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SBE 56

SBE 56 Temperature Logger

Low-cost, high-accuracy, battery-powered temperature and time logger, with user-programmable sampling interval.

The SBE 56 is a low-cost, high-accuracy, fast-sampling temperature recorder with USB interface, internal battery, and memory. Data are uploaded upon recovery via the internal USB connector, and output in engineering units (degrees C, date and time). The high stability preserves the initial calibration accuracy and means less frequent (or no) calibrations. The SBE 56 delivers this accuracy and stability at a price you would expect for recorders that are less accurate, and is ideal for countless underwater recording applications.

Memory capacity exceeds 15 million samples. Battery endurance varies, depending on the sampling scheme. Sampling every 0.5 sec, the SBE 56 can be deployed for 1 month (5.3 million samples). Sampling 4 times per minute, the battery lasts almost 2 years.


  • Temperature and time, at user-programmable 0.5-sec to 9-hour intervals.
  • Internal memory and battery.
  • 1500 m plastic housing.
  • Internal USB 2.0 interface; open housing and plug in cable for setup or data upload.
  • Fast upload; approximately 40 minutes for full memory (> 15 million samples).
  • Easy-to-use Java-based software (compatible with nearly any computer operating system) for setup, upload, and data plotting.
  • Rigorous 11-point temperature calibration of each sensor.
  • Five-year limited warranty.


  • Aged and pressure-protected thermistor has a long history of exceptional accuracy and stability. The 0.5-sec time constant provides excellent accuracy (initial accuracy 0.002 °C) and resolution when fast sampling at 2 Hz (0.5 sec). It has exceptional stability; drift is typically less than 0.002 °C per year.
  • High-accuracy real-time clock.


Cutting edge design and manufacturing make extreme accuracy and precision possible, but our world-leading calibration capability  proves it. Every SBE 56 receives a rigorous 11-point temperature calibration in our state-of-the-art computer-controlled calibration bath systems, which are backed by in-house NIST-level metrology standards (water triple point and gallium melting point cells). Every SBE 56 is a true research-quality tool that elevates the quality of your work without straining your budget.


Measurement Range -5 to +45°C
Accuracy ± 0.002 °C (-5 to +35 °C); ± 0.01 °C (+35 to +45 C)
Typical Stability 0.0002 °C/month (0.002 °C/year)
Resolution 0.0001°C


Clock Accuracy 5 seconds/month
Power Supply & Consumption 3.6 V AA Saft LS14500 Lithium Battery (non-hazardous)
   5.3 million samples at 0.5-sec intervals (31 days)
   5.3 million samples at 1-sec intervals (61 days)
   4.9 million samples at 5-sec intervals (284 days)
   4.1 million samples at 15-sec intervals (717 days)
Memory Capacity 15.9 million samples
Housing, Depth Rating, & Weight Plastic, 1500 m, In air 0.2 kg, in water 0.05 kg


The list below includes (as applicable) the current product brochure, manual, and quick guide; software manual(s); and application notes.

For older SBE 56 product manuals, organized by instrument firmware version, click here.

If the USB driver does not install automatically when you connect to the SBE 56 via SeatermV2, click here to download the driver (

Title Type Publication Date PDF File
SBE 56 Brochure Product Brochure Monday, December 29, 2014 56brochureDec14.pdf
SBE 56 Manual Product Manual Wednesday, June 22, 2016 56_009.pdf
SBE 56 Quick Guide Product Quick Guide Thursday, February 27, 2014 56_referencesheet_006.pdf
Field Service Bulletin 28: SBE 39plus / SBE 56 USB Connectivity Problem Field Service Bulletins Wednesday, July 29, 2015 FSB28.pdf
Field Service Bulletin 25: SBE 56 Temperature Logger Field Service Bulletins Monday, April 4, 2011 FSB25.pdf
AN42: ITS-90 Temperature Scale Application Notes Wednesday, May 18, 2016 appnote42May16.pdf
AN57: Connector Care and Cable Installation Application Notes Tuesday, May 13, 2014 appnote57Jan14.pdf
AN71: Desiccant Use and Regeneration (drying) Application Notes Wednesday, May 18, 2016 Appnote71May16.pdf
AN83: Deployment of Moored Instruments Application Notes Thursday, May 19, 2016 appnote83May16.pdf
Deployment Endurance Calculator is an aid for quickly determining the maximum deployment length for a moored instrument, based on battery capacity. Deployment Endurance Calculator is part of our Seasoft V2 software suite.
Version 1.7.0 released March 23, 2016
DeploymentEnduranceCalcV1.7.0-b88.exe for Windows XP/Vista/7

SeatermV2© is a terminal program launcher for setup and data upload of Sea-Bird instruments developed or redesigned in 2006 and later. The common feature of this generation of instruments is the ability to output status responses in XML. SeatermV2 is part of our Seasoft V2 software suite.
Version 2.6.1 released June 1, 2016
SeatermV2.6.1-b12.exe for Windows XP/Vista/7

Why am I having trouble connecting via the SBE 39plus or SBE 56 internal USB connector?

