AN45: Guide to SBE 32 Carousel Water Sampler Configuration Selections

Introduction

The SBE 32 Carousel Water Sampler is defined by the intended application(s) and control methods, as well as the Carousel model, number and size of bottles, maximum depth rating, and connector type. Many of these configuration selections interact; for example, the number of bottle positions and maximum bottle size is dependent on the Carousel model. Consider the physical requirements of the intended application(s), the interface issues, and make the following choices:

• CTD/Instrument to be used with the Carousel —
  - SBE 9plus CTD
  - SBE 19, 19plus, 19plus V2, 25, or 25plus CTD
  - SBE 49 CTD
  - SBE 50 Pressure Sensor
  - No CTD
• Bottle closure control method —
  - Real-time (bottles are closed by command from the ship, typically while monitoring real-time CTD data)
  - Autonomous (bottles are closed at pre-programmed pressures or times; no conducting wire is required)
• Number of bottle positions * —
  - 12
  - 24
  - 36
• Maximum bottle size (volume) * —
  - Accommodates bottles from 1.2 to 30 liters, depending on Carousel model and number of bottle positions
• Maximum depth rating * —
  - 6800 meters (22,300 ft)
  - 7000 meters (22,900 ft)
  - 10,500 meters (34,400 ft)
• Bulkhead and cable connectors —
  - Glass-reinforced epoxy (XSG/AG)
  - Wet-pluggable (MCBH)
• Carousel model —
  - Full-Size (SBE 32)
  - Compact (SBE 32C)
  - Sub-Compact (SBE 32SC)
• Amount of flexibility —
  - Design a system for one application
  - Design a system that can easily be reconfigured in the field to work with a variety of CTDs and bottle closure control methods

Each of these selections is described in detail below.

* Note: Sea-Bird also manufactures a small, lightweight, economical water sampler, the SBE 55 ECO Water Sampler. The ECO, available in a 3- or 6-bottle configuration with 4-liter bottles, is rated for 600 meters. The ECO can be used with the SBE 19, 19plus, 19plus V2, 25, 25plus, or 49, and provides autonomous or real-time operation.

 

CTD and Bottle Closure Control Method

Bottle Closure Control Method	Control	CTD/Instrument
Real-Time (bottles closed by command from the ship)	SBE 11plus Deck Unit	SBE 9plus CTD
	SBE 33 Deck Unit	BE 19 / 19plus / 19plus V2 / 25 / 25plus CTD
		SBE 49 CTD
		None
Autonomous (no conducting wire required; bottles closed automatically based on pre-programmed pressures or times)	SBE 17plus V2 Searam Recorder and Auto Fire Module	SBE 9plus
	Carousel Auto Fire Module (AFM)	BE 19 / 19plus / 19plus V2 / 25 / 25plus CTD
		SBE 50 Pressure Sensor
		None

 

Each of these combinations is described below:

Real-Time Data Acquisition and Control (bottles closed by command from the ship)

SBE 11plus Deck Unit The Carousel is designed to be connected directly to the SBE 9plus CTD and powered and controlled via the SBE 911plus modem channel. Bottles may be closed using the push-buttons on the SBE 11plus, or via the RS-232C modem connector on the back of the SBE 11plus while acquiring real-time data with Seasave (Sea-Bird real-time data acquisition software). The SBE 11plus includes a NMEA Interface to support NMEA 0183 protocol, and an interface for a Surface PAR sensor. Note: The modem (Carousel command) channel is included on the current production version of both the SBE 9plus and the SBE 11plus V2. It was optional on all 9plus CTDs with serial number 785 and lower, and on all 11plus Deck Units (V1 and V2) with serial number 700 and lower.

