Sequoia LISST-VSF User Manual
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Sequoia LISST-VSF User Manual

Multi-angle polarized light scattering meter
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LISST-VSF
Multi-angle Polarized Light
Scattering Meter
User's Manual
Version 3.0
(December 2016)

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  • Page 1 LISST-VSF Multi-angle Polarized Light Scattering Meter User’s Manual Version 3.0 (December 2016)
  • Page 2 (This page intentionally left blank.) LISST-VSF User’s Guide...
  • Page 3  Data from small and large angles in a single data stream, including depth, temperature, date and time.  Approximately 4 sec. per measurement set [involves 2 turns of Eyeball with vertical, and horizontal laser polarization].  This document is copyrighted by SEQUOIA SCIENTIFIC, INC. LISST-VSF User’s Guide...
  • Page 4 Dimensions 10 cm (4”) diameter, 52 cm (20.5”) long including handle Weight: 6.5 kg (14.3 lbs]) in air; 2 kg (2.2 lb) in water Voltage: 14.4 V nominal; 16 V fully charged; 12 V min. operating. Capacity: 14 Ahr, 200 Whr. LISST-VSF User’s Guide...
  • Page 5 Welcome to the LISST-VSF! Using this manual This manual is divided into two sections. Section One contains an introduction to the LISST-VSF instrument and the principles of its operation. Section Two provides instructions for operation Section Three provides instructions on programming.
  • Page 6 Waste Electrical and Electronic Equipment Smaltimento di apparecchiature elettriche ed elettroniche da rottamare LISST-VSF User’s Guide...

  • Page 7: Table Of Contents

    APPENDIX A: METHOD OF EXTRACTING P11, P12 AND P22 ...........42 APPENDIX B: MATLAB SOFTWARE ..................45 APPENDIX C: OBSERVATION ANGLES, DATA FORMAT AND VARIABLE NAMES ..46 APPENDIX D: CONNECTOR PINOUTS FOR LISST-VSF ...........48 APPENDIX E: LISST-VSF ACCESSORIES ................51 WARRANTY ..........................52 LISST-VSF User’s Guide...
  • Page 8 (This page intentionally left blank.) LISST-VSF User’s Guide viii...

  • Page 9: Section I: Lisst-Vsf Instrument

    Thank you for purchasing a LISST-VSF instrument, and congratulations on your new purchase. The LISST-VSF delivers a powerful suite of measurements for marine optical scientists, all from one package. It delivers the Volume Scattering Function (VSF) from small forward angles to wide angles, depolarization parameters, and the beam attenuation coefficient c.
  • Page 10 For larger angles, and to measure the VSF and depolarization components, it is necessary to measure the intensity and polarization state of the scattered light. The LISST-VSF employs a single linearly polarized laser and two PMT detectors. One PMT measures scattered light into perpendicular polarization and the other into parallel polarization.
  • Page 11 Appendix A. The physical layout of the instrument is shown in Fig.2 below. The Instrument . The endcaps on Figure 2: The internal arrangement and housing of the LISST-VSF this instrument are NOT to be opened without consent of the factory. Electro-Optic Components The instrument employs a single 515nm TE-cooled diode laser.
  • Page 12 VSF from Mie theory. The expected Detailed Data measurement from, say, single size polystyrene beads can be computed view using this simulation for comparison with actual data. See the data processing section for detailed processing steps. LISST-VSF User’s Guide...
  • Page 13 Example Results We show below VSF obtained with 0.5 and 25-micron polystyrene spheres, contrasted with Mie theory. Note that due to the 1-deg resolution of the LISST-VSF, the very high resolution oscillations for 25mm particles are averaged. Use in The instrument can be used in the laboratory, using a provided water Laboratory or chamber, or in the field.

  • Page 14: General Precautions

    CAUTION LASER RADIATION permanent damage. Do Not Open You should never have to open the LISST-VSF pressure case. Doing so Instrument Cases may void the Manufacturer’s Warranty! Connecting Cables Always connect cables to the instrument first, then connect the other end to the battery pack, bench-top power source, or PC.

