- Low-cost, high-accuracy, battery-powered temperature and time logger.
- User-programmed sampling interval ranging from 0.5 seconds to 9 hours.
- Ideal for countless underwater temperature recording applications.
- Five-year limited warranty.
The SBE 56's pressure-protected thermistor has a 0.5 second time constant, providing 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. The SBE 56 delivers unprecedented accuracy and stability at a price you would expect to pay for similar recorders that are less accurate.
Before you assume that your application does not require such high accuracy and stability, remember that high stability preserves the initial calibration accuracy and means less frequent (or no) calibrations. For example, if you need only ±0.01 °C accuracy, you will not have to calibrate the SBE 56 for at least 5 years.
The SBE 56 is equipped with 64 MB memory, high-accuracy real time clock, plastic housing for depths up to 1500 meters (4900 ft), and USB 2.0 interface. Calibration coefficients are stored in memory; the included easy-to-use Java-based software (compatible with nearly any computer operating system) uploads the raw data, applies the coefficients, and outputs and plots finished data in degrees C and date and time.
BATTERY AND MEMORY ENDURANCE
Power consumption is very low. Using one 3.6 volt AA lithium battery, the SBE 56 acquires over 5.3 million samples at 0.5-second intervals (31 days). Sampling 4 times per minute, the battery lasts almost 2 years. The memory can store over 15 million samples (3 times the battery endurance).
SETUP AND DATA UPLOAD
The SBE 56 communicates with a computer via a standard USB 2.0 cable (included). To set up the SBE 56 or upload data, simply open the housing and plug the cable into the internal connector. Uploading large data sets is fast, approximately 40 minutes for a full memory (over 15 million samples).
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|
|Initial Accuracy||± 0.002 °C|
|Typical Stability||0.0002 °C/month (0.002 °C/year)|
|Clock Accuracy||5 seconds/month|
|Power Supply/Endurance||3.6 V AA Saft LS14500 Lithium Battery (non-hazardous)
5.3 million samples at 0.5-second intervals (31 days)
5.3 million samples at 1-second intervals (61 days)
4.9 million samples at 5-second intervals (284 days)
4.1 million samples at 15-second intervals (717 days)
|Data Memory||15.9 million samples|
|Housing||Plastic, 350 m (1148 ft)|
|Weight||In air 0.2 kg (0.4 lbs), in water 0.05 kg (0.1 lbs)|
|Title||Type||Publication Date||PDF File|
|SBE 56 Brochure||Product Brochure||Friday, May 25, 2012||56brochureMay12.pdf|
|SBE 56 Manual||Product Manual||Thursday, February 27, 2014||56_008.pdf|
|SBE 56 Quick Guide||Product Quick Guide||Thursday, February 27, 2014||56_referencesheet_006.pdf|
|AN42: ITS-90 Temperature Scale||Application Notes||Thursday, February 13, 2014||appnote42Feb14.pdf|
|AN57: Connector Care and Cable Installation||Application Notes||Tuesday, May 13, 2014||appnote57Jan14.pdf|
|AN71: Desiccant Use and Regeneration (drying)||Application Notes||Wednesday, January 15, 2014||Appnote71Jan14.pdf|
|AN83: Deployment of Moored Instruments||Application Notes||Friday, February 14, 2014||appnote83Feb14.pdf|
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.
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.
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.
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.
|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.|
|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
- 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
(C, T, P)
|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 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;
|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 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|
|C, T, P*||Integrated DO||8 Mb||RS-232 or -485||Integral pump|
|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|
|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|
|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|
|C, T, P*||Integrated DO||8 Mb||RS-232 or -485||Integral pump|
|Water Quality Monitor (WQM)||C, T, P||Integrated DO, chlorophyll fluorescence, turbidity (WQMx adds CDOM fluorescence, replaces turbidity with backscattering)||RS-232||Jointly developed by Sea-Bird Electronics and WET Labs; manufactured by WET Labs|
|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 39-IM Temperature (P) Recorder||T, P*||32 Mb||Inductive modem|
|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