but only partially recoverable effect, causing an immediate jump shift toward lower salinity. As fouling becomes more severe, the fit becomes increasingly non-linear and offsets and slopes no longer produce adequate correction, and return to Sea-Bird for factory calibration is required. Frequently checking conductivity drift is likely to be the most productive data assurance measure you can take. Comparing conductivity from profile to profile (as a routine check) will allow you to detect sudden changes that may indicate a fouling event and the need for cleaning and/or re-calibration.
Temperature generally drifts slowly, at a steady rate and predictably as a simple offset at the rate of about 1-2 millidegrees per year. This is approximately equal to 1-2 parts per million in Salinity error (very small).
Pressure sensor drift is also an offset, and annual comparisons to an accurate barometer to determine offset will generally keep the sensor within specification for several years, particularly as the sensors age over time.
Can I deploy my profiling CTD for monitoring an oil spill?
Sea-Bird CTDs can be deployed in oil; the oil will not cause long-term damage to the CTD. If the oil coats the inside of the conductivity cell and coats the dissolved oxygen sensor membrane, it can possibly affect the sensor’s calibration (and thus affect the measurement and the data). Simple measures can reduce the impact, as follows:
- To minimize the ingestion of oil into the conductivity cell and onto the DO sensor membrane:
SBE 19, 19plus, 19plus V2, 25, or 25plus CTD:
Set up the CTD so that the pump does not turn on until the CTD is in the water and below the layer of surface oil, minimizing ingestion of oil (however, some oil will still enter the system). Pump turn-on is controlled by two user-programmable parameters: the minimum conductivity frequency and the pump delay.
Set the minimum conductivity frequency for pump turn-on above the instrument’s zero conductivity raw frequency (shown on the conductivity sensor Calibration Sheet), to prevent the pump from turning on when the CTD is in air. Note that this is the same as our typical recommendation for setting the minimum conductivity frequency.
For salt water and estuarine applications - typical value = zero conductivity raw frequency + 500 Hz
For fresh/nearly fresh water - typical value = zero conductivity raw frequency + 5 Hz
If the minimum conductivity frequency is too close to the zero conductivity raw frequency, the pump may turn on when the CTD is in air as result of small drifts in the electronics. Another option is to rely only on the pump turn-on delay time to control the pump; if so, set a minimum conductivity frequency lower than the zero conductivity raw frequency.
Set the pump turn-on delay time to allow enough time for you to lower the CTD below the surface oil layer after the CTD is in the water (the CTD starts counting the pump delay time after the minimum conductivity frequency is exceeded). You may need to set the pump delay time to be longer than our typical 30-60 second recommendation.
The current minimum conductivity frequency and pump delay can be checked by sending the status command to the CTD (DS or GetCD, as applicable). Commands for modifying these parameters are:
- SBE 19: SP (SBE 19 responds with prompts for setting up these parameters)
- SBE 19plus and 19plus V2: MinCondFreq=x and PumpDelay=x (where x is the value you are programming).
- SBE 25: CC (SBE 25 responds with a series of setup prompts, including setting up these parameters)
- SBE 25plus: SetMinCondFreq=x and SetPumpDelay=x (where x is the value you are programming).
SBE 9plus CTD:
Minimum conductivity frequency and pump delay are not user-programmable for the 9plus.
If you are using your 9plus with the 11plus Deck Unit, the Deck Unit provides power to the 9plus. Without power, the pump will not turn on. At the start of the deployment, to ensure that you have cleared the surface oil layer before the pump turns on, do not turn on the Deck Unit until the 9plus is below the surface oil layer. Similarly, on the upcast, turn off the Deck Unit before the 9plus reaches the surface oil layer.
If your 9plus is equipped with the optional manual pump control, you can enable manual pump control via the Pump Control tab in Seasave V7’s Configure Inputs dialog box. Once enabled, you can turn the pump on and off from Seasave V7’s Real-Time Control menu. Do not turn the pump on until the CTD is below the surface oil layer. On the upcast, turn the pump off before the CTD reaches the surface oil layer.
- To reduce the effect of the ingestion of oil into the conductivity cell and onto the DO sensor membrane or optical window:
After each recovery, rigorously follow the cleaning and storage procedures in the following application notes ‑
- Application Note 2D: Instructions for Care and Cleaning of Conductivity Cells
- Application Note 64: SBE 43 Dissolved Oxygen Sensor – Background Information, Deployment Recommendations, and Cleaning and Storage
- SBE 63 Optical Dissolved Oxygen Sensor manual
Quick Reference Sheets for Oil Spill Deployment:
I want to add an auxiliary sensor to my CTD (SBE 9plus, 16, 16plus, 16plus-IM, 16plus V2, 16plus-IM V2, 19, 19plus, 19plus V2, 21, 25, or 25plus). Assuming the auxiliary sensor is compatible with the instrument, what is the procedure?
Adding the sensor(s) is reasonably straightforward:
- Mount the sensor; a poor mounting scheme can result in poor data.
Note: If the new sensor will be part of a pumped system, the existing plumbing must be modified; consult Sea-Bird for details.
- Attach the new cable.
- (not applicable to 9plus used with 11plus Deck Unit) Using the appropriate terminal program — Enable the channel(s) in the CTD, using the appropriate instrument command.
- Using Seasave V7 or SBE Data Processing — Modify the CTD configuration (.con or .xmlcon) file to reflect the new sensor, and type in the calibration coefficients.
What are the recommended practices for connectors - mating and unmating, cleaning corrosion, and replacing?
Mating and Unmating Connectors:
It is important to prepare and mate connectors correctly, both in terms of the costs to repair them and to preserve data quality. Leaking connectors cause noisy data and even potential system shutdowns. Application Note 57: Connector Care and Cable Installation describes the proper care and installation of connectors for Sea-Bird instruments. The Application Note covers connector cleaning and cable or dummy plug installation, locking sleeve installation, and cold weather tips.
Checking for Leakage and Cleaning Corrosion on Connectors:
If there has been leakage, it will show up as green-colored corrosion product. Performing the following steps can usually reverse the effect of the leak:
- Thoroughly clean the connector with water, followed by alcohol.
- Give the connector surfaces a light coating of silicon grease.
Re-mate the connectors properly — see Application Note 57: Connector Care and Cable Installation and 9-minute video covering O-ring, connector, and cable maintenance.
- The main concern when replacing a bulkhead connector is that the o-rings on the connector and end cap must be prepared and installed correctly; if they are not, the instrument will flood. See the question below for general procedure on handling o-rings.
- Use a thread-locking compound on the connector threads to prevent the new connector from loosening, which could also lead to flooding.