  • Page 15: I.3 Quick Start

    5. Battery Charger 6. Power Supply 7. Power Supply adapter cable (adapts to 3-pin underwater female) 8. Instrument Stands (2 for LISST-VSF, 2 for battery pack), for use on laboratory bench. 9. USB memory card with software and electronic documents 10.
  • Page 16 The Communication connector is the only 5-pin connector. It is located below the engraved serial number. After removing the cap install the cable making sure that proper alignment of the cable is maintained, so that the connectors are not bent. LISST-VSF User’s Guide...
  • Page 17 NOTE: An improved test chamber for laboratory and flow-through use is in development. Connect Power Connect the LISST-VSF to the battery pack with the supplied underwater cable, or to the power supply provided with the instrument. Start LISST-VSF Launch the software by double-clicking the icon on your desktop.
  • Page 18 Window. Your new file should then appear in the list box under ‘Files on LISST.’ Choose an offload directory using the controls on the right side of the window. Then highlight the .VSF file and press the green arrow to download the file. LISST-VSF User’s Guide...
  • Page 19 Downloading Data From the main window of the LISST File Transfer software you will see a listing of files stored onboard the LISST-VSF and a listing of files in a local directory. Use the controls on the right of the window to select an offload directory.

  • Page 20: Section Ii: Operation

    1. Instrument mounting, storage and maintenance 2. Charging and Connecting the NIMH battery pack 3. Bench-testing and collecting background data 4. Offloading and erasing data files from instrument memory 5. Recording and storing a sample data file 6. Data Processing LISST-VSF User’s Guide...

  • Page 21: Ii.1 Instrument Mounting, Storage And Maintenance

    Sequoia. See Appendix H for: Accessories. Long-Term The LISST-VSF is a sensitive instrument. When not in use for longer periods, Storage the instrument should be stored in its shipping case. Clean and dry the instrument before storage.

  • Page 22: Ii.2 Charging And Using The Battery Pack

    Voltage: 14.4 V nominal; 16 V fully charged; 12 V min. operating.  Capacity: 14 Ahr, 200 Whr. The battery pack connects to the LISST-VSF through a 3-pin wet-mateable connector (MCBH-3-FS). The NiMH cells in the battery can be damaged by discharging to too low a voltage.
  • Page 23 It is normal for the battery pack to become warm during extended charging. . NOTE: do not attempt to “top off” the battery by starting another charge after the charger stops. This will overheat the battery and reduce its capacity. LISST-VSF User’s Guide...

  • Page 24: Ii.3 Bench Testing And Collecting Background Data

    II.3 Bench Testing and Collecting Background Data Bench Setup The LISST-VSF instrument should be set up on the two white plastic mounting blocks, placed roughly between the middle of each pressure case on either side of the eyeball. Make sure that you do not add bending moments on the pressure case.
  • Page 25 Communication > Open Terminal. Scattering File The LISST-VSF ring data is sensitive to ambient light. Therefore, it is suggested that the sample volume be covered with a felt sheet or other opaque barrier during sampling. When ready, type the command: L-VSF:>...
  • Page 26 ‘Overlay Data From Another File…’ button. The file you select will appear in red. Use the dropdown box in the upper right to view comparisons of ring or eyeball data. Factory backgrounds are provided on your USB card. LISST-VSF User’s Guide...

  • Page 27: Ii.4 Offloading And Erasing Data Files From Instrument

    The file names will remain the same as on the compact flash card. A status bar will be displayed for each file offloaded. Text in the lower left corner will display the current file being offloaded. LISST-VSF User’s Guide...
  • Page 28 After pressing yes, the files will be deleted. This can take several minutes if a large number of files has been selected for deletion. WARNING: Once a file has been deleted it cannot be recovered. Make sure that the file has been properly offloaded before deleting any files. LISST-VSF User’s Guide...

  • Page 29: Ii.5 Recording And Storing A Sample Data File

    Stop Condition: Fixed Number Stop at 20 samples This configures the LISST-VSF to collect 20 sets of scattering data (each including both laser polarization states). The number specified with the PD command can be changed to collect a different number of sets.

