(lopc) is the next generation in plankton profiling. the...
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11-50 Thornhill DriveDartmouth, Nova Scotia
Canada B3B 1S1
Tel: 902-468-2928Fax: 902-468-1388
www.brooke-ocean.com
The Laser Optical Plankton Counter (LOPC) is the next generation in plankton profiling. The LOPC’s high speed processing and improved detection plane provides detection counts at higher resolutions and higher concentrations with lower coincidence. This also allows the LOPC to be integrated into tow bodies such as the MVP, traveling at up to 12 knots and still providing reliable data. However, the LOPC is designed to be adaptable to any tow body and operate stand-alone as well.
High Resolution - Size detection range is 100 m - 35 mm
Shape profiles produced for plankton 1.5 - 35 mm6 3Improved coincidence limit (up to 10 counts/m )
Serial, analog and counter interface inputs
Flow speed estimation
Compact design allows easy integration to various towbodies
Single pressure case provides high reliability with low maintenance
Larger tunnel now available as interchangeable option
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Real-time graphical displayof collected data
Graphical display includes:ESD/bins histogram, shapeprofiles and charts such asCounts Per Second, CTDData, Flow Speed, etc.
Graphical User Interface
Features:Features:
LOPC
LOPC
Operation
Integration
The LOPC uses a high quality laser accompanied by precision optics to create a laser beam or plane which is used to detect a change in the laser path or ‘light blockage’, thus indicating a particle in transit through the tunnel. The detection band is very thin [1mm] and the scan rate is extremely fast (35 s) which combine to enable the LOPC to operate in very high concentrations of plankton while keeping coincidence levels very low.
With such a high resolution 0.1 mm - 35 mm (100 m - 35000 m) and the ability to individualize particles even at a high flow rate, extremely large amounts of data have to be processed. To accomplish this, the LOPC utilizes high speed signal processors and a combination of other analog and digital electronics.
The LOPC also provides interfaces for direct connection of external serial or analog instruments.
Data from these instruments is integrated into the main LOPC data stream, thus providing automatic cross referencing of data; all without requiring extra
conductors for the external instruments.
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LOPC 11/04
Quick Tip:The LOPC Deck Unit can be reconfigured to output a higher voltage if the situation requires. For example, to offset a high voltage drop on a very long sea cable.
Quick Tip:While the LOPC will operate with power and communications over a single pair of conductors, it is more efficient to use two pairs in parallel, especially useful on very long sea cables.
Quick Fact:The high resolution, precise detection beam and fast scan rate enables the LOPC to have a Coincidence
6Limit of ~10
Quick Fact:Users are supplied with a sample of precision manufactured ‘micro-beads’ which can be used to reproduce and verify the factory calibration of the LOPC.
TEST CABLE(5m)
SERIAL INTERFACE (RS232)
COMPUTER*
LOPCLOGGING
COMPUTER
LAB
DECK
115V / 60Hz- or -
240V / 50Hz
AC POWER CORD
AC IN
LOPC INTERFACE
SERIALINTERFACE
AC OUT
DECK UNIT
SEA CABLE*
INTERFACE CABLE**
* Required components; sold as an option with the LOPC system
LOPC on MacArtney’s Triaxus ...on Chelsea’s Nv-shuttle ...on Alex Herman’svertical OPC frame
...in Brooke Ocean Technology Ltd’sMoving Vessel Profiler Free Fall Fish
** Sold as an option with the LOPC system
AML CTD**LOPC
POWERSWITCH
Real-time data processing and display - collected data is processed in real-time and graphically displayed for immediate interpretation by the user.
Data Playback - raw data files can be replayed for post-deployment observation and analysis purposes.
Instrument control - the user interface provides the user with a simple interface to control the instrument (LOPC) without knowledge of the underlying instrument or control commands.
Data acquisition - The LOPC software acquires data from the instrument via a serial port and parses the data using a framed, binary byte-stuffing protocol.
EuphausiidsEuphausiids
LOPC
Data
Interface
Post
Software
Processing
Quick Fact:All charts and plots in the LOPC software contain auto scaling features as well as complete manual control if the user wishes.All settings and scaling is also saved and reloaded the next time the software is run.
The LOPC Interface Software offers real-timedata collection and graphical display.The LOPC Interface Software offers real-timedata collection and graphical display.
Detected plankton in the 100 - 1500 µm range are interpreted as counts and displayed in the binned histogram. (Actual histogram data generated with micro-beads.)
Digital controls allow users to monitor various data sources in real-time.
Alternate views can be selected such as the ‘Time Based Charts’ which graphically illustrate various data streams with respect to time and each other.
This particular screen is showing Depth vs. Time, Temperature vs. Time and Counts Per Second (CPS) vs. Time.
Larger plankton (1.5 mm - 35 mm) provide sufficient information to generate shape outlines or profiles.
These shape profiles scroll on the screen in near real-time to simulate the transit of the plankton through the tunnel.
This screen capture shows data collected during a calibration check using precision micro-beads.
Accessible control buttons allow the user to easily command the instrument.
This screen capture shows data collected during sea trials with an LOPC installed in a Moving Vessel Profiler (MVP) fish.
Software is also provided courtesy of Dr. Alex Herman (BIO) to enable users to perform post-processing of collected data and produce meaningful results quickly. The source code for this software is also provided so that users can customize it to meet their needs or use it as a starting point to develop their own software. The simple-to-use software can be downloaded from Dr. Herman’s website at www.alexherman.com by following the links to “LOPC Post-Processing”.
Menu commands control various options and settings.