- If the cell guard must be removed to open the instrument, take extra care not to break the glass conductivity cell.
Do I need to clean the exterior of my instrument before shipping it to Sea-Bird for calibration?
Remove as much biological material and/or anti-foul coatings as possible before shipping. Sea-Bird cannot place an instrument with a large amount of biological material or anti-foul coating on the housing in our calibration bath; if we need to clean the exterior before calibration, we will charge you for this service.
- To remove barnacles, plug the ends of the conductivity cell to prevent the cleaning solution from getting into the cell. Then soak the entire instrument in white vinegar for a few minutes. After scraping off the barnacles and marine growth, rinse the instrument well with fresh water.
- To remove anti-foul paint, use a Heavy Duty Scotch-Brite pad (http://www.3m.com/us/home_leisure/scotchbrite/products/scrubbing_scouring.html) or similar scrubbing device.
What are the recommended practices for storing sensors at low temperatures, and deploying at low temperatures or in frazil or pancake ice?
Large numbers of Sea-Bird conductivity instruments have been used in Arctic and Antarctic programs.
Special accommodation to keep temperature, conductivity, oxygen, and optical sensors at or above 0 C is advised. Often, the CTD is brought inside protective doors between casts to achieve this.
When freezing is possible, we recommend that the conductivity sensor be stored dry. Remove larger droplets of water by blowing through the cell. Do not use compressed air, which typically contains oil vapor. Attach a length of Tygon tubing to each end of the conductivity cell to close the cell ends. See Application Note 2D: Instructions for Care and Cleaning of Conductivity Cells for details.
There are several considerations to weigh when contemplating deployments at low temperatures in general, and in frazil or pancake ice:
- Ensure that the instrument is at or above water temperature before it is deployed. If the cell gets colder than 0 to -2 ºC while on deck, when it enters the water a layer of ice forms inside the cell as the cell warms to ocean temperature. If ice forms inside the conductivity cell, measurements will be low of correct until the ice layer melts and disappears. Thin layers of ice will not hurt the conductivity cell, but repeated ice formation on the electrodes will degrade the conductivity calibration (at levels of 0.001 to 0.020 psu) and thicker layers of ice can lead to glass fracture and permanent damage of the cell.
- For accurate measurements, keep ice out of the sensing region of the conductivity cell. The conductivity measurement involves determining the electrical resistance of the water inside the sensor. Ice is essentially a non-conductor. To the extent that ice displaces the water, the conductivity will register (very) misleadingly low. Some type of screening is necessary to keep ice out of the cell. This is relatively easy to arrange for the Sea-Bird conductivity cell, which is an electrode-type cell, because its sensing region is totally inside a long tube; plastic mesh could be positioned at each end and would have zero effect on accuracy and stability.
The above considerations apply to all known conductivity sensor types, whether electrode or inductive types.
If deploying at low temperatures but no surface frazil or pancake ice is present, rinse the conductivity cell in one of the following salty solutions (salty water depresses the freezing point) to prevent freezing during deployment. But this does not mean you can store the cell in one of these solutions outside . . . it will freeze.
- Solution of 1% Triton in sterile seawater (use 0.5-micron filtered seawater or boiled seawater), or
- Brine solution (distilled seawater or homemade salt solution that is higher than 35 psu in salinity).
Note that there is still a risk of forming ice inside the conductivity cell if deploying through frazil or pancake ice on the surface, if the freezing point of the salt water is the same as the water temperature. Therefore, we recommend that you deploy the conductivity cell in a dry state for these deployments.
Commercially available alcohol or glycol antifreezes contain trace amounts of oils that will coat the conductivity cell and the electrodes, causing a calibration shift, and consequently result in errors in the data. Do not use alcohol or glycol in the conductivity cell.
In general, neither the accuracy of the temperature measurement nor the survival of the temperature sensor will be affected by ice.
For the SBE 43 and SBE 63 Dissolved Oxygen sensor, avoid prolonged exposure to freezing temperature, including during shipment. Do not store the with water (fresh or seawater), Triton solution, alcohol, or glycol in the plenum. The best precaution is to keep the sensor indoors or in some shelter out of the cold weather.
I want to change the pressure sensor on my CTD, swapping it as needed to get the best data for a given deployment depth. Can I do this myself, or do I need to send the instrument to Sea-Bird?
On most of our instruments, replacement of the pressure sensor should be performed at Sea-Bird. We cannot extend warranty coverage if you replace the pressure sensor yourself.
However, we recognize that you might decide to go ahead and do it yourself because of scheduling/cost issues. Some guidelines follow:
- Perform the swap and carefully store the loose sensor on shore in a laboratory or electronics shop environment, not on a ship. The pressure sensor is fairly sensitive to shock, and a loose sensor needs to be stored carefully. Dropping the sensor will break it.
- Some soldering and unsoldering is required. Verify that the pressure sensor is mounted properly in your instrument. Properly re-grease and install the o-rings, or the instrument will flood.
- Once the sensor is installed, back-fill it with oil. Sea-Bird uses a vacuum-back filling apparatus that makes this job fairly easy. We can provide a drawing showing the general design of the apparatus, which can be modified and constructed by your engineers.
- For the most demanding work, calibrate the sensor on a deadweight tester to ensure proper operation and calibration.
- Enter the calibration coefficients for the new sensor in:
- the CTD configuration (.con or .xmlcon) file, using Seasave V7 or SBE Data Processing, and
- (for an instrument with internally stored calibration coefficients) the CTD EEPROM, using the appropriate terminal program and the appropriate calibration coefficient commands
Note: This discussion does not apply to the SBE 25 (not 25plus), which uses a modular pressure sensor (SBE 29) mounted externally on the CTD. Swap the SBE 29 as desired, use the CC command in Seaterm or SeatermAF to enter the new pressure range and pressure temperature compensation value, and type the calibration coefficients for the new sensor into the CTD configuration (.con or .xmlcon) file in Seasave V7 or SBE Data Processing.
How many/what kind of spares should I have on ship for my SBE 9plus?
The most complete backup system would be another SBE 9plus, to allow for very rapid system swaps. This is important if your stations are close together and there is limited time between CTD casts. However, it is the most expensive option.
The next step down would be an SBE 9plus without sensors. In this case, a system failure would require swapping sensors and pumps to the new unit. This is not difficult, but it is somewhat time consuming. If you have several hours between casts it should not be a problem.
