SBE 54 Tsunami Pressure Sensor

SBE 54 Tsunameter Tsunami Pressure Sensor

Measures, records, and outputs pressure at user-programmable periods, at full ocean depth (photo shows short externally powered version as well as long version with internal batteries).

The SBE 54 continuously measures, records, and outputs pressure at user-programmable periods. Resolution is better than 1 mm at full ocean depth (6800 m) at the default 15-second sample period. The SBE 54’s sole purpose is to function as the heart of a deep-ocean tsunami detection system. Setup and operation require no user interaction. A power supply supervisor and watchdog timer ensure automatic recovery if power or normal operation is interrupted.

The SBE 54 combines a Paroscientific Digiquartz® pressure transducer, microcontroller, real-time clock with temperature-compensated crystal oscillator, precision temperature-compensated reference frequency, two high-resolution frequency acquisition circuits, EEPROM, and FLASH memory. Low power consumption makes multi-year, battery-powered deployments practical. The FLASH memory provides four years continuous backup of the raw pressure record, at a 15-second sample period. Preserving the entire time series in memory allows post-deployment review of the performance, as well as scientific analysis of the entire record. The EEPROM stores calibration coefficients and diagnostic information. The Digiquartz pressure sensor and frequency reference are tested and re-characterized at Sea-Bird to meet the demanding millimeter-scale sensitivity requirements.

FEATURES

  • Full ocean depth pressure (6800 m), with extremely high resolution (> 1 mm resolution at 15-sec sample period).
  • RS-232 interface.
  • Internal memory and simple, XML, real-time data.
  • Powered externally (short version) or internal batteries (long version).
  • Large memory and low power consumption for multi-year deployments.
  • Seasoft© for Waves Windows software package (setup, data upload, data conversion).
  • Five-year limited warranty.

COMPONENTS

  • Paroscientific Digiquartz® temperature-compensated pressure sensor, in four ranges from 1300 - 6800 m (2000 - 10,000 psia).
  • Microcontroller, real-time clock with temperature-compensated crystal oscillator, precision temperature-compensated reference frequency, two high-resolution frequency acquisition circuits.
    • Reference frequency that acquires pressure and pressure temperature outputs from pressure sensor accurate to 1 ppm and temperature calibrated to 50 ppb.
    • Pressure sensor, reference frequency, and acquisition circuits powered continuously to eliminate start-up transient errors.
    • Pressure and pressure temperature acquired simultaneously to eliminate phasing errors and increase measurement resolution.

OPTIONS

  • Short housing (externally powered), or
    Long housing with battery compartment for 12 D cells (LR-20 – Alkaline) or 6 DD Lithium cells (internal battery diode or’ed with external supply for backup to external power).
  • XSG/AG or wet-pluggable MCBH connector.
  • Lithium batteries (not supplied by Sea-Bird).

Performance

Measurement Range 0 to 1300, 2000, 4000, or 6800 m (2000, 3000, 6000, or 10,000 psia)
Resolution * 1.1 x 10 -7 of Digiquartz pressure range at default 15-sec sample period
(0.0011 psia [0.8 mm] with 10,000 psia sensor)
Reference Frequency Initial accuracy: 1 ppm
Temperature characterization: ± 0.1 x 10 -6 (-10 to 30° C), ± 0.05 x 10 -6 (0 to 10° C)
Aging: 3 x 10 -6 first year, 1 x 10 -6 after first year
Real-Time Clock Quartz TCXO watch-crystal, accuracy ± 2 ppm (5 sec/month)
Data Output Real-time pressure in ASCII engineering units (dbar, psia) at user-input sample period (1 - 240 sec; default 15 sec)
Memory 8.9 million samples (51 months at default 15-sec sample period)

* Sum of all uncertainties in measurement of pressure change < 1 mm over a duration of a few minutes and < 5 mm over a duration of minutes to hours, including ocean/instrument temperature changes of 0.25° C.