In July 2015, Sea-Bird released updated software to address intermittent connectivity issues where the host computer or SeatermV2 cannot recognize an instrument communicating via its internal USB connector. Field Service Bulletin 28 describes the problem and the installation of updated software to solve the problem.

How often do I need to have my instrument and/or auxiliary sensors recalibrated? Can I recalibrate them myself?

General recommendations:

  • 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 —
    — SBE 18 pH sensor or SBE 27 pH/ORP sensor — recalibrate at the start of every cruise, and then at least once/month, depending on use and storage
    — Satlantic SeaFET pH sensor — recalibrate at least once/year. See FAQ tab on Satlantic's SeaFET page for details (How often does the SeaFET need to be calibrated?).
  • Transmissometer — usually do not require recalibration for several years. Recalibration at the manufacturer’s factory is the most practical method.

Profiling CTDs:

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.

Do I need to remove batteries before shipping my instrument for a deployment or to Sea-Bird?

Alkaline batteries can be shipped installed in the instrument. See Shipping Batteries for information on shipping instruments with Lithium or Nickel-Metal Hydride (NiMH) batteries.

What are the major steps involved in deploying a moored instrument?

Application Note 83: Deployment of Moored Instruments contains a checklist, which is intended as a guideline to assist you in developing a checklist specific to your operation and instrument setup.

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.

Conductivity Cell

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.

Temperature Sensor

In general, neither the accuracy of the temperature measurement nor the survival of the temperature sensor will be affected by ice.

Oxygen Sensor

For the SBE 43 and SBE 63 Dissolved Oxygen sensor, avoid prolonged exposure to freezing temperature, including during shipment. Do not store 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.

56 TEMPERATURE LOGGER - high accuracy (0.002 degrees C), up to 2 Hz sampling rate, 64 MB memory (15.9 million samples), 1500 meter plastic housing, single AA lithium battery, USB 2.0 interface, interface cable (172557), opening tool (234372), spares kit (60059), software, & complete documentation. SBE 56 in shipping box, with opening tool, desiccant, cable, and spare O-rings.

SBE 56 Spares & Accessories
50404 Lithium batteries (spare), package of two 3.6V AA cells (Saft LS 14500) One battery is included with standard shipment; these are spare. Shipping restrictions apply for shipping spare lithium batteries; see SBE 56 manual for details. Click here to buy Saft LS 14500 from Amazon.
172557 SBE 56 USB Type A to Mini-B cable, 1.8 m For uploading data using internal USB connector. Included with standard shipment; this is spare.
234372 SBE 56 Opening Tool Tool provides a good grip on SBE 56 end cap, making it easier to open to access USB connector.
60059 SBE 56 spare O-rings & desiccants Includes O-rings and desiccant.



  • 172557 To computer USB port, 1.8 m

Spare Parts

  • 50404 Lithium batteries, package of two 3.6V AA cells (Saft LS 14500) - Click here to buy Saft LS 14500 from Amazon.
  • 60059 Spares kit for SBE 56 (includes O-rings & desiccant capsules)
  • 234372 Tool for easy opening of SBE 56

