Frequently Asked Questions

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.

*Notes:
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. Read below for information on repairing / recalibrating auxiliary sensors manufactured by other companies:

Sea-Bird does not repair or recalibrate other manufacturers’ instruments that have been integrated with Sea-Bird equipment. If an auxiliary sensor needs to be repaired or recalibrated, we recommend that you send it directly to the manufacturer. If you send it to Sea-Bird, we will have to send it to the manufacturer, resulting in additional shipping (and possibly customs) expenses for you.

Note: Apparent malfunctioning of an auxiliary sensor can be caused by many things, including incorrect configuration (.con or .xmlcon) file, incorrect instrument setup, incorrect or leaky cables, poor mounting scheme, etc.

• If you are not certain that the auxiliary sensor needs to be repaired, Sea-Bird can help you troubleshoot the system by phone or e-mail at no charge.

• Alternatively, if you ship us the entire system, we can troubleshoot at the factory for our standard charges (see the FAQ above this for troubleshooting description). If we determine that the auxiliary sensor does need to be repaired, we will coordinate with you on shipment of the sensor to the manufacturer.

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

Sea-Bird currently manufactures only 1 moored CTD that can accept auxiliary sensors, the SBE 16plus V2 SeaCAT (and its inductive modem version, the 16plus-IM V2). These instruments measure conductivity and temperature; a pressure sensor is optional. They have 6 differential A/D channels and 1 RS-232 channel available for auxiliary sensors, which can be plugged into the CTD end cap.

The SBE 37 MicroCAT family includes CTDs that are integrated with a dissolved oxygen sensor at the factory.

Notes:

• The SBE 19plus V2 SeaCAT, intended primarily for profiling applications, can also be used in moored mode. The 19plus V2 also has 6 differential A/D channels and 1 RS-232 channel available for auxiliary sensors. When in moored mode, it functions similar to a 16plus V2 with optional pressure sensor.
• The older versions of these products, the SBE 16 / 16plus / 16plus-IM and SBE 19 / 19plus, also accept auxiliary sensors.

See Product Selection Guide for a table summarizing the features of all our moored instruments.

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 or floats from other manufacturers. The SBE 41N CTD is integrated with Sea-Bird’s Navis Float with Integrated Biogeochemical Sensors and Navis BGCi + pH Float with Integrated Biogeochemical Sensors.

See Product Selection Guide for a table summarizing the features of our profiling CTDs.

Sea-Bird does not publish prices on the website. Please contact us for pricing:

• Email seabird@seabird.com,
• Phone +1 425-643-9866, or
• Fill out our Quote Request Form

IAPSO standard seawater is available in 250 ml vials. For more information and purchase inquiry, e-mail osil@oceanscientific.co.uk.

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.

On the product page for each instrument, there are two tabs that provide ordering information:

• Click the Configuration tab to see all the features and options available on our price list. The Configuration tab provides explanatory information, illustrations, and photographs describing each item.
• Click the Accessories tab to see cables, mount kits, and/or spare parts for the products.

Third Party Sensor Configuration lists instruments and integration options for sensors produced by other manufacturers (altimeters, fluorometers, transmissometers, etc.).