  • Page 30: Ii.6 Data Processing

    The parameter  is the ratio of two photomultiplier sensitivities. If you would like the software to estimate the value of alpha, put an empty array in the alpha input (“[ ]”). We recommend using automatic route. LISST-VSF User’s Guide...
  • Page 31 Step by Step The following sub-sections describe a more detailed processing of LISST-VSF Data data. Although these steps are identical to the sequence in lisstvsf_makep.m it Processing gives you access to intermediate results.
  • Page 32 When this script is run, the Matlab GUI will appear. In this 4-window plot, you can display all raw data. You can even overlay data up to 4 different files. Since a data file has not been selected yet, the plots will be empty. LISST-VSF User’s Guide...
  • Page 33 To overlay parameters from 2 or more files, press the ‘Overlay Data From Another File’ button (lower left). You can overlay data from up to four different files. This feature is especially useful to compare a background file to the factory background, or eyeball backgrounds. LISST-VSF User’s Guide...
  • Page 34 90 which is expected for pure water scattering Any of the parameters selected in this manner can be viewed in this GUI. Data from up to 4 files can be overlaid in this manner. LISST-VSF User’s Guide...
  • Page 35 This function contains calibration information specific to your instrument. The instrument serial number (SN) is passed as the input and the function returns a structure containing the calibration values. This function is used by the lisstvsf_makep function. calfact = lisstvsf_getcal(SN); LISST-VSF User’s Guide...
  • Page 36 The code is well commented. It is here that the jump in lisstvsf_makep.m raw data at 40 (seen with the view_rawfile command) is removed; laser power variation is normalized out, sample volume stretching is compensated, etc. LISST-VSF User’s Guide...
  • Page 37 2. It is possible to view each datafile using the lisstvsf_view GUI or lissvsf_readdat functions. 3. The break in p22 at 45 and 135 is caused by the nature of these data with the rotating eyeball (explained in Appendix A). LISST-VSF User’s Guide...

  • Page 38: Section Iii: Instrument Communication And Programming

    8 data bits, No parity, and 1 stop bit. Data file transfer is normally done using a YMODEM transfer at 115K baud. Two Letter Once connected to the LISST-VSF, type HE at the L-VSF:> prompt to see a Commands list of commands, and read the following sections for complete details.

  • Page 39: Programming

    The details of each condition are described below. Depth Start The built-in depth sensor of the LISST-VSF is used to check the current depth to determine if the desired start depth has been exceeded. The instrument is powered up and 5 measurements of the depth are averaged over a two-second period.
  • Page 40 The details of each condition are described below. Depth Stop The built-in depth sensor of the LISST-VSF is used to check the current depth to determine if it is less than the desired Stop depth. averaged depth from the last sample acquired is used as the current depth.
  • Page 41 LISST-VSF User’s Guide...

  • Page 42: Command Details

    Example: ST 01/05/2005 21:05:03 Autostart Setting Store Current Settings as Default Reset Depth Sensor Offset Acquisition/Action Commands DL filename Delete File Start Data collection using current parameters Collect background scattering and store in a file LISST-VSF User’s Guide...
  • Page 43 Note that the laser and eyeball motor will run briefly in order to measure the supply voltage accurately. Example: input: DS output: LISST-VSF Current Status and Settings Serial number = 1425 Firmware Version 0.920 Jul 23 2012 17:34:17 . [ various parameters and settings] Battery Voltage is 10.75...
  • Page 44 LISST-VSF User’s Guide...
  • Page 45 Start Condition: Depth Start at 3 meters input: TD 12/31/05 23:59:59 (if Start Condition = 2 (Time/Date Start)) output: New Start Condition data = 12/31/05 23:59:59 Start Condition: Time Start at 12/31/05 23:59:59 Input: TD 2 (if Start Condition = 5 (Delay Start)) LISST-VSF User’s Guide...
  • Page 46 Description: The sample interval is the minimum number of seconds between two consecutive samples. Note that a complete sample of ring and eyeball data from the LISST-VSF requires 3 to 4 seconds. Therefore SI values lower than 4 will be ignored.
  • Page 47 Current Date/Time: Wednesday, August 17, 2011 12:24:14 Current Day of the Year: 229 Cautions: If you change any of the settings after issuing the SD command you must reissue the SD command to save the updated settings. LISST-VSF User’s Guide...
  • Page 48 Zdddhhmm.DAT. A file of this type is required for processing LISST-VSF data. Example: Input: ZS [N] Output: <Status information during sampling> Notes: To acquire accurate background readings, the LISST-VSF must be set up with water that is completely free of particles and bubbles. LISST-VSF User’s Guide...
  • Page 49 LISST-VSF User’s Guide...