SBE 33 Carousel Deck Unit With the addition of a Serial Interface, the Carousel can also be powered and controlled using the SBE 33, and can be used with or without a CTD (SBE 19, 19plus, 19plus V2, 25, 25plus, or 49 CTD). The Serial Interface provides real-time data telemetry capability and surface power for these CTDs, and permits the control of the Carousel through the SBE 33 front panel controls or via Seasave. When used without a CTD, bottles are closed with the SBE 33 front panel controls; depth determination must be approximated by monitoring the cable payout. The SBE 33 has a NMEA Interface to support NMEA 0183 protocol, and an interface for a Surface PAR sensor.

 

Autonomous Data Acquisition and Control (no conducting wire required; bottles closed automatically based on pre-programmed pressures or times)

Autonomous sampling does not provide water sample quality equal to real-time sampling; it is a compromise intended to serve users who do not have real-time capability on their vessel. See Note on Water Sample Quality from Autonomous Samples below.

SBE 17plus V2 Searam Recorder and Auto Fire Module The SBE 17plus V2, mounted with the SBE 9plus CTD, allows the Carousel to operate autonomously on non-conducting cables. Using CTD pressure data from the 9plus and a programmable table of bottle closure pressures, the 17plus signals the Carousel to close bottles on upcast. Built-in logic and user-input parameters provide control in determining when the upcast begins, preventing accidental bottle closure caused by temporary upward movements during downcast. Power is supplied to the 9plus and Carousel by the 17plus' batteries, and data from the 9plus is stored in the 17plus memory.

Carousel Auto Fire Module (AFM) The AFM, mounted on or near the Carousel, allows the Carousel to operate autonomously on non-conducting cables, with or without a CTD. Used without a CTD, the AFM is programmed to fire bottles at pre-defined intervals of elapsed time. The point at which samples are taken is determined (approximately) by monitoring cable payout and elapsed time. Used with an SBE 19, 19plus, 19plus V2, 25, or 25plus CTD or an SBE 50 Pressure Sensor, the AFM monitors real-time pressure data transmitted by the CTD / SBE 50, and fires bottles at pre-defined pressures (depths) on upcast or downcast, or whenever the CTD / SBE 50 is stationary for a specified period of time. Power is supplied to the Carousel by the AFM’s batteries; bottle number, firing confirmation, and five scans of CTD / SBE 50 data are recorded in the AFM memory for each bottle fired.

Note on Water Sample Quality from Autonomous Samples

The 17plus and AFM auto fire feature enables a ship without a slip ring and electro-mechanical cable to gather CTD data and collect water samples without the need for real-time CTD data. However, dynamic conditions affect the quality (validity) of water samples in several ways:

1. Oceanographic conditions (for example, internal waves and currents) cause density surfaces to move continuously, causing water of a given salinity to move up and down. Scientists generally prefer to view real-time CTD data on the downcast, to see the temperature/salinity/density structure. Then, on the upcast, they can stop the water sampler at depths where gradients are small, before closing each bottle; higher quality water samples are obtained, because dynamic errors are smaller.
2. If the CTD/water sampler package does not stop to fire a bottle, the water in the bottle is a mixture of water from many meters below the firing point (assuming you are taking water samples on upcast). If moving at 1 m/sec, a bottle’s flushing constant is typically five to eight volumes, with water flushing slowly at the bottle inside wall and faster toward the bottle center. For a 5-liter bottle, the trapped sample contains a mix of water from a cylinder in the water column with diameter equal to the bottle inner diameter and volume of 25 - 40 liters (i.e., height of the cylinder is five to eight times the bottle height). Scientists prefer to stop the package to allow bottles to flush freely for several minutes before closing to obtain highest quality water samples.

The AFM (but not the 17plus) can be programmed to sample when stationary, eliminating the flushing problem (2). However, the lack of real-time data can still result in samples being taken in areas with large gradients (1), because the user can only estimate the depth of the gradients, and can only estimate the actual package depth from the cable payout.

While autonomous sampling can be a convenient alternative to real-time water sampler control, the quality of the samples is generally lower than for samples collected with a real-time system.

