Related Manuals for Sequoia LISST-Tau
Summary of Contents for Sequoia LISST-Tau
- Page 1 LISST-Tau High-Precision Transmissometer User’s Manual Version 1.35 November, 2021 Store Software USB Card Here 2700 Richards Road, Suite 107 Bellevue, WA 98005-4200 Tel: +1 (855) 753-3313...
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- Page 3 LISST-Tau High-Precision Transmissometer Technical assistance For technical assistance please contact your local Distributor or Sequoia. Please be sure to include the instrument serial number with any correspondence. Warranty See Sequoia Scientific’s standard warranty terms at www.sequoiasci.com/support/warranty Sequoia Scientific, Inc. contact information:...
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Page 5: Table Of Contents
UTORIAL OPERATION DETAILS ......................5 ....................6 TEP BY ROCEDURES Installing LISST-Tau Software ..................6 Establishing Communication with the LISST-Tau ............7 Using the LISST-Tau software..................9 Cleaning Windows ......................13 Clean-water Baseline Measurement (Calibration) ............14 ..................... 15 NSTRUMENT OMMUNICATION ...................... - Page 6 This page intentionally blank. LISST-Tau User’s Manual Table of Contents Page vi...
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Page 7: Introduction And Tutorial
2000 meters. LISST-Tau generates a beam of light from an LED, formed by a lens into a uniform, low-divergence beam. The LED is modulated at 1000 Hz. 532-nm LISST-Tau models also have a spectral filter to control the spectral bandwidth. -
Page 8: Quick Start Tutorial
LISST-Tau see Instrument Communication on page 15. Once the cable is operating properly, you should be able to place a piece of paper in the path of the LISST-Tau and see the green (532 nm) or red (650 nm) beam. 3: Install LISST-... - Page 9 Do not remove the memory card from your computer until the installation is complete. 4: Start LISST- Start the LISST-Tau software by selecting the shortcut the installer Tau Application placed on your desktop. Upon starting the LISST-Tau software will...
- Page 10 Step 8: Ready The LISST-Tau is now ready to deploy. You can disconnect it from the to Deploy computer at any time and mount it to the deployment system, or return it to its carrying case. Preparing for Although the LISST-Tau is robust, handle it with the care you would transport or any sensitive measuring instrument.
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Page 11: Operation Details
(e.g. command list, instrument mounting and deployment). General • LISST-Tau is a sensitive optical instrument - please handle it Precautions gently as you would handle an expensive camera. • Critical alignment may be disturbed if the instrument is subjected to shock or rough handling. -
Page 12: Step By Step Procedures
C. Step by Step Procedures Installing LISST-Tau Software The Sequoia-supplied LISST-Tau software for Windows is used to configure the LISST-Tau and downloading data. STEP ACTION RESULT • The LISST-Tau comes with a USB memory card. Plug Installer was found on... -
Page 13: Establishing Communication With The Lisst-Tau
Establishing Communication with the LISST-Tau Establish communication with LISST-Tau using the supplied software and USB cable. Communicating with the LISST-Tau via the provided software should be automatic. Should there be a problem you can use these step-by-step instructions to troubleshoot the problem. - Page 14 • If using an alternate software or instrumentation to communicate with the LISST-Tau make sure that the serial port settings are set to the following: o Baud Rate: 19200 o 8 Bits, no parity, 1 stop bit For example code for parsing the serial data string that is output by the instrument, see Appendix C: Parsing Serial Data String on page 25.
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Page 15: Using The Lisst-Tau Software
Using the LISST-Tau software Introduction The LISST-Tau software is a simple tool used for: 1. Viewing Data 2. Saving data to the computer in a text file 3. Configuring the instrument (setting the clock, measure clean- water baseline, etc.) Viewing Data... - Page 16 The clock can be set by selecting the gear icon in the lower right corner. A context menu will provide you with several options. The set clock option will sync the clock on the LISST-Tau to the current date and time on your computer.
- Page 17 The LISST-Tau command line interface can be accessed by selecting the gear icon in the lower right and selecting ‘Open Terminal’. A serial terminal window will be opened, and list of LISST-Tau commands will be displayed to the screen. LISST-Tau User’s Manual...
- Page 18 The ‘File’ and ‘Format’ items in the menu bar offer several options for formatting the displayed texted and saving or logging the command line output. LISST-Tau User’s Manual Operation Details Page 12...