The next option would be to carry spare boards and try and troubleshoot the problem and replace boards. If you have a technician that can do this it is not a bad option. However, it requires some clean and dry lab space to open the CTD and work. You will also have to properly re-seal the CTD. Based upon experience, the SBE 9plus does not fail very often. The most common failure is the main DC-to-DC converter. Other than that, there are very few system failures. However, there are several components that can be damaged through mistakes or misuse. The most catastrophic, other that losing the whole CTD, is to plug the sea cable into the bottom contact connector on the bottom end cap; if this happens, several circuit boards will be destroyed (Note: In 2007 Sea-Bird began using a female bulkhead connector on the 9plus for the bottom contact switch, to differentiate from the sea cable connector and prevent this error. If desired, older CTDs can be retrofitted with the female connector.).
If the budget allows it, we recommend getting a complete backup SBE 9plus, including sensors. If there is any problem, return the malfunctioning instrument for repair and continue sampling with the spare instrument. A complete backup also provides you with spare sensors, so you can rotate 1 set through calibration and continue to operate.
Can I brush-clean and replatinize the conductivity cell myself? How often should this be done?
Brush-cleaning and replatinizing should be performed at Sea-Bird. We cannot extend warranty coverage if you perform this work yourself.
The brush-cleaning and replatinizing process requires specialized equipment and chemicals, and the disassembly of the sensor. If performed incorrectly, you can damage the cell. Additionally, the sensor must be re-calibrated when the work is complete.
Sea-Bird determines whether brush-cleaning and replatinizing is required based upon how far the calibration has drifted from the original calibration. Typically, a conductivity sensor on a profiling CTD requires brush-cleaning and replatinizing every 5 years.
Is it necessary to put my instrument in water to test it? Will I destroy the conductivity cell if I test it in air?
It is not necessary to put the instrument in water to test it. It will not hurt the conductivity cell to be in air.
If there is a pump on the instrument, it should not be run for extended periods in air.
- Profiling instruments (SBE 9plus, 19, 19plus, 19plus V2, 25, 25plus, 49) and some moored instruments (all pumped MicroCATs with integral dissolved oxygen (DO), and pumped MicroCATs without DO with firmware 3.0 and later) do not turn on the pump unless the conductivity frequency is above a specified minimum value (minimum value is hard-wired in 9plus, user-programmable in other instruments). This prevents the pump from turning on in air. See the instrument manual for details.
- If your instrument does not check for conductivity frequency before turning on the pump:
- For moored SeaCATs (16, 16plus, 16plus-IM, 16plus V2, 16plus-IM V2): Disconnect the pump cable for the test.
- For older pumped MicroCATs: orient the MicroCAT to provide an upright U-shape for the plumbing. Then fill the inside of the pump head with water via the pump exhaust tubing; this will provide enough lubrication to prevent pump damage during brief testing.
An SBE 911plus order requires ordering the SBE 9plus CTD underwater unit as well as the SBE 11plus Deck Unit, shown in separate sections below. Alternatively, if using the SBE 9plus autonomously, an SBE 11plus Deck Unit is not required; order the SBE 17plus instead.
|9plus||UNDERWATER UNIT for 911plus CTD - 24 Hz sampling rate, includes modular Temperature & Conductivity sensors with TC Duct, SBE 5T submersible pump, redundant T & C input channels, 8 differential input, low pass-filtered A/D channels, water sampler modem channel, stainless steel guard cage, seacable pigtail, Seasoft software, & complete documentation. Specify: housing/connector & pressure sensor range (depth limit) selections.||
Real-Time Data Operation:
|SBE 9plus Housing and Connector Selections — MUST SELECT ONE|
|9p-1a||Aluminum housing, 6800 m depth rating (XSG/AG connectors)||9plus is available for maximum depths of 6800 m (aluminum housing for main housing & T & C sensors) or 10,500 m (titanium housing for main housing & T & C sensors). SBE 5T pump is titanium, regardless of housing option, & is rated for 10,500 m.
These options include XSG/AG or wet-pluggable bulkhead connectors. Wet-pluggable connectors may be mated in wet conditions. Their pins do not need to be dried before mating. By design, water on connector pins is forced out as connector is mated. However, they must not be mated or un-mated while submerged. Wet-pluggable connectors have a non-conducting guide pin to assist pin alignment & require less force to mate, making them easier to mate reliably under dark or cold conditions, compared to XSG/AG connectors. Like XSG/AG connectors, wet-pluggables need proper lubrication & require care during use to avoid trapping water in sockets.
|9p-1b||Aluminum housing, 6800 m depth rating with Wet-pluggable connectors on CTD, T&C sensors, pump, & related cables|
|9p-1c||Titanium housing, 10,500 m depth rating (XSG/AG connectors)|
|9p-1d||Titanium housing, 10,500 m depth rating with Wet-pluggable connectors on CTD, T&C sensors, pump, & related cables|
|SBE 9plus Pressure Sensor Range (depth) Selections — MUST SELECT ONE|
|9p-2a||0 - 2000 psia (1400 m) pressure sensor||Pressure sensor is installed in main housing bottom end cap. Unlike modular T & C sensors, pressure sensor is not field-replaceable / swappable. While highest pressure rating gives you most flexibility in using 9plus, it is at expense of accuracy & resolution. It is advantageous to use lowest range pressure sensor compatible with your intended maximum operating depth, because accuracy & resolution are proportional to pressure sensor's full scale range. For example, comparing 1400 & 4200 m sensors:
|9p-2b||0 - 3000 psia (2000 m) pressure sensor|
|9p-2c||0 - 6000 psia (4200 m) pressure sensor|
|9p-2d||0 - 10,000 psia (6800 m) pressure sensor|
|9p-2e||0 - 15,000 psia (10,500 m) pressure sensor|
|SBE 9plus Secondary Temperature and Conductivity Sensor Options|
|9p-3a||Secondary T & C sensors, aluminum housing, 6800 m, with TC Duct & Pump, XSG connectors||Secondary (redundant) T & C sensors can be used to verify data from primary T & C sensors, for applications requiring very high accuracy. Secondary sensors come complete with TC Duct & secondary pump (& all associated plumbing), & mount onto main housing bottom end cap like primary sensors. Secondary sensors are available for maximum depths of 6800 m (aluminum housing on T & C sensors) or 10,500 m (titanium housing on T & C sensors). 9plus is compatible with secondary T & C sensors; secondary sensors can be added to system in field without any modification to 9plus electronics.
Secondary sensor connector type (XSG/AG or wet-pluggable) must match 9plus connector type.