 

Number of Bottle Positions

Carousels are available for 12, 24, or 36 bottles, defining the number of lanyard release latches on the pylon, number of bottle mounts, and the diameter of the bottle mounting stand. The 36-bottle Carousel is custom; consult Sea-Bird.

 

Maximum Bottle Size

The size (volume) of bottles to be used affects the size of the bottle stand. Typically, a Carousel built for bottles of one size accommodates bottles of all smaller sizes (Exceptions: SBE 32 Full-Size Carousel built for 5-liter bottles does not accommodate 2.5-liter bottles; SBE 32 Full-Size Carousel and 32SC Sub-Compact Carousel built for 1.7-liter bottles does not accommodate 1.2-liter bottles). Consider shipboard storage and handling space limitations, and try to anticipate the maximum bottle size that you will want. For example, if the immediate need is for twelve 5-liter bottles, but 10-liter bottles may be desired in the future, specify a twelve position, 10-liter Carousel.

 

Housing Depth Rating and Connectors

The Carousel pressure housing is available in the following materials and depth ratings:

• anodized Aluminum, 6,800 meters (22,300 ft)
• Titanium, 7000 or 10,500 meters (22,900 or 34,400 ft)

The Carousel is available with glass-reinforced epoxy (XSG/AG) or wet-pluggable (MCBH) connectors. Order the Carousel with connectors to match the type on the equipment (CTD, 17plus, AFM as applicable) you will be connecting to it — interface cables have the same connector type on both ends.

All housing depth and connector choices are available for all Carousel models (SBE 32, 32C, and 32SC).

 

Carousel Model

Full-Size Carousel (SBE 32) —   a 12-, 24-, or 36-position sampler (12-bottle Carousels for all bottle sizes through 30 liters; 24- and 36-bottle Carousels for bottles of 12-liter capacity and less). The SBE 32 includes a CTD extension stand for mounting an SBE 9plus, 19, 19plus, 19plus V2, 25, 25plus, or 49 CTD with auxiliary sensors and equipment (auto fire instrument, transmissometer, fluorometer, etc.) in a horizontal position below the bottle stand.   Note: Bottle mount stand height and diameter and CTD extension stand height varies, depending on number and size of bottles. See the SBE 32 specifications or manual for details.

SBE 32 Full-Size Carousel (shown with SBE 9plus CTD)

Compact Carousel (SBE 32C) — a 12-position sampler for 8-liter bottles. The bottle mount stand diameter is 2.5 cm (1 inch) smaller than for the comparable Full-Size Carousel, and the height is designed to fit through a 1 m x 1 m door. The 32C does not have an extension stand for mounting a CTD. To provide room for mounting a CTD and accessories (AFM, fluorometer, transmissometer, etc.), the bottle positions are closely spaced into two arcs, the centers of which are 180 degrees apart. This leaves four auxiliary mounting positions between the ends of the arcs for mounting a CTD and accessories. Because of the tight bottle spacing and smaller stand diameter, reversing thermometers would extend outside the bottle stand, and their use on an SBE 32C is not recommended. — An SBE 19/19plus/19plus V2, or 49 CTD mounts vertically in one of the auxiliary mounting positions, using an accessory mounting fixture. — Similarly, the SBE 25/25plus CTD main housing mounts vertically in one of the auxiliary mounting positions. Its standard modular sensors (SBE 3 Temperature Sensor, SBE 4 Conductivity Sensor, SBE 5 Pump for SBE 25plus; those and SBE 29 Pressure Sensor for SBE 25) together mount vertically in a second auxiliary mounting position. — Auxiliary sensors and equipment (AFM, fluorometer, etc.) mount to any available auxiliary mounting positions. — A horizontal-mounting bracket for the SBE 9plus CTD underwater unit (with or without the SBE 17plus) allows it to be mounted underneath and inside the bottle stand.   Sub-Compact Carousel (SBE 32SC) —  a 12-position sampler for 1.7- or 2.5-liter bottles. The bottle mount stand diameter is 29 cm (11.5 inch) smaller than for the comparable Full-Size Carousel, and the height is designed to fit through a 1 m x 1 m door. The 32SC does not have an extension stand for mounting a CTD, and does not have sidebars. The SBE 32SC is designed for use with an SBE 19, 19plus, 19plus V2, 25, or 25plus CTD; it is not compatible with the SBE 9plus CTD. To provide room for mounting a CTD and accessories (AFM, fluorometer, transmissometer, etc.), the bottle positions are closely spaced into two arcs, the centers of which are 180 degrees apart. This leaves four auxiliary mounting positions between the ends of the arcs for mounting a CTD and accessories. Because of the tight bottle spacing and smaller stand diameter, reversing thermometers would extend outside the bottle stand, and their use on an SBE 32SC is not recommended. — An SBE 19/19plus/19plus V2, or 49 CTD mounts vertically in one of the auxiliary mounting positions, using an accessory mounting fixture. — Similarly, the SBE 25/25plus CTD main housing mounts vertically in one of the auxiliary mounting positions. Its standard modular sensors (SBE 3 Temperature Sensor, SBE 4 Conductivity Sensor, SBE 5 Pump, and SBE 29 Pressure Sensor) together mount vertically in a second auxiliary mounting position. — Auxiliary sensors and equipment (AFM, fluorometer, etc.) mount to any available auxiliary mounting positions.