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Page 19: Cleaning Windows
• Repeat the cleaning procedure if the window surface does not appear totally uniform and slightly reflective; or if there are visible debris still clinging to the windows. LISST-Tau User’s Manual Operation Details Page 13... -
Page 20: Clean-Water Baseline Measurement (Calibration)
Clean-water Baseline Measurement (Calibration) The LISST-Tau baseline is measured using very clean water at the factory and may not need to be measured in the field. However, periodic baseline measurements assure the highest measurement accuracy, and correct for factors such as scratched windows or rough handling that can affect the performance of the instrument. -
Page 21: Instrument Communication
The format and definitions of the output quantities are listed in Appendix B: Data Output Format on page 23. Using the LISST- In the LISST-Tau software you can open a terminal window to directly Tau Terminal view communications with the LISST-Tau and enter commands. When... -
Page 22: Serial Commands
DEFAULTS Syntax: Description: The LISST-Tau has various settings and modes, not described in this manual, for troubleshooting or special applications. The DEFAULTS command restores the LISST-Tau to its factory-standard operating parameters for operation as described in this manual. It does NOT affect the user calibration. - Page 23 21.79442 1.01021 Display Help Syntax: Description: Display list of commands. input: H Example: Output: LISST-Tau 1.46 (Aug 24 2021 09:57:46) ----------------------------------------------------- Display status. Start continuous data collection. [yy/mm/dd HH:MM:SS] Read or set instrument clock. [dddd] Determine the clean water calibration. Number of samples [dddd] is optional (default 10 samples).
- Page 24 LTAU1013R 2021-09-02T15:28:24 2137 31640 48122 16482… LTAU1013R 2021-09-02T15:28:26 2139 31650 48132 16481… LTAU1013R 2021-09-02T15:28:27 2140 31641 48136 16495… LTAU1013R 2021-09-02T15:28:29 2142 31648 48126 16477… LTAU1013R 2021-09-02T15:28:31 2143 31642 48135 16492… LTAU1013R 2021-09-02T15:28:32 2145 31645 48127 16481… LISST-Tau User’s Manual Operation Details Page 18...
- Page 25 LTAU1013R 2021-09-02T15:28:35 2148 31644 48118 16474… LTAU1013R 2021-09-02T15:28:37 2149 31644 48139 16494… Date TrCal TempCal CorrFunCal TrCalCorr Current 2021-07-29 13:10:30 1.115853 22.2C 1.000000 1.115853 2021-09-02 15:28:37 0.128417 21.8C 1.000000 0.128460 Ratio 8.689328 8.686362 Accept new calibration? [y|n] LISST-Tau User’s Manual Operation Details Page 19...
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Page 26: Analog Output
Many existing CTD rosettes and other profiling systems already provide for an analog-output transmissometer as one of their standard sensors. For these cases, the LISST-Tau provides an analog output on pin 6 of its main connector. -
Page 27: Appendix A: Technical Specifications
Transmission: 0.003 % (Green) / 0.005% (Red) (Standard deviation over 1 Attenuation: 0.0002 m (Green) / 0.0004 m (Red) minute, typical) Long-term stability ~0.003 %FS/hour transmission; ~0.0002 m /hr beam (6 Hour Test) attenuation LISST-Tau User’s Manual Appendix A: Technical Specifications Page 21... - Page 28 LISST-Tau User’s Manual Appendix A: Technical Specifications Page 22...
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Page 29: Appendix B: Data Output Format
Output Format Output occurs every 1 second. Values are tab delimited and each line is terminated with a <CR><LF>. Data saved by LISST-Tau software will be a TXT file in this format. The LISST-Tau supports other special-purpose data formats, which are not described here. - Page 30 Raw transmission clean-water baseline, SigLedOn – Decimal TrCal SigLedOff) / (RefLedOn – RefLedOff) e. g. 1.30319. 0.00001 Decimal TempCal Temperature of clean-water baseline, e. g. 21.01677 0.00001 LISST-Tau User’s Manual Appendix B: Data Output Format Page 24...
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Page 31: Appendix C: Parsing Serial Data String
Appendix C: Parsing Serial Data String Below is pseudo code that shows how the serial data string can be parsed into individual variables. This is how the LISST-Tau windows program captures and displays real time data from the LISST-Tau instrument. -
Page 32: Appendix D: Electrical Connections
SubConn MCIL6F Contact Function number Ground RS-232 Data In (to LISST-Tau from computer) Reserved for future use Power In (8 to 24V) RS-232 Data Out (from LISST-Tau to computer) Analog output, 0 to 5V, proportional to transmission (4.5V = 100%) LISST-Tau User’s Manual... -
Page 33: Appendix E: Measurement Description
�� �� ��0 and depends on the pathlength �� through which the beam is attenuated (�� = 0.15 m for the LISST-Tau). According to Beer’s Law, the beam attenuation coefficient (units of m −1 ) is then defined as ln ( �� ) , ��... - Page 34 �� �� �������� �� �� ���� �� ( �� ) �� �� �� �� ��������,�� �� Beam attenuation for the sample is then calculated: �� = − ln(�� ���� ���� �� LISST-Tau User’s Manual Appendix E: Measurement Description Page 28...
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Page 35: Revision History
Add “model variant” character to serial number in output format. Version 1.31 April 16, 2021 Version 1.3 Revised data format; minor edits and formatting. April 8 2021 Version 1.2 Initial public release. March 2021 LISST-Tau User’s Manual Revision History Page 29...
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