All 9p-3 options include SBE 3plus temperature sensor, SBE 4C conductivity sensor, SBE 5T pump, & associated cabling, plumbing, & mounting. Note that secondary pump is powered via same bulkhead connector as primary pump, via Y-cable included with all 9p-3 options (DN 31522 for standard connectors, DN 32673 for wet-pluggable connectors).
|9p-3b||Secondary T & C sensors, aluminum housing, 6800 m, with TC Duct & Pump, Wet-pluggable connectors (requires 9p-1b)|
|9p-3c||Secondary T & C sensors, titanium housing, 10,500 m, with TC Duct & Pump, XSG connectors|
|9p-3d||Secondary T & C sensors, titanium housing, 10,500 m, with TC Duct & Pump, Wet-pluggable connectors (requires 9p-1d)|
|SBE 9plus Command/Control and Data Telemetry Options|
|9p-4a||DELETE 300 baud modem module for water sampler control (CREDIT)||With standard water sampler modem in 9plus & 11plus, system provides real-time control for SBE 32 or 32C Carousel Water Sampler or G.O. 1016 water sampler.
Water sampler modem not required:
|9p-4b||Control module for GO 1015 water sampler, includes interface cables (requires water sampler modem)||With standard water sampler modem in 9plus & 11plus, & 9p-4b in 9plus, system provides real-time control for G.O. 1015 Rosette water sampler.|
|9p-4c||Optional RS-232 serial output interface, installed in place of 1015 interface. 9plus data output duplicates output from SBE 11plus deck unit, except that averaging and alignment must be done in post processing. This is a custom option for AUV integration applications. A PC running Seasave will be able to display and archive CTD data directly from 9plus – no deck unit required.||This option is typically desired when an AUV / ROV is logging 9plus data. When 9p-4c is ordered, PCB for G.O. 1015 is replaced with PCB for RS-232 serial output. 9plus transmits serial data through 3-pin JT4 connector on 9plus top end cap at 19,200 baud, 8 data bits, no parity. Power can also be supplied to 9plus through JT4 connector.|
|SBE 9plus Pump Control Options (typically used for fresh water applications)|
|9p-5a||Manual pump control allows user to turn pump on and off by command from Seasave software||Pump control commands are sent via Seasave V7 through SBE 11plus Deck Unit's Modem Channel connector, but pump control does not interfere with water sampler operation. Manual pump control is enabled/disabled on Pump Control tab in Seasave V7's Configure Inputs dialog box. Pump is turned on and off from Seasave V7's Real-Time Control menu. Note that you must remember to turn pump on; it will not turn on automatically if this option is installed.|
|9p-5b||Water contact pump control connector allows pump to automatically turn on 60 seconds after contact pin is immersed in water (salt or fresh), and automatically turn off when contact pin is removed from water (prevents use of bottom contact switch)||With this feature, pump control is independent of water conductivity. Contact pin is on a special dummy plug that connects to JB6 on 9plus bottom end cap. Modifications to 9plus internal wiring to JB6 for this option prevent use of JB6 for a bottom contact switch. Note that you must inspect contact pin periodically for corrosion; corrosion may prevent pump from turning on.|
|SBE 9plus Auxiliary Sensor Options|
|9p-6a||SBE 43 Dissolved Oxygen sensor (Profiling Configuration), 7000 m (XSG/AG connectors). Cable & mount included. (requires 9p-1a or 1c)||General Information:
|9p-6b||SBE 43 Dissolved Oxygen sensor (Profiling Configuration), 7000 m (Wet-pluggable connectors). Cable & mount included. (requires 9p-1b or 1d)|
|9p-6c||SBE 43 Dissolved Oxygen sensor (Profiling Configuration), 600 m plastic housing (XSG/AG connectors). Cable & mount included. (requires 9p-1a or 1c)|
|9p-6d||SBE 43 Dissolved Oxygen sensor (Profiling Configuration), 600 m plastic housing (Wet-pluggable connectors). Cable & mount included. (requires 9p-1b or 1d)|
|9p-7a||SBE 18 pH sensor, 1200 m (XSG/AG connectors). Cable & mount included. (requires 9p-1a or 1c)|
|9p-7b||SBE 18 pH sensor, 1200 m (Wet-pluggable connectors). Cable & mount included. (requires 9p-1b or 1d)|
|9p-8a||SBE 27 pH/ORP sensor, 1200 m (XSG/AG connectors). Cable & mount included. (requires 9p-1a or 1c)|
|9p-8a||SBE 27 pH/ORP sensor, 1200 m (Wet-pluggable connectors). Cable & mount included. (requires 9p-1b or 1d)|
|YMOLD||Extra charge for Y-cable to connect two (2) or more sensors to one (1) auxiliary sensor input bulkhead connector on CTD|
|9p-9a||Bottom Contact Switch module (XSG connector, cable & mount included) (requires 9p-1a or 1c)||Weight is attached with heavy line to switch. Switch closes when weight removed, setting bit in 9plus data stream. This causes alarm to turn on in 11plus Deck Unit, providing early warning that CTD is nearing ocean floor. Bottom contact switch does not use one of 8 A/D channels, so system can accommodate switch in addition to 8 auxiliary sensors.
Bottom contact switch connector type (XSG or wet-pluggable) must match 9plus connector type.
Note: Since 2007, Sea-Bird uses a female bulkhead connector on 9plus for bottom contact switch, in place of male bulkhead connector. This change was made to differentiate bottom contact switch connector from sea cable connector. See bottom end cap photo above & Application Note 86.
|9p-9b||Bottom Contact Switch module (Wet-pluggable connector, cable & mount included) (requires 9p-1b or 1d)|
|9p-11a||Serial Data Uplink, 9600 unidirectional RS-232, with 9600 baud sensor communication interface (requires water sampler modem channel, limits cable length to 8,000 m, prevents GO 1015 interface, & makes 9plus incompatible with SBE 17plus Searam & other 911plus CTDs that do NOT have this option)||300 baud modem for water sampler control (see note) is required to support serial data uplink. Serial data is multiplexed into 9plus telemetry stream & de-multiplexed by 11plus, outputting to computer through standard 9600 Baud Uplink connector. System supports use of serial data output instrument & water sampler in same cast.
If 9p-11b (19200 baud) selected, continuous transmission rate may not exceed 9600 baud (960 bytes/second). Therefore, serial data output instrument must transmit at 19200 baud in burst mode (transmissions separated by intervals with no data transmission, resulting in average rate of 960 bytes/second).
When 9p-11a or 11b is ordered, 3-pin JT4 connector for G.O. 1015 on 9plus top end cap is replaced with 4-pin serial data connector.