Electrical

External Power 12 – 28 VDC
Power Consumption 0.015 Watt at 15V, 0.016 Watt at 20V, 0.0018 Watt at 24V, 0.022 Watt at 28V (running continuously)
Battery Endurance 12 Alkaline D cells: 14 months (80% capacity);
6 Lithium DD cells: 37 months (80% capacity)

Mechanical

Housing & Depth Rating Titanium, 7000 m
Weight With long housing and alkaline batteries: in air 14.5 kg, in water 8.6 kg

 

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

For older SBE 54 product manuals, organized by instrument firmware version, click here.

Title Type Publication Date PDF File
SBE 54 Brochure Product Brochure Monday, August 24, 2015 54BrochureAug15.pdf
SBE 54 Manual Product Manual Wednesday, February 18, 2015 54_008.pdf
Field Service Bulletin 13: Jackscrew Replacements Field Service Bulletins Monday, March 8, 2010 FSB13.pdf
AN57: Connector Care and Cable Installation Application Notes Tuesday, May 13, 2014 appnote57Jan14.pdf
AN68: Using USB Ports to Communicate with Sea-Bird Instruments Application Notes Friday, October 19, 2012 appnote68Oct12.pdf
AN71: Desiccant Use and Regeneration (drying) Application Notes Wednesday, May 18, 2016 Appnote71May16.pdf
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


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

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 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:

  1. Thoroughly clean the connector with water, followed by alcohol.
  2. 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.

Replacing Connectors:

  • 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.

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.

What is the maximum cable length for real-time RS-232 data?

Cable length is one of the most misunderstood items in the RS-232 world. The RS-232 standard was originally developed decades ago for a 19200 baud rate, and defines the maximum cable length as 50 feet, or the cable length equal to a capacitance of 2500 pF. The capacitance rule is often forgotten; using a cable with low capacitance allows you to span longer distances without going beyond the limitations of the standard. Also, the maximum cable length mentioned in the standard is based on 19200 baud rate; if baud is reduced by a factor of 2 or 4, the maximum length increases dramatically. Using typical underwater cables, allowable combinations of cable length and baud rate for Sea-Bird instruments communicating with RS-232 are shown below:

Maximum Cable Length (meters) Maximum Baud Rate*
1600 600
800 1200
400 2400
200 4800
100 9600
50 19,200
25 38,400
16 57,600
8 115,200

*Note: Consult instrument manual for baud rates supported for your instrument.

 

Do you recommend a particular brand of alkaline D-cell batteries?

For Sea-Bird instruments that use alkaline D-cells, Sea-Bird uses Duracell MN 1300, LR20. While rare, we have seen a few problems with cheaper batteries over the years: they are more likely to leak, may vary in size (leading to loose batteries causing a bad power connection), and may not last as long.

Family . Housing Pressure Sensor/Range Connectors Temperature Sensor
54 . 3 – 7000 m (titanium), long housing (batteries) G – 2000 psia Digiquartz 1 – XSG/AG 0 – None
    4 – 7000 m (titanium), short housing (no batteries) H – 3000 psia Digiquartz 2 – MCBH  
      I – 6000 psia Digiquartz    
      J – 10,000 psia Digiquartz    

Example: 54.3J20 is an SBE 53 with 7000 m long housing, 10,000 psia Digiquartz pressure sensor, & MCBH connectors. See table below for description of each selection:

PART # DESCRIPTION NOTES
54

Tsunameter (Tsunami pressure sensor) - Includes Digiquartz pressure sensor, 128 MB Flash memory, titanium housing for 7000 m depth, RS-232 serial interface, 2.4 m data I/O cable (801385), software, & complete documentation.

SBE 54 continuously measures & outputs pressure every 15 seconds, with a pressure resolution of better than 1 mm at full ocean depth (7000 m). Its sole purpose is to function as heart of a deep ocean tsunami detection system. Standard SBE 54 is externally powered.

