The Sea-Bird Journal

A publication of Sea-Bird Electronics, Inc. Issue #4 Oct. 1993

SEA-BIRD INTRODUCES NEW WATER SAMPLER

Sea-Bird introduced its new SBE 32 Carousel water sampler this month at Oceans '93 in Victoria, British Columbia. The Carousel's unique design is free of the reliability problems encountered with existing motor-driven water samplers. In contrast to earlier systems using stepper and gear motors that can bind up under pressure or at low temperatures, each of the Carousel's bottle positions has its own simple and reliable magnetic actuator, and there are no moving seals. Available in both 12 and 24 bottle configurations, the Carousel can support bottles of up to 30 liter size.

The SBE 32 Carousel can be powered and controlled by a modem-equipped Sea-Bird 911plus CTD, eliminating the need for a dedicated deck unit. The Carousel permits bottles to be closed in any order, and operates without interruption of CTD data or power.

For stand-alone operation, the SBE 33 Carousel Deck Unit provides single-wire power and control functions. Bottles can be fired by a front panel pushbutton, or by computer control. Optional interfaces in the Carousel Deck and Underwater Units provide power and real-time data telemetry capability for Sea-Bird's SBE 19 Seacat Profiler and SBE 25 Sealogger CTD while retaining all water sampler control functions. Similar interfaces are available to support CTD systems designed by Neil Brown. In each case, power is also available to operate auxiliary sensors and equipment not otherwise supported by these CTDs.

The SBE 32 Carousel is priced lower than comparable water samplers made by other manufacturers. Also, the electronics/release mechanism is sold separately and substitutes mechanically for most pylons found in other samplers. This allows bottles and mount stands from other manufacturers to be used to upgrade to Carousel's ease of operation and reliability at minimum expense.

911plus MAKES WORLD'S DEEPEST CAST

Dr. Keisuke Taira of the University of Tokyo, physical oceanographer and chief scientist aboard the RV Hakuho, used a titanium Sea-Bird 911plus CTD in December 1992 to profile to within 7 meters of the bottom of the Challenger Deep in the Marianas Trench. At 11°22.62'N, 142°34.96'E, scientists measured a depth of 10,561 meters using a Sea-Beam sonar. The 911plus profile data was used to correct the Sea-Beam data for variations in sound speed. The deepest pressure measurement was 11,188 decibars, and the corrected depth was calculated to be 10,918 meters. The RV Hakuho is equipped with a special winch, and unique titanium cable, making it the only vessel in the world with this capability. Previously, the deepest known CTD measurement was also made with a Sea-Bird 9/11 CTD aboard the Hakuho to a depth of 8000 meters. At that time, she was the only vessel known to have made CTD profiles deeper than about 6500 meters. The only CTD capable of meeting the Hakuho's requirements is the 911plus.

PRODUCT NEWS

NMEA 0183 GPS Interface Options

Sea-Bird's real-time instruments can now be configured to acquire a standard NMEA 0183 GPS data string, and append position data to the CTD data. The junction box included with the Thermosalinograph has a built-in NMEA 0183 interface, and this same junction box, PN 90158, can be used with Seacat Profilers and Sealogger CTDs. A similar interface, option 11-4 for SBE 11plus, is available for the 911plus CTD. The NMEA interface capability for all these instruments is supported by Seasoft 4.030 or higher.

Seacat Survival Story

Charlie Fitzpatrick, Department of Fisheries & Oceans, in St. Johns, Newfoundland, reported that one of his Seacat Profilers had been mounted to a trawl net, and was lost at sea in the Spring of 1991. The net was grappled during the summer of 1992 and the Seacat, still retaining its good data, was recovered.

SOFTWARE & DATA ANALYSIS

Seasoft© Version 4 is a major part of our product line, and as such, is under constant refinement and enhancement. In just 10 months since December 1992, starting with version 4.019, several useful new modules and features were incorporated into Seasoft and improvements too numerous to itemize herein have been added. A complete listing of the change history is kept on file and a change summary is included in the back of each Seasoft Manual.

In version 4.019, 4 new features were included. The ASCIIIN utility added a header to an ASCII file containing rows and columns of data generated by a non Seasoft program (e.g. spreadsheet). A new CONTOUR module was added to generate density contours that can be overlaid on TS plots. The SEACALC utility, a "seawater calculator", was added and allows over a dozen derived variables to be computed. Changing the input values of one or more of several primary variables (temp, cond, press, etc.) causes the derived variables to be recalculated. SEAPLOT was enhanced to produce multi-file overlays (density over TS, or any plot over any other) interactively or in batch mode, and batch mode waterfall plots.

Soon thereafter, in Version 4.020, BUOYANCY and WFILTER were also added to Seasoft. Buoyancy frequency and stability are calculated using the Fofonoff adiabatic leveling method. WFILTER provides 4 types of window filters and a median filter for data smoothing of .CNV files. Version 4.025 added control support for the General Oceanic's 1016 Intelligent Rosette. Version 4.027 added support for the NMEA 0183 GPS data interface in the SBE 11plus, and version 4.030 expanded NMEA 0183 interface support to include the Seacat and Sealogger CTD. Version 4.032 was released 18 Oct. 1993, adding support for controlling Sea-Bird's new Carousel water sampler. The next version of Seasoft will incorporate the ITS 90 temperature standard, and there will be a skip in the numbering sequence to 4.200. Version 4.103 is the latest release of Seasoft for Waves.

SBE TECHNICAL CORNER

USER ALERT - SBE 16DO - Users of SBE 16DO Seacat recorders, shipped before September 1993, are advised that a hardware fault in the "latched DO" circuit can cause erroneous oxygen values.

SBE 16 DOs, special versions of the SBE 16 Seacat designed for moored dissolved oxygen measurements, have a "latched DO circuit which applies power to the oxygen sensor to polarize it, two minutes before the start of the programmed sample interval. Sea-Bird has recently discovered that this circuit can fail, preventing the polarizing voltage from "latching" on. However, evidence of this fault may not be obvious in the data because when the Seacat wakes up, the oxygen sensor becomes partially polarized during the 15 second interval used to run the pump before the data are recorded. Oxygen values from faulty instruments will be over-reported by 15 to 20% and will be noisy.

Sea-Bird is routinely correcting this fault on all 16DOs that are returned for calibration. Users who have not had their 16DOs serviced since September 93, should contact our Customer Service Manager to schedule this free repair.

Sea-Bird Home     Phone: (+1) 425-643-9866     E-mail: seabird@seabird.com