*Note: 300 baud modem in 9plus & 11plus has been standard since 2005. For older instruments, it was optional.
|9p-11b||Serial Data Uplink, 9600 unidirectional RS-232, with 19200 baud sensor communication interface (requires water sampler modem channel, limits cable length to 8,000 m, prevents GO 1015 interface, & makes 9plus incompatible with SBE 17plus Searam & other 911plus CTDs that do NOT have this option)|
|SBE 9plus Wide Range Calibration Options|
|9p-12a||Wide Range Calibration - Primary T & C (+45 degrees C & 9 S/m)||Standard calibration range goes up to +32.5 °C & 6 S/m; more than 99% of oceanographic work is below this temperature & conductivity. Our calibration equations & fits permit extrapolations significantly beyond this range with only minor loss of accuracy. Wide range calibration goes up to +45 °C (additional calibration points at 36, 40, & 45 °C) & 9 S/m. See Application Note 94: Wide-Range Conductivity Calibration.
Wide range calibrations require a 12-week lead time.
|9p-12b||Wide Range Calibration - Secondary T & C (requires option 9p-12a)|
|SBE 9plus Hardig Shipping Case Option|
|9p-13||Hardigg shipping case (AL4915-1105) instead of wood crate||Hardigg shipping case with custom foam inserts holds SBE 9plus with auxiliary sensors in standard cage.
Notes regarding features of Hardigg case supplied by Sea-Bird:
1. Case does not have wheels, because we prefer that the case is not rolled along the ground:
- Rolling along the ground could cause unnecessary vibration of the CTD.
- Rolling over a curb could cause unnecessary impact to the CTD.
2. Case has small holes on each metal latch, into which you could insert a small, TSA-approved lock or some zip ties. Case cannot accommodate a large padlock.
|SBE 9plus Spares & Accessories|
|32000||Technical Manual (spare), SBE 911plus CTD system||9plus CTD manual & 11plus Deck Unit manual customized for your application & including instrument configuration, calibration sheets, & schematics specific to your instrument. Note that electronic version of customized manuals are available on CD-ROM that accompanies shipment; see Documents tab for generic manuals.|
|50088||Seaspares (for Aluminum housing with XSG/AG connectors), SBE 9Plus support kit containing spare sensor cables, connectors, hardware, o-rings, clamps, tubing, fittings, anodes, etc.||Order appropriate Seaspares kit for housing type & connector type on 9plus:
|50139||Seaspares (for Titanium housing with XSG/AG connectors), SBE 9Plus support kit containing spare sensor cables, connectors, hardware, O-rings, clamps, tubing, fittings, etc.|
|50321||Seaspares (for Aluminum housing with Wet-pluggable connectors), SBE 9Plus support kit containing spare sensor cables, connectors, hardware, O-rings, clamps, tubing, fittings, anodes, etc.|
|50322||Seaspares (for Titanium housing with Wet-pluggable connectors), SBE 9Plus support kit containing spare sensor cables, connectors, hardware, O-rings, clamps, tubing, fittings, etc.|
|17252||2-pin seacable extension, RMG connectors, 0.7 m (DN 30588)||Female end connects to JT1 on 9plus top end cap (connector type must match 9plus); male end connects to sea cable. Many users leave extension connected to 9plus, & make connection to sea cable at end of extension (instead of at end cap, which is crowded with a number of connectors & may be difficult to access).|
|17120||2-pin seacable extension, RMG connectors, 2 m (DN 30588)|
|171090||2-pin seacable extension, RMG connectors, 3 m (DN 30588)|
|171743||2-pin seacable extension, Wet-pluggable connectors, 2 m (DN 32763)|
|171744||2-pin seacable extension, Wet-pluggable connectors, 3 m (DN 32763)|
|17198||Interface cable, 9plus to 32, AG connectors, 2 m (DN 30568)||Connects 9plus to SBE 32 or 32C Carousel Water Sampler. Connector type (AG or wet-pluggable) must match 9plus & SBE 32 or 32C connector type. Note that interface cable & mounting hardware are included with Carousel if Carousel is ordered with CTD integration kit for 9plus.|
|171741||Interface cable, 9plus to 32, Wet-pluggable connectors, 2 m (DN 32758)|
|17086||SBE 3 (Temperature) or SBE 4 (Conductivity) interface cable, RMG connectors, 0.63 m (DN 30566)||Spare cable to connect 9plus to SBE 3plus or 4C. Connector type (RMG or wet-pluggable) must match 9plus & SBE 3plus or 4C connector type.|
|171669||SBE 3 (Temperature) or SBE 4 (Conductivity) interface cable, Wet-pluggable connectors, 0.7 m (DN 32671)|
|17133||Pump cable, RMG-2FS to RMG-2FS, 1.1 m (DN 30565)||Spare cable to connect 9plus to SBE 5T pump. Connector type (RMG or wet-pluggable) must match 9plus & SBE 5T connector type.|
|171503||Pump cable, Wet-pluggable connectors, MCIL-2FS to MCIL-2FS, 1.1 m (DN 32499)|
|41713||Sea cable interface assembly (replaces 80593)||Spare PCBs for 9plus. Contact Sea-Bird with serial number of your 9plus to verify correct part number for PCB. (Click here to see an example of where to find the serial number on your instrument.)|
|41799||9plus Modem Card (replaces 801017)|
|40540||Control module for model 1015 water sampler (replaces 80585)|
|40968||Analog interface card (replaces 80589)|
|41613||Logic card (replaces 80621)|
|80935||Modulo 12P card (substitute for PN 80640)|
|80609||AP counter card|
|801042||9plus Control, store - A/D card (substitute for 80590)|
|50025||Pressure sensor oil refill kit (document 67066)||Due to temperature and pressure cycling over long periods, it is normal for some oil to slowly leak out of pressure sensor external capillary tube. When oil is not visible or is receding inside translucent tube, or if fitting has been damaged, refill oil using this kit. See Application Note 12-1: Pressure Port Oil Refill Procedure & Nylon Capillary Fitting Replacement.|
|50087||Cell filler/storage device (Application Note 34)||For cleaning conductivity cell after each use & storing instrument between uses. See document 67043 & Application Note 2D: Instructions for Care and Cleaning of Conductivity Cells.|
|various||Plumbing spares||For air bleed valve & y-fitting, snap-on connector, & assorted sizes of Tygon tubing, see SBE 5T Configuration.|
|801283||SBE 9plus stainless steel protective cage (includes PN 23559C, mounting hardware, etc.)||Spare cage (cage DN 20287).|
|31634||Hardigg shipping case (AL4915-1105)||Hardigg shipping case with custom foam inserts holds SBE 9plus with auxiliary sensors in standard cage.
1. Case does not have wheels, because we prefer that the case is not rolled along the ground:
- Rolling along the ground could cause unnecessary vibration of the CTD.
- Rolling over a curb could cause unnecessary impact to the CTD.