SBE 32C Compact Carousel (shown with SBE 9plus CTD)   SBE 32C Compact Carousel (shown with SBE 19 CTD); SBE 32SC Sub-Compact Carousel similar (but without sidebars) [diameter = 70 cm (27.5 in.); height = 79 or 99 cm (31 or 39 in.)]

Note: As shown below, the latch spacing in the Full-Size Carousel pylon is different from the spacing in the Compact or Sub-Compact Carousel. This difference prevents substitution of the Full-Size Carousel pylon in the Compact or Sub-Compact Carousel, or vice versa, because the angle of the lanyards (which connect the latches to the bottles) will prevent proper functioning of the system.

Full-Size Carousel Pylon Detail

Compact or Sub-Compact Pylon Detail

 

Designing a Flexible System

Looking at the chart below, there are six application types:

1. Real-time with SBE 9plus CTD and SBE 11plus Deck Unit
2. Real-time with SBE 19, 19plus, 19plus V2, 25, 25plus, or 49 CTD and SBE 33 Deck Unit
3. Real-time with no CTD and SBE 33 Deck Unit
4. Autonomous with SBE 9plus CTD and SBE 17plus V2 Searam
5. Autonomous with SBE 19, 19plus, 19plus V2, 25, or 25plus CTD, or SBE 50 Pressure Sensor, and AFM
6. Autonomous with AFM and no CTD

All application types can be accommodated by ordering an SBE 32 (Full-Size) or an SBE 32C (Compact) that includes a Serial Interface (Modem Interface is always included). These provide a system with the most flexibility, allowing you to easily swap equipment at sea as needed for the application.

Application types 2, 3, 5, and 6 can be accommodated by ordering an SBE 32SC (Sub-Compact) that includes a Serial Interface.

