Sequoia LISST-AOBS, User Manual

Page 1: ...vember 2021 Describes LISST AOBS Version 2 serial numbers 6246 and higher For earlier Version 1 LISST AOBS models see manual version 1 Sequoia Scientific Inc 2700 Richards Road Suite 107 Bellevue WA 9...

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Page 3: ...rectly from Sequoia Please be sure to include the instrument serial number with any correspondence A list of local Sequoia distributors can be found at our website http www sequoiasci com about contac...

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Page 5: ...abels on WQDataLIVE 5 SDI 12 OPERATION DETAILS 7 Overview 7 Addressing 7 Sampling and averaging 7 Control of the anti fouling wiper 7 SDI 12 COMMAND REFERENCE 8 RS 232 OPERATION 9 Overview 9 USB power...

Page 6: ...ng LISST AOBS Data 23 CONNECTION DETAILS 24 Pin functions 24 Male connector numbering 24 Female mating connector numbering 24 Cables 24 SPECIFICATIONS 25 APPENDIX HOW THE LISST ABS WORKS 26 REVISION H...

Page 7: ...OBS concentration Super Turbidity in mg liter a combination of the ABS and OBS measurements as described in Pairing ABS with turbidity on page 22 Data interface and logging options LI T AOBS has two d...

Page 8: ...er if applicable the LISST AOBS will start sending one data sample per second via RS 232 and continue indefinitely The host data system is not required to send any commands in this mode The free runni...

Page 9: ...determine to exact wiring depending on the mating device General Use and Care Do not use abrasives or harsh solvents for cleaning These could damage the plastic exterior Use special caution with the...

Page 10: ...10 minutes but can be changed through the X2 s Wi Fi interface or through the CONNECT software Data storage transmission The logging of LISST AOBS data on an X2 is controlled by a script provided wit...

Page 11: ...other SDI 12 devices to the logger you must ensure that they have unique addresses The LISST AOBS address can be changed but the X2 logger detection script requires it to be within the range 0 to 9 I...

Page 12: ...do this 1 On your WQDataLIVE project s dashboard pull down the Admin menu and select Settings 2 On the Settings page find the Parameter Settings section 3 Under Parameter Settings click on the name of...

Page 13: ...he LISST AOBS can be sampled every 2 to 3 seconds using the SDI 12 M command However we recommend collecting 30 second averages in most cases to smooth the natural variability created by turbulent mot...

Page 14: ...300 seconds Run wiper then start measurement aM5 aM6 aM7 aM8 aM9 Run the wiper then average for 30 seconds Run the wiper then average for 60 seconds Run the wiper then average for 120 seconds Run the...

Page 15: ...the cable to the USB port which will power the LISST ABS 3 connect the Turbidity Plus to the Y cable Port parameters The RS 232 port parameters are 9600 baud 8 bit data no parity one stop bit no flow...

Page 16: ...S OBS and AOBS values Example LISST AOBS GS 4 66e 01 1 004 8 78e 02 LISST AOBS Start free running data Syntax GO or GO period Description Starts free running mode If a numeric period value is included...

Page 17: ...the RS 232 output Use the SL command to get the result Example LISST AOBS HS LISST AOBS Set automatic wiping Syntax OBSSET OBSI interval Description Controls whether the wiper will automatically run a...

Page 18: ...e LISST AOBS SL 4 66e 01 1 004 8 78e 02 LISST AOBS Run anti fouling wiper Syntax WI or wipe Description Runs the wiper on the Turbidity Plus The command prompt returns immediately but if you send anot...

Page 19: ...ctions to complete the instillation on your computer USB Drivers Before launching the LISST ABS software plug the USB cable into your computer If the computer has an internet connection it should auto...

Page 20: ...uter s ports To change to a different port see Settings Tools on page 18 You may also open several instances of the LISST ABS program to view data from multiple instruments Software Configuration Opti...

Page 21: ...w Y Min or Y Max You can switch back to auto scaling by deleting the values in the text boxes Plot Layout Each tab of the software shows a time series of the different AOBS measurements Concentration...

Page 22: ...16 Or they can be docked in any orientation by dragging and hovering over the main window...

Page 23: ...ng periods of time In these cases there is no need to tie up computer resources generating a plot that will not be viewed To resume plotting data uncheck the box Logging Data Logging is initiated by p...

Page 24: ...e header is followed by five columns of data date time ABS standardized concentration optical backscatter volts and total concentration mg L Settings Tools Program settings and tools are accessed by c...

Page 25: ...unicate directly with the instrument This can be useful for retrieving information about your sensor or exploring the instruments serial communication features Text from this window can be saved to fi...

Page 26: ...u to disable the automatic port searching feature If you know what port your LISST ABS is connected to you can specify the port in this window This can be useful if you are on a computer with many por...

Page 27: ...ABS User s Manual The optical measurement is provided by a Turner Designs Turbidity Plus sensor with integrated anti fouling wiper The Turbidity Plus s sensitivity to particles like that of any turbid...

Page 28: ...that the optimum pairing factor is P CABS VOBS when measured with particles of 30 m diameter and with a high enough concentration to make the clean water offset V0 negligible Put another way P should...

Page 29: ...heir contribution to the AOBS quantity Because they have different responses to particle size the ABS and OBS data can also provide insight into the particle size distribution PSD If the ratio of OBS...

Page 30: ...r is Subconn MCIL8F 1 Common 2 Supply voltage 10 to 15 V 3 Common 4 RS232 transmit from AOBS to computer 5 RS232 receive to AOBS from computer 6 SDI 12 input output 7 No connection 8 Common Common pin...

Page 31: ...75 mA o Wiper running sampling pauses 68 mA Input voltage 10 to 15 VDC maximum limited by Turbidity Plus Maximum depth 100 meters limited by LISST ABS Dimensions see drawing below Concentration measur...

Page 32: ...of acoustic backscatter The strength of the backscatter pressure P at the transducer from a range R ct is related to the outgoing pressure pulse Po the geometric spreading G R and attenuation by the c...

Page 33: ...ion The idealized relationship between ACB and sediment concentration is shown in the plot below Note that this is a log linear relationship which is helpful for analysis as well as matching the chara...

Page 34: ...ion to describe new LISST AOBS version 2 Manual version 1 3 still applies to older LISST AOBS Version 1 3 Remove incorrect warranty statement For warranty information see www sequoiasci com support wa...