2. Case has small holes on each metal latch, into which you could insert a small, TSA-approved lock or some zip ties. Case cannot accommodate a large padlock.
|11P||.||1 – 120 VAC||1 – XSG|
|2 - 240 VAC||2 – MCBH|
|3 - EU 240 VAC|
Example: 11P.12 is an SBE 11plus V2 with 120 VAC power input and text cable for CTD with MCBH. See table below for description of each selection:
|11plus V2||DECK UNIT for 911plus CTD - (Version 2) includes IEEE-488 and RS-232 interfaces, water sampler modem channel, NMEA 0183 GPS interface, A/D input channel for
Surface PAR reference sensor, ASCII serial data output port, CTD pressure signal output, audible bottom contact alarm, audio tape interface, 120/240 VAC (switchable) input power, AC power cord, 10 m CTD test cable, NMEA test cable, remote output cable, serial data cable, rack mount kit, Seasoft software, and complete documentation.
9plus provides real-time data when controlled with 11plus V2 Deck Unit. 11plus V2 provides power, decodes data stream, passes data to computer, & allows user control of water sampler.
|SBE 11plus Power Selections — MUST SELECT ONE|
|11P.3x||EU 240 VAC|
|SBE 11plus CTD Connector (for test cable) Selections — MUST SELECT ONE|
|11P.x1||For SBE 9plus with XSG/AG connectors||This defines the connector on the CTD end of the test cable.|
|11P.x2||For SBE 9plus with MCBH connectors|
|SBE 11plus Spares & Accessories|
11plus V2 Back Panel; many of remaining parts relate to connections to back panel
|31043||Hardigg Case, AL-2221-0604, White, air tight, breather valve, SS hardware||Hardigg shipping case holds SBE 11plus.|
|17556||Deck Unit signal input cable (from slip rings to Deck Unit), 10m (DN 31371)||Pigtail connects Sea Cable on 11plus V2 to slip rings.|
|17557||Deck Unit signal input cable (from slip rings to Deck Unit), 20m (DN 31371)|
|17841||Deck Unit signal input cable (from slip rings to Deck Unit), 30m (DN 31371)|
|17912||Deck Unit signal input cable (from slip rings to Deck Unit), 50m (DN 31371)|
|50086||2-pin connector, deck unit seacable input||Connects to Sea Cable on 11plus V2. Included with standard shipment; this is spare.|
|80915||Test cable, 11/33/36 deck unit to 9/32/PDIM, RMG connector, 10 m (DN 31314)||Connects Sea Cable on 11plus V2 to 9plus CTD for testing. Included with standard shipment; these are spares:
|801587||Test cable, 11/33/36 Deck Unit to 9/32/PDIM, Wet-pluggable connector, 10 m (DN 32695)|
|801422||NMEA Test Cable, DB-9S to MS3106A, SBE 11p/33/36/45, 1.8 m (DN 32786)||Connects NMEA Input on 11plus V2 to computer simulating NMEA input for testing 11plus V2 NMEA interface. Included with standard shipment; this is spare.
NMEA simulation program, NMEATest, is part of Seasoft software, & is installed when you install SBE Data Processing.
|801429||Remote Data Output Test Cable, DB-9S to MS3106A, 1.8 m (DN 32799)||Connects Remote Out on 11plus V2 to computer to set up Remote Output interface. Cable is included with standard shipment; this is spare.|
|171887||RS-232 serial cable, DB-9F to DB-9M, 3 m (171887)||Connects SBE 11 Interface (RS-232) or Modem Channel on 11plus V2 to computer COM ports. Two cables included with standard shipment; this is spare.|
|801367||Cable, QSR/QCR-2200 SPAR to Deck Unit, 15 m (DN 32704)||Connects Surface PAR Input on 11plus V2 to Surface PAR sensor.|
|801368||Cable, QSR/QCR-2200 SPAR to Deck Unit, 30 m (DN 32704)|
|171890||RS-232 serial data uplink cable, DB-9P to DB-9S, 3 m||Null modem cable connects computer to Serial Data Uplink on 11plus V2 back panel. See 171890 for pinouts.
300 baud modem for water sampler control (see note below) & either 9p-11a or 9p-11b is required to support serial data uplink. Serial data is multiplexed into 9plus telemetry stream & de-multiplexed by 11plus V2, outputting to computer through standard 9600 Baud Uplink connector. System supports use of serial data output instrument & water sampler in same cast.
If 9p-11b (19200 baud) selected, continuous transmission rate may not exceed 9600 baud (960 bytes/second). Therefore, serial data output instrument must transmit at 19200 baud in burst mode (transmissions separated by intervals with no data transmission, resulting in average rate of 960 bytes/second).
*Note: 300 baud modem in 9plus & 11plus has been standard since 2005. For older instruments, it was optional.