Compare  Moored / Time Series Recording Instruments

SBE Measures
(C, T, P)
Auxiliary Sensors Memory Power Communication Real-Time
Internal External
SBE 16plus V2 SeaCAT C-T (P) Recorder C, T, P* 6 A/D; 1 RS-232 64 Mb RS-232 Optional pump
SBE 16plus SeaCAT C-T (P) Recorder
C, T, P* 4 A/D; optional RS-232 or PAR 8 Mb RS-232 or -485 Replaced by SBE 16plus V2 in 2008
SBE 16 SeaCAT C-T (P) Recorder
C, T, P* 4 A/D 1 Mb RS-232 Replaced by SBE 16plus in 2001
SBE 16plus-IM V2 SeaCAT C-T (P) Recorder C, T, P* 6 A/D; 1 RS-232 64 Mb   Inductive Modem Optional pump
SBE 16plus-IM SeaCAT C-T (P) Recorder
C, T, P* 4 A/D; optional RS-232 or PAR 8 Mb   Inductive Modem Replaced by SBE 16plus-IM V2 in 2008
SBE 19plus V2 SeaCAT Profiler CTD C, T, P 6 A/D; 
1 RS-232
64 Mb RS-232 Programmable mode — profiling or moored
SBE 19plus SeaCAT Profiler CTD
C, T, P 4 A/D; optional PAR 8 Mb RS-232 Replaced by SBE 19plus V2 in 2008
SBE 19 SeaCAT Profiler CTD
C, T, P 4 A/D 1 - 8 Mb RS-232 Replaced by SBE 19plus in 2001
SBE 37-SM MicroCAT C-T (P) Recorder C, T, P*   8 Mb RS-232 or -485  
SBE 37-SMP MicroCAT C-T (P) Recorder C, T, P*   8 Mb RS-232, RS-485, or SDI-12 Integral pump
SBE 37-SMP-IDO MicroCAT C-T-DO (P) Recorder C, T, P* Integrated DO 8 Mb RS-232 or -485 Integral pump; Replaced by SBE 37-SMP-ODO in 2014
SBE 37-SMP-ODO MicroCAT C-T-DO (P) Recorder C, T, P* Integrated Optical DO 8 Mb RS-232, RS-485, or SDI-12 Integral pump
HydroCAT C-T-(DO)-(P) Recorder C, T, P* Integrated Optical DO* 8 Mb RS-232 & SDI-12 Integral pump; for Coastal applications to 350 m
C-T-pH-(DO)-(P)-(Chl)-(NTU) Recorder
C, T, P* Integrated pH, Optical DO*, Chlorophyll*, Turbidity* 16 Mb RS-232 & SDI-12 Integral pump; for Coastal applications to 350 m
SeapHOx Ocean C-T-DO-pH (P) Recorder C, T, P* Integrated Optical DO, pH 8 Mb RS-232 37-SMP-ODO with SeaFET pH sensor; to 50 m
Deep SeapHOx Ocean C-T-DO-pH (P) Recorder C, T, P* Integrated Optical DO, pH 8 Mb RS-232 37-SMP-ODO with Deep SeaFET pH sensor; to 2000 m
SBE 37-IM MicroCAT C-T (P) Recorder C, T, P*   8 Mb   Inductive modem  
SBE 37-IMP MicroCAT C-T (P) Recorder C, T, P*   8 Mb   Inductive modem Integral pump
SBE 37-IMP-IDO MicroCAT C-T-DO (P) Recorder C, T, P* Integrated DO 8 Mb   Inductive modem Integral pump; Replaced by SBE 37-IMP-ODO in 2014
SBE 37-IMP-ODO MicroCAT C-T-DO (P) Recorder C, T, P* Integrated Optical DO 8 Mb   Inductive modem Integral pump
SBE 37-SI MicroCAT C-T (P) Recorder C, T, P*   8 Mb   RS-232 or -485  
SBE 37-SIP MicroCAT C-T (P) Recorder C, T, P*   8 Mb   RS-232 or -485 Integral pump

SBE 37-SIP-IDO MicroCAT C-T-DO (P) Sensor

C, T, P* Integrated DO 8 Mb   RS-232 or -485 Integral pump
SBE 39plus Temperature (P) Recorder T, P*   64 Mb Optional USB & RS-232 Optional  
SBE 39 Temperature (P) Recorder
T, P*   32 Mb Optional RS-232 Optional Replaced by SBE 39plus in 2014
SBE 39plus-IM Temperature (P) Recorder T, P*   64 Mb   Inductive Modem & USB  
SBE 39-IM Temperature (P) Recorder T, P*   32 Mb   Inductive modem Replaced by SBE 39plus-IM in 2016
SBE 56 Temperature Logger T   64 Mb   USB    
SBE 26plus Seagauge Wave & Tide Recorder T, P C optional 32 Mb RS-232
(tides, waves, & wave statistics)
Wave & tide recorder
SBE 26 Seagauge Wave & Tide Recorder
T, P C optional 8 Mb RS-232   Replaced by SBE 26plus in 2004
SBE 53 BPR Bottom Pressure Recorder T, P C optional 32 Mb RS-232 Bottom pressure recorder
SBE 54 Tsunameter Tsunami Pressure Sensor T, P   128 Mb Optional RS-232 Tsunami pressure sensor

C = conductivity, T = temperature, P = pressure, DO = dissolved oxygen
* = optional
products are no longer in production. Follow the links above to the product page to retrieve manuals and application notes for these older products.