Quick Fact:Scientific cruises are often too busy to closely monitor data as it is being collected. With the LOPC Software’s “data playback” feature, raw data files can be replayed and closely observed back in the lab as if they were being collected on the ship.
Specifications
Represented by:
Options
LOPC Options
- Deep Water Unit- Data Logger- Lab Unit- Larger Sampling Tunnel: 70mm x 175mm (2.5 X larger) [2.75” x 6.89”]
- CTD- Fluorometer
- Flowmeter- Pressure Sensor
- Other (consult factory)
External Sensor Options
The Laser Optical Plankton Counter was developed by Dr. Alex Herman of the Department of Fisheries and Oceans, Ocean Science Division, Bedford Institute of Oceanography.
Visit Dr. Herman’s personal website at www.alexherman.com
Physical/Mechanical
Electrical
Telemetry
Weight 8.6 Kg [19 lbs]
Construction Steel
Dimensions 19” Rackmount 3U x 9” deep
Voltage 120 VAC, 60 Hz*
1 It is desirable to operate the LOPC on a 2-pair (4-conductor) seacable if available. Is greatly increases power efficiency; especiallyuseful on longer cables.
* Other configurations available upon request
Deck Unit to PC RS-232, 115K baud
Standard DB-9 serial cable
Deck Unit to Sensor Powerline modem ( 100-450 Khz )
2-conductor cable
** The Deck Unit contains a multi-tap voltage system which allowsthe user to increase the voltage supplied to the LOPC if the situationrequires it. For example, operating the LOPC on a very long sea cableusing only a single pair of conductors.
Deck Unit
Physical/Mechanical
Electrical
Telemetry
Connectors (Endcap Bulkheads)
LOPC Measurement Capabilities
Weight in Air
Weight in Water
11.4 Kg [25 lbs]
6.0 Kg [13 lbs]
Construction Aluminum (anodized)
Depth Rating 660 m [2165 ft]
Voltage
Current
Power
140 VDC (supplied by Deck Unit)
100 - 300 mA*
< 20 W*
* Dependent on external components connected
1** A single pair of conductors provide both power and communications
Sensor to Deck Unit Powerline modem ( 100-450 Khz )
RS-485Ext. Serial Input
LOPC Interface
Serial InputAnalog Input
Size Detection Range
Sampling Aperture 70 mm x 70 mm [2-3/4” x 2-3/4”] (Nominal)
1.5 mm - 35 mm (shape profiles generated)
0.1 mm - 35 mm
Beam Cross-Section 1 mm x 35 mm [0.0394” x 1.375”] (Nominal)
Coincidence Limit ~10^6 particles/m^3
Min Tow (Flow) Rate 0.48 knots [0.25 m/s]
Max Tow (Flow) Rate 13.6 knots [7.0 m/s]
4-pin IE55 (male) [power and comm]
6-pin MCBH (female)8-pin MCBH (female)
2-conductor cable**
Underwater Sensor
7.95" [ 202mm ]
16.6
6"
[ 423m
m ]
9.45" [ 240mm ]
3.75" [ 95mm ]
Model Model
Serial No. Serial No.
11-50 Thornhill DriveDartmouth, Nova Scotia
Canada B3B 1S1Tel: 902-468-2928Fax: 902-468-1388
Lab LOPC
Deep Water LOPC
Deck Unit
Lab LOPC
The Lab LOPC is designed for sample analysis in a lab setting. The samples are passed through the sampling tube by means of a circulator (see reverse) or pumped water source. This unit is designed to accept various flow tube sizes based on available flow rate. The Lab LOPC is ideal for use in humid environments - all internal chambers are sealed and purged with Argon to prevent condensation or fogging.
Deep Water LOPC
The Deep Water LOPC maintains the same sampling ability of the standard LOPC, but is designed and manufactured from Titanium for deep water environments.
6000m and 3400m models available.
Deck Unit
The LOPC Deck Unit has been upgraded to a more user-friendly design. The new model is a 19”, (3U) rack mountable unit with better access to controls and connection points.
LOPC 11/04i
Options
11-50 Thornhill DriveDartmouth, Nova Scotia
Canada B3B 1S1Tel: 902-468-2928Fax: 902-468-1388
Wide Tunnel
The wide tunnel is an interchangeable option to the standard LOPC tunnel that allows a user to sample larger water volumes (2.5x), which is especially useful in areas of low plankton concentrations. The LOPC can be factory calibrated to accept both tunnel sizes so that the tunnels are field changeable.
Sample Circulator
The Sample Circulator is a self contained, closed-loop, water circulation system with continuous flow and automatic level control. Accompanied by the LOPC, the Sample Circulator becomes a useful tool for processing new or archived samples. The samples are introduced into the system via the sampling chamber and are collected by filters for recovery. The system is packaged in a durable shipping container which doubles as a free-standing structure.
Deck Unit Multiplexer
The Deck Unit Multiplexer is a user installable option with the standard Deck Unit. It allows the collection of external data streams for integration into the LOPC data files. Possible uses include: GPS/NMEA input, CTD input (SBE 19, SBE19plus, SBE911, etc.).
Flow Tube and Stand
Combining an LOPC with an external flow tube and stand allows the conversion of a standard (towed) LOPC to function as a Lab LOPC. The LOPC becomes a dual-use instrument (towed and lab), that can also be used with the Sample Circulator (see above). Recommended for low humidity use only.
Data Logger
The Data Logger allows autonomous data collection by powering the LOPC with the on-board battery supply and controlling data acquisition for up to 12 hours (dependent on sensor package). Data is collected in a standard format that can later be viewed with the LOPC Interface Software. A USB interface is available for fast data offload.
LOPC 11/04i