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Routine Field Techniques. Streamflow Record Computation using ADVMs and Index Velocity Methods Office of Surface Water. Overview. Overview. Tip Sheets in IV T&M Report - Appendix 2. Download Data. Download datalogger /DCP data Download ADVM internal recorder data. Connect to ADVM.
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Routine Field Techniques Streamflow Record Computation using ADVMs and Index Velocity Methods Office of Surface Water
Download Data • Download datalogger/DCP data • Download ADVM internal recorder data
Connect to ADVM • Connect ADVM cable to computer through 9-pin serial port or USB-serial adapter • Open ADVM software and select communication settings
Changing Between SDI-12 and RS-232 • SonTek ADVMs have a jumper plug • Plug together when communicating using computer • Unplug when in SDI-12 mode and controlled by DCP Plugged In = RS-232 Mode Unplugged = SDI-12 Mode
What to Look For? • Focus on problems that could be resolved in field • Obstruction in sampling volume • Change in ADVM orientation • Sediment or biofouling on beams • Beam failure • Thermistor failure • Change in cell end due to reduced scatterers or other problem • ADVM stopped working • Should be a brief review to look for major problems! • More thorough review will be done in office
Erase Recorder • Again, ensure data file is complete and saved to your computer • Rename file according to your Office’s QA Plan • Recommend erasing recorder each time to reduce chance of filling recorder and losing data • CAUTION: Once erased, data cannot be recovered!
Record a Log File • Capture current configuration settings and any changes to settings by recording a “log” file • Changes to measurement volume • Time/date before and after clock sync • Changes to averaging period/measurement interval • In SonUtils, go to File – Open Log File. Click “Show….” buttons to capture current settings • Log file will capture all commands entered in software until you close file • Archive when back in the office
Check and Sync Clocks • Check and, if needed, sync clocks in DCP, ADCP, and ADVM • Within 1-2 seconds Correct Time: www.time.gov http://tf.nist.gov/
Check ADVM Temperature • Per OSW Memo 2010.07….An independent water temperature measurement must be made and documented during each site visit to an index velocity station. • Temperature must match within 2o C • Make comparison beside ADVM if at all possible
Beam Check • Collect a beam check • Turn averaging “on” in SonTek ADVMs • Record a minimum of 50 pings
Beam Checks – Look for Problems • Obstructions? • Sidelobe problems? • Signal Amplitudes 10-20 counts above noise level at Cell End? • Changing Cell End? • Signal Amplitudes similar for each beam?
Examples of Problems What would you do about these problems in the field?
Clean ADVM • Remove biofouling, debris, sediment, ice • Use soft bristle brushes where possible
Check ADVM Alignment • Has mount moved? • Has ADVM moved on mount? • How could you tell?
Another Beam Check • Perform another beam check if: • First one showed a problem • Cleaning removed a lot of biofouling or sediment • ADVM alignment was altered
Configure ADVM For Q Measurements • Change averaging interval and measurement period of ADVM to 1 minute during Qms • Change in ADVM and allow to record internally during Qm • May also need to change stage readings to 1 minute
Re-Connect With ADVM • Re-connect and download 1-minute data • Change averaging period and measurement interval back to regular settings • Any other configuration changes? • Remember to record a log file!
Re-Deploy ADVM • May need to set a start date/time in ADVM • If controlled by datalogger, put in SDI-12 mode • Example for SonTek ADVM…. • Unplug jumper! • Make sure ADVM and DCP are working
Documentation • SWAMI • IV Gage Inspection Form
SWAMI • As of June 2012, SWAMI does not allow for any field entry of index-velocity specific information for discharge measurements • Cannot use SWAMI to calculate percent differences • Index-velocity ratings are not available to view • If index-velocity for a measurement is calculated in the field it can be put into a comment box for later entry into SiteVisit • A request enhancement has been submitted by the HAWG for a separate index-velocity inspection tab and integration into the discharge measurement screens
SWAMI • If your index meter is set up in SiteVisit, you can enter readings same as a stage gage