|17015||AC power cord (US Standard), 2 m||One of these (as applicable) as included with standard shipment; this is spare.|
|17824||AC power cord, European plug, 2 m|
|30017||SBE 11plus rack mounting kit (spare)||For mounting 11plus V2 in standard rack. Included with standard shipment; this is spare. See document 67059.|
|80673||11plus modem board|
|20033||Mallory SC628MN alarm buzzer||Alarm sounds based on data from bottom contact switch &/or altimeter connected to 9plus, &/or minimum/maximum user-input pressure values.|
|22002||Primary power supply (Power One HTAA-16W-A)|
|80811||NMEA interface board (V1 deck units only)|
|80040||LED display board||11plus V2 front panel provides numeric display of frequency & voltage data via thumbwheel switch & 8-digit LED readout.|
|80586||11plus sea cable power supply|
|19006||Thumbwheel switch||11plus V2 front panel provides numeric display of frequency & voltage data via thumbwheel switch & 8-digit LED readout.|
SBE 9plus —
- pigtail to seacable, part # varies depending on length (RMG connector), DN 30579
- pigtail to seacable, part # varies depending on length (Wet-pluggable connector), DN 32514
- seacable extension, part # varies depending on length (RMG connectors), DN 30588
- seacable extension, part # varies depending on length (Wet-pluggable connectors), DN 32763
- 17086 To SBE 3 or SBE 4 (RMG connectors), 0.64 m, DN 30566
- 171669 To SBE 3 or SBE 4 (Wet-pluggable connectors), 0.76 m, DN 32671
- 17133 To SBE 5T (RMG connectors), 1.12 m, DN 30565
- 171503 To SBE 5T (Wet-pluggable connectors), 1.12 m, DN 32499
- 17799 To SBE 5T (y-cable for dual pumps, RMG connectors), DN 31522
- 171671 To SBE 5T (y-cable for dual pumps, Wet-pluggable connectors), DN 32673
- 80591 To SBE 11plus (from XSG connector), 2.4 m, DN 31314
- 80915 To SBE 11plus (from XSG connector), 10 m, DN 31314
- 801363 To SBE 11plus (from Wet-pluggable connector), 2.4 m, DN 32695
- 17546 To SBE 13 (RMG/AG connectors), 1.27 m, DN 31331
- 17132 To SBE 17plus (AG connectors), 0.33 m, DN 30568
- 171796 To SBE 17plus (Wet-pluggable connectors), 0.33 m, DN 32758
- 17474 To SBE 18 (RMG/AG connectors), 0.76 m, DN 30918
- 17898 To SBE 27 (AG connectors), 0.76 m, DN 31749
- 17198 To SBE 32 (AG connectors), 2 m, DN 30568
- 171741 To SBE 32 (Wet-pluggable connectors), 2 m, DN 32758
- 171220 Y-cable (SBE 9plus/35 or 35RT/32) (AG connectors), DN 32208
- 171995 Y-cable (SBE 9plus/35 or 35RT/32), (Wet-pluggable connectors), DN 32963
- 171491 To SBE 43 (RMG/AG connectors), 0.76 m, DN 32496
- 172218 To SBE 43 (Wet-pluggable connectors), 0.76 m, DN 32654
- 17133 To Bottom Contact Switch (RMG connectors, male bulkhead connector on 9plus), 1.12 m, DN 30565
- 172267 To Bottom Contact Switch (RMG/VMG connectors, female bulkhead connector on 9plus), 1.12 m, DN 33200
- 172270 To Bottom Contact Switch (Wet-pluggable connectors, female bulkhead connector on 9plus), 1.12 m, DN 33201
- 171130 To Benthos/Datasonics PSA-916 (from AG connector), 1.8 m, DN 32075
- 17437 To Benthos/Datasonics PSA-900 (from AG connector), 1.8 m, DN 30864
- 17610 To Biospherical QSP-200L or QSP-2300L (fromAG connector), 2 m, DN 30701
- 17602 To Chelsea AquaTracka or AlphaTracka (from AG connector), 1.2 m, DN 31253
- 17361 To D&A OBS-3 (from AG connector), 0.76 m, DN 30954
- 172130 To D&A OBS-3+ (from AG connector), High & Low range, 1 m, DN 33080
- 172131 To D&A OBS-3+ (from Wet-pluggable connector), High & Low range, 1 m, DN 33081
- 172109 To D&A OBS-3+ (from AG connector), Low range (1X), 1 m, DN 33058
- 172111 To D&A OBS-3+ (from Wet-pluggable connector), Low range (1X), 1 m, DN 33060
- 172110 To D&A OBS-3+ (from AG connector), High range (4X), 1 m, DN 33059
- 172112 To D&A OBS-3+ (from Wet-pluggable connector), High range (4X), 1 m, DN 33061
- 17196 (reverse polarity) To G.O. 1015 Rosette (from 9plus XSG connector), 2.5 m, DN 30566
- 17533 (normal polarity) To G.O. 1015 Rosette (from 9plus XSG connector), 2.4 m, DN 31315
- 172215 To Satlantic SatPAR (from AG connector), 2 m, DN 32628
- 172214 To Satlantic SatPAR (from Wet-pluggable connector), 2 m, DN 32654
- 171099 To Seapoint fluorometer or turbidity meter (1X) (from AG connector), 1.1 m, DN 32073
- 171147 To Seapoint fluorometer or turbidity meter (3X/5X) (from AG connector), 1.1 m, DN 32101
- 172221 To Seapoint fluorometer or turbidity meter (10X/20X) (from AG connector), 1.1 m, DN 31933
- 171845 To Seapoint fluorometer or turbidity meter (30X/100X) (from AG connector), 1.1 m, DN 31924
- 171908 To Turner Cyclops-7 (1X) (from AG connector), 1.1 m, DN 32910
- 171907 To Turner Cyclops-7 (10X) (from AG connector), 1.1 m, DN 32909
- 171909 To Turner Cyclops-7 (100X) (from AG connector), 1.1 m, DN 32911
- 171418 To Turner SCUFA (from AG connector), 1.1 m, DN 32417
- 17876 To WET Labs C-Star or WETStar with old-style 4-pin connector (from AG connector), 1.1 m, DN 31725
- 171953 To WET Labs ECO-AFL, ECO-FL, C-Star, or WETStar with new-style 6-pin connector (from AG connector), 1.1 m, DN 32491
- 172437 To WET Labs ECO-AFL, ECO-FL, C-Star, or WETStar with new-style 6-pin connector (from Wet-pluggable connector), 1.1 m, DN 32853
- 171869 To WET Labs ECO-FL-NTUS or ECO-FL-NTU(RT) (from AG connector), 1.1 m, DN 32812
- 172285 To WET Labs ECO-FL-NTUS or ECO-FL-NTU(RT) (from 9plus Wet-pluggable connector), 1.1 m, DN 32846
SBE 11plus —
- To slip ring (from SBE 11 Sea Cable), part # varies depending on length, DN 31371
- 80591 To SBE 9plus (with XSG connector) (test cable) (from SBE 11 Sea Cable), 2.4 m, DN 31314
- 80915 To SBE 9plus (with XSG connector) (test cable) (from SBE 11 Sea Cable), 10 m, DN 31314
- 801363 To SBE 9plus (with Wet-pluggable connector) (test cable) (from SBE 11 Sea Cable), 2.4 m, DN 32695
- 171886 To computer COM port (from SBE 11 Interface [RS-232] or SBE 11 Modem Channel), 3 m — for older 25-pin connector on SBE 11plus V2
- 171887 To computer COM port (from SBE 11 Interface [RS-232] or SBE 11 Modem Channel), 3 m — for current 9-pin connector on SBE 11plus V2
- 17082 To computer COM port (from SBE 11 Interface [IEEE-488]) — for older 25-pin connector on SBE 11plus V2
- 801422 To NMEA simulation computer COM port (from SBE 11 NMEA Input), 1.8 m, DN 32786