Chart for Determining Appropriate Model and Carousel Pylon Interface Selection

Operation	CTD/ Instrument	Control	Carousel Model	Bottle Positions	Bottle Size (liters)	Carousel Pylon Interface Selection 1
Real-Time   (bottles closed by command from ship)	SBE 9plus 2	SBE 11plus Deck Unit	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	0 (Modem Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8	1 (Modem Interface + Serial Interface)
	SBE 19, 19plus, 19plus V2, 25, 25plus, or 49	SBE 33  Deck Unit	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	1 (Modem Interface + Serial Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8
			32SC 3	12	1.7 or 2.5
	None	SBE 33  Deck Unit	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	0 (Modem Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8
			32SC 3	12	1.7 or 2.5
Autonomous (no conducting wire required; bottles closed automatically based on pre-programmed pressures or times)	SBE 9plus 2	SBE 17plus V2 Searam	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	0 (Modem Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8
	SBE 19, 19plus,  19plus V2, 25, or 25plus CTD,  or SBE 50  Pressure Sensor	Carousel Auto Fire Module (AFM)	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	0 (Modem Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8
			32SC 3	12	1.7 or 2.5
	None	Carousel Auto Fire Module (AFM)	32	12	1.7, 2.5, 5, 8, 10, 12, 20, or 30	0 (Modem Interface)
				24	1.7, 2.5, 5, 8, 10, or 12
				36	(consult Sea-Bird)
			32C	12	8
			32SC 3	12	1.7 or 2.5

Notes:
¹ Interface Selections are for the Carousel electronics only. CTDs/Instruments (SBE 19, 19plus, 19plus V2, 25, 25plus, 49 CTD; SBE 50 Pressure Sensor) and controllers (SBE 11plus, SBE 33, SBE 17plus V2, AFM) are not included; order separately.
² The SBE 32SC’s (Sub-Compact) telemetry is compatible with the SBE 9plus, but the SBE 9plus is too large to allow a practical mounting in the SBE 32SC frame.
³ The SBE 55 ECO Water Sampler provides a small, lightweight, economical alternative to the SBE 32SC. The ECO, available in a 3- or 6-bottle configuration with 4-liter bottles, is rated for 600 meters. The ECO can be used with the SBE 19, 19plus, 19plus V2, 25, 25plus, or 49, and provides autonomous or real-time operation.

Links to other documents:

• Carousel Data Sheet
• Product Configuration Options & Accessories — SBE 32, 32C,and 32SC, Electronic Release Assemblies and Carousel Accessories, and Sample Bottles
• O.T.E. Sample Bottles description
• SBE Improved O.T.E. Sample Bottles description

 

Application Note Revision History

Date	Description
	- Initial release.
May 2003	- Reflect SBE 32 configuration option changes.
April 2004	- Note that SBE 32 Standard Carousel built for 5-liter bottles does not accommodate 2.5-liter bottles.
May 2004	- Clarify vertical mounting of SBE 19/19plus/25 CTD and accessories for SBE 32C and 32SC — not taking up a bottle space, using spaces at end of arcs.
July 2005	- Clarify that modem channel on SBE 11plus serial number < 700 and on SBE 9plus with serial number < 785 was optional, standard after that. - Clarify that SBE 32 can be used with SBE 11plus V1. - Remove '90208' from AFM name (90208 is AFM with XSG/AG connectors; SBE 32 can also be used with AFM with wet-pluggable connectors).
July 2006	- Add information that can use SBE 49 with SBE 32 (with serial interface) and SBE 33, but not compatible with NMEA or Surface PAR. - Note that SBE 32 Standard or Sub-Compact (SC) built for 1.7 liter bottles does not accommodate 1.2 liter bottles.
August 2006	- Add information about disadvantages of autonomous sampling vs real-time sampling.
May 2007	- Provide basic information on SBE 55 ECO Water Sampler, and refer to SBE 55 datasheet.
March 2008	- Add applicability to 19plus V2 SeaCAT CTD.
February 2010	- Seasave now allows acquisition of NMEA data for SBE 49 used with SBE 33. - NMEA interface on SBE 33 is now always included. - Update address.
February 2011	- In Carousel Model section: Note that Subcompact (SC) does not have sidebars.
July 2012	- Add applicability to 25plus Sealogger. - Surface PAR interface on SBE 33 is now always included.
September 2014	- Update for consistency with current price list language for currently available features/selections. - Remove information that Seasave does not allow Surface PAR acquisition with SBE 49; this capability was added in Seasave version 7.23.2. - Update link to SBE 55 datasheet for consistency with new website.