SBE 54 Housing Selections — MUST SELECT ONE
54.3xx0 Long housing with battery compartment for 12 D (LR-20) cells Short housing SBE 54 is externally powered. Long housing provides a battery compartment for 12 D alkaline cells (LR-20) or 6 DD Electrochem lithium cells (drop-in batteries with buttons); internal battery is diode or'ed with external supply for use as backup to external power supply.

Note: Sea-Bird does not supply Electrochem lithium batteries; you must purchase them elsewhere (see WGT's website for purchasing information). Shipping restrictions apply for Electrochem lithium batteries & assembled battery packs.
54.4xx0 Short housing, no battery compartment (externally powered)
SBE 54 Pressure Sensor Range (approximate maximum depth) Selections — MUST SELECT ONE
54.xGx0 2000 psia (1300 m) Digiquartz pressure sensor Pressure sensor is installed in connector end cap, & is not field-replaceable / swappable. While highest depth rating gives most flexibility in using SBE 54, 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 sensor's full scale range. For example, comparing 2000 psia (1300 m) & 10,000 psia (6800 m) sensors:
  • 2000 psia (1300 m) sensor ‑
    resolution = 1 x 10 -7 * 1300 m = 0.00013 m = 0.1 mm
  • 10,000 psia (6800 m) sensor ‑
    resolution = 1 x 10 -7 * 6800 m = 0.00068 m = 0.7 mm
54.xHx0 3000 psia (2000 m) Digiquartz pressure sensor
54.xIx0 6000 psia (4000 m) Digiquartz pressure sensor
54.xJx0 10,000 psia (6800 m) Digiquartz pressure sensor
SBE 54 Connector Selections — MUST SELECT ONE
54.xx10 XSG/AG connectors on instrument & data I/O cable 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.
  
54.xx20 Wet-pluggable (MCBH) connectors on instrument & data I/O cable
SBE 54 Spares & Accessories
801385 Data/Power cable (SBE 54 with no battery compartment), RMG-4FS to DB-9S & red/black twisted wire leads, 2.4 m (DN 32277)

These test cables are used for setting up system & uploading data from memory after recovery.

  • 801385 — Included with standard shipment for SBE 54 with XSG connector; this is spare.
  • 801206 — Included with standard shipment for SBE 54 with wet-pluggable connector; this is spare.
  • 801225 — Slightly less expensive alternative to 801385, for use with SBE 54 with internal batteries.
  • 801374 — Slightly less expensive alternative to 801206, for use with SBE 54 with internal batteries.
801206 Data/Power cable (SBE 54 with no battery compartment), Wet-pluggable, MCIL-4FS to DB-9S & red/black twisted wire leads, 2.4 m (DN 32366)
801225 Data I/O cable (SBE 54 with battery), RMG-4FS w/ DB-9S, 2.4 m (DN 32421)
801374 Data I/O cable (SBE 54 with battery), Wet-pluggable (MCIL-4FS) w/ DB-9S, 2.4 m (DN 32715)

 

Many cables, mount kits, and spare parts can be ordered online.

Cables

  • 801225 To computer COM port (from XSG connector), 2.4 m, DN 32421
  • 801374 To computer COM port (from Wet-pluggable connector), 2.4 m, DN 32715

Spare Parts

  • 50092 Jackscrew kit for SBE 16, 17plus, 19, 21, 25, 26/26plus, 52-MP, 53, 54, AFM, or PDIM
  • 60021 Battery end cap hardware & O-ring kit for SBE 16/16plus/16plus-IM/16plus V2/16plus-IM V2, 17plus, 19/19plus/19plus V2, 25, 26/26plus, 53, 54, 55, or AFM (document 67042)
  • 50056 Hardware kit for SBE 26/26plus, 53, or 54 (document 67016)

Compare  Moored / Time Series Recording Instruments

SBE Measures
(C, T, P)
Auxiliary Sensors Memory Power Communication Real-Time
Data
Comments
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
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.