- 801429 To computer COM port (from SBE 11 Remote Out, for setup), 1.8 m, DN 32799
- 801367 To Surface PAR QSR-2200 or QCR-2200 with Switchcraft connector (from SBE 11 Surface PAR Input), 15 m, DN 32704
- 80665 To Surface PAR QSR-240 or QCR-240 with Bendix connector (from SBE 11 Surface PAR Input), 30 m, DN 31475
- 801238 To Surface PAR QSR-240 or -2200 or QCR-240 or -2200 with Lemo connector (from SBE 11 Surface PAR Input), 30 m, DN 32434
- 801237 To SBE 14 (from SBE 11 Remote Out), 100 m, DN 32433
- 171890 To computer COM port (from SBE 11 Serial Data Uplink or 9600 Baud Uplink), null modem cable, 3 m (replaces 801428, DN 32798)
- 17015 To AC power supply (U.S. Standard)
- To SBE 32C (compact)
50145 SBE 9plus to SBE 32C Mount Kit (document 67069)
- To SBE 32 (full size)
50199 SBE 9plus to SBE 32 Extension Stand Mount Kit (document 67074)
- To Electronics rack
30017 Deck unit rack mount ear kit (document 67059)
Sensors to SBE 9plus
- 50109 SBE 5T or 43 to 9plus Mount Kit
- SBE 3 and 4 pair to SBE 9plus (vertical only)
50083 Aluminum Mount Kit (contains 50084 and 50085)
50084 Aluminum TC Sensor Mount Block Assembly
50085 Aluminum TC Sensor Mount Bar Assembly
- SBE 3 and 4 pair to SBE 9plus Aluminum (vertical or horizontal)
50083.1 Aluminum Mount Kit (contains 50084.1 and 50085.1)
50084.1 Aluminum TC Sensor Mount Block Assembly
50085.1 Aluminum TC Sensor Mount Bar Assembly
- SBE 3 and 4 pair to SBE 9plus Titanium (vertical or horizontal)
50131 Titanium TC Sensor Mount Kit (contains 50132 and 50084.2)
50132 Titanium TC Sensor Mount Bar Assembly
50084.2 Titanium TC Sensor Mount Block Assembly
- Bottom Contact Switch to SBE 9plus (vertical)
50100 Bottom Contact Switch to SBE 9plus Housing Mount Kit
50314 Bottom Contact Switch to CTD Cage Mount Kit
- 90199 CTD plumbing kit (document 67022)
- 90088 CTD plumbing & TC duct tubing kit (document 67018)
Note: This kit includes flexible tubing for plumbing TC duct, but does not include TC duct. For TC duct parts, see 90085 below.
- 90085 TC duct & plumbing kit (document 67051)
- 50070 O-ring kit (document 67009)
- 50246 Conductivity disconnect fitting spare O-ring kit
- 50089 Jackscrew kit
- 50025 Pressure sensor oil refill kit (document 67066)
- 50024 Hardware kit for SBE 9plus with aluminum housing (document 67053)
- 50138 Hardware kit for SBE 9plus with titanium housing (document 67131)
- varies Conductivity cell tube support kit (document 67068)
- 50088 Seaspares kit for SBE 9plus with aluminum housing & XSG/AG connectors (hardware, O-rings, cables, dummy plugs, connectors, zinc anodes, fuses, etc.) (document 67025)
- 50139 Seaspares kit for SBE 9plus with titanium housing & XSG/AG connectors (hardware, O-rings, cables, dummy plugs, connectors, fuses, etc.) (document 67128)
- 50321 Seaspares kit for SBE 9plus with aluminum housing & wet-pluggable connectors (hardware, O-rings, cables, dummy plugs, connectors, zinc anodes, fuses, etc.) (document 67129)
- 50322 Seaspares kit for SBE 9plus with titanium housing & wet-pluggable connectors (hardware, O-rings, cables, dummy plugs, connectors, fuses, etc.) (document 67130)
- 31634 Hardigg shipping case (AL4915-1105) (photo of 9plus in this shipping case)
Compare Profiling CTDs (Conductivity, Temperature, and Pressure)
|SBE||Sampling Rate||Channels for Auxiliary Sensors||Memory||Power||Real-Time Data||Comments|
|SBE 911plus CTD (9plus CTD & 11plus Deck Unit)||24 Hz||
|16 Mb with optional SBE 17plus V2||
(with optional SBE 17plus V2)
|World's most accurate, high resolution CTD, premium sensors, multi-parameter support, water sampler control.|
|SBE 25plus Sealogger CTD||16 Hz||8 A/D;
May require SBE 36 CTD Deck Unit & PDIM
|High-resolution logging CTD with multi-parameter support. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 25 Sealogger CTD
||8 Hz||7 A/D||8 Mb||
May require SBE 36 CTD Deck Unit & PDIM
|Replaced by SBE 25plus in 2012. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 19plus V2 SeaCAT Profiler CTD||4 Hz||6 A/D;
May require SBE 36 CTD Deck Unit & PDIM
|Personal CTD, small, self-contained, adequate resolution. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 19plus SeaCAT Profiler CTD
||4 Hz||4 A/D; optional PAR||8 Mb||
May require SBE 36 CTD Deck Unit & PDIM
|Replaced by SBE 19plus V2 in 2008. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 19 SeaCAT Profiler CTD
||2 Hz||4 A/D||1 - 8 Mb||
May require SBE 36 CTD Deck Unit & PDIM
|Replaced by SBE 19plus in 2001. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 49 FastCAT CTD Sensor||16 Hz||
May require SBE 36 CTD Deck Unit & PDIM
|For towed vehicle, ROV, AUV, or other autonomous profiling applications. Water sampler control with SBE 33 Carousel Deck Unit.|
|SBE 52-MP Moored Profiler CTD & (optional) Dissolved Oxygen Sensor||1 Hz||1 frequency channel for dissolved oxygen sensor||28,000 samples||Intended for moored profiling applications on device that is winched up and down from a buoy or bottom-mounted platform.|
|SBE 41/41CP CTD Module for Autonomous Profiling Floats (Argo)||OEM CTD for sub-surface oceanographic float that surfaces at regular intervals, transmits new drift position and in situ measurements to ARGOS satellite system. CTD obtains latest temperature and salinity profile for transmission on each ascent. Also available is a Navis Autonomous Profiling Float, Navis BGC Autonomous Profiling Float with Biogeochemical Sensors, and Navis BGCi Autonomous Profiling Float with Integrated Biogeochemical Sensors|
|Glider Payload CTD (GPCTD) and Slocum Glider Payload CTD||OEM CTD for autonomous gliders. Generic Glider Payload CTD (GPCTD) is modular, low-power profiling instrument that measures C, T, P, and (optional) Dissolved Oxygen. Slocum Glider Payload CTD provides retrofit/replacement for CTDs on Slocum gliders. Designs share many features, but there are differences in packaging, sampling abilities, power consumption, and installation (see individual data sheets).|
1. See Application Note 82: Guide to Specifying a CTD.
2. products are no longer in production. Follow the links above to the product page to retrieve manuals and application notes for these older products.