  • Page 50: Appendix A: Method Of Extracting P11, P12 And P22

     is the relative gain of the two photomultipliers. is not known a priori, it is determined from data. Determining the Relative Gain of the Two Photomultipliers:  is estimated from the convenient result that at and equations B2a and B2b reduce LISST-VSF User’s Guide...
  • Page 51 Experienced MATLAB users will know how. We will provide a description shortly. These equations are implemented in the MATLAB function lisstvsf_makep. Absolute Calibration of P11: Since P12 and P22 are conventionally displayed after normalization by P11, only the absolute calibration of P11 is required. LISST-VSF User’s Guide...
  • Page 52 VSF. The latter is absolutely calibrated from measured responsivity (A/W) of the silicon ring detectors, as reported in: Agrawal YC, Mikkelsen O. A (2009): Empirical forward scattering phase functions from 0.08 to 16 deg. for randomly shaped terrigenous 1-21 µm sediment grains. Optics Express 17:8805–8814. LISST-VSF User’s Guide...

  • Page 53: Appendix B: Matlab Software

    ANGLE. The ‘on’ and ‘off’ refer to PMT outputs in digital counts summed for several cycles of laser chopping. See Appendix D for full details. variable name laser polarization PMT polarization perpendicular PMT1: parallel perpendicular PMT2: perpendicular parallel PMT1: parallel parallel PMT2: perpendicular LISST-VSF User’s Guide...

  • Page 54: Appendix C: Observation Angles, Data Format And Variable Names

    3.0977 2.8533 3.0977 3.6525 3.3651 3.6525 4.3053 3.9677 4.3053 5.0725 4.6769 5.0725 5.9727 5.5103 5.9727 7.0267 6.4882 7.0267 8.2571 7.6332 8.2571 9.6876 8.9698 9.6876 11.3413 10.5237 11.3413 13.2388 12.3202 13.2388 15.3941 14.3814 Angles 33 to 182 6-155 LISST-VSF User’s Guide...
  • Page 55 Pressure, in digital counts; each count is 0.01m Temperature in units of 1/100 of 1 (Day*100 + Hour) at which data taken (Minutes*100 + seconds) at which data taken 41-790 150 sets of [ angle, PMT1_on, PMT1_off, PMT2_on, PMT2_off LISST-VSF User’s Guide...

  • Page 56: Appendix D: Connector Pinouts For Lisst-Vsf

    Appendix D: Connector Pinouts for LISST-VSF The LISST-VSF has 3 separate underwater connectors: A 5-pin, a 6-pin, and a 3-pin connector. The photograph shows the placement of each connector. The following text describes the detailed wiring for each connector. xxx...
  • Page 57 Connector Manufacturer: Impulse Enterprise, Inc. San Diego, CA, USA Connector Part Number (Bulkhead): MCBH (WB)-5-MP Stainless Steel Mating Cable Part Number: MCIL-5-FS xxx Connector Pin # Serial Ground No Connection Serial Ground Serial Out (to DB-9 Pin 2) Serial In (to DB-9 Pin 3) LISST-VSF User’s Guide...
  • Page 58 Connector Manufacturer: Impulse Enterprise, Inc. San Diego, CA, USA Connector Part Number (Bulkhead): MCBH (WB)-3-MP Stainless Steel Mating Cable Part Number: MCIL-3-FS xxx Connector Pin # Power Ground Custom NIMH Battery Charger Input, 14.8V nom. Power Out (12V nom. 9V-16.9V actual) LISST-VSF User’s Guide...

  • Page 59: Appendix E: Lisst-Vsf Accessories

    Appendix E: LISST-VSF Accessories a. USB b. Manual c. Sediment Samples d. Spare O-rings e. Mounting Clamps (4 sets) f. Lexan Sheet for Background chamer g. Background chamber clamps (2) h. Communications Cable i. Battery Cable j. Battery Charger k. Power Supply l.

  • Page 60: Warranty

    If, during the twelve months after delivery (the “Warranty Period”), any Product does not comply with the warranties set forth in 1(a) and 1(b) above, SEQUOIA will, at its option, either (a) repair the Product, (b) replace the Product, or (c) refund the purchase price paid by Customer to SEQUOIA for the Product; provided that Customer gives SEQUOIA written notice of the noncompliance within the Warranty Period and ships the Product to SEQUOIA within one month after the end of the Warranty Period.
  • Page 61 SEQUOIA) will in no event exceed the purchase price paid by Customer to SEQUOIA for such Product. Further, SEQUOIA will not be liable for, or be in breach of or default on account of, any delay or failure to perform as a result of any cause, condition or circumstance beyond SEQUOIA's reasonable control.
  • Page 62 Document History Revision Date Description Author 2012/08/28 Draft document YCA/WHS/RS 2013/03/08 Updated for non-AOM units RS/WHS Update for GT prism models, auto PMT,… 2016/12/11 YCA/DD/TL LISST-VSF User’s Guide...

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