Inter-Laboratory Comparison of
Calibration Procedures for Acoustic
Doppler Velocity Meters
Kirk Thibodeaux (Retired)
USGS - HIF
Background
• In March 2013 an Acoustic Workshop was
held at the U.S. Geological Survey's
Hydrologic Instrumentation Facility to
discuss and exchange information on the
testing, evaluation, and calibration of
acoustic Doppler velocity meters (ADVM)
in laboratory settings.
Background (continued)
• Groups representing Laboratory operators
that had conducted testing, or expressed a
desire to conduct testing, on acoustic
instrumentation, manufacturers, and large
end users were invited to attend.
• Representatives from 10 Laboratory
towing facilities, manufactures, and end
users were represented.
Background (continued)
• Representatives from;
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Australia (Queensland Department of Natural Resources and Mines).
Canada (Environment Canada).
Japan (International Centre for Water Hazard and Risk Management).
New Zealand (National Institute of Water and Atmospheric Research,
NIWA).
Switzerland (Federal Institute of Metrology, METAS).
The Netherlands (DELTARES).
The United States (USGS).
Ott Hydromet (Germany and US).
Teledyne RDI (US).
Hydro Systems Development, Inc (Japan).
Purpose of Workshop
• Share information on why and how each
facility tests/calibrates acoustic
instrumentation.
– Each participant was required to give a
presentation on what testing they were
conducting and/or what testing they planned
to conduct in the near future.
Purpose of Workshop
• Why do we need to test Acoustic velocity
meters in a Laboratory setting?
– We need to verify that the equipment is
working as it should when purchased.
– We need to verify that the equipment is
working as it should after being deployed.
– We need to track the performance of the
equipment over time.
– And we need to catch..
7/28/2001
10/11/2001
12/25/2001
3/10/2002
5/24/2002
8/7/2002
10/21/2002
1/4/2003
3/20/2003
6/3/2003
8/17/2003
10/31/2003
1/14/2004
3/29/2004
6/12/2004
8/26/2004
11/9/2004
1/23/2005
4/8/2005
6/22/2005
9/5/2005
11/19/2005
2/2/2006
4/18/2006
7/2/2006
9/15/2006
11/29/2006
2/12/2007
4/28/2007
7/12/2007
9/25/2007
12/9/2007
2/22/2008
5/7/2008
7/21/2008
10/4/2008
12/18/2008
3/3/2009
5/17/2009
7/31/2009
10/14/2009
12/28/2009
3/13/2010
5/27/2010
8/10/2010
10/24/2010
1/7/2011
3/23/2011
6/6/2011
8/20/2011
11/3/2011
1/17/2012
4/1/2012
6/15/2012
8/29/2012
11/12/2012
1/26/2013
4/11/2013
6/25/2013
9/8/2013
11/22/2013
2/5/2014
4/21/2014
7/5/2014
9/18/2014
% Error
Percent Error at 1 Second Data
(18 cm/s)
4.00%
3.00%
2.00%
1.00%
0.00%
-1.00%
-2.00%
-3.00%
-4.00%
Matrix Date
18 cps
Manufacturer's Cal Limits
Accuracy Statement
Depth Reading Deviation
0.20
Deviation from Correct Depth (ft)
0.15
0.10
0.05
0.00
-0.05
-0.10
1.0
2.0
3.0
Depth (ft)
4.0
5.0
Distance Made Good - Each Transect
(2012-04-12) [Large Acoustic Tank]
3.0%
2.0%
Percent Error
1.0%
0.0%
-1.0%
-2.0%
-3.0%
1
2
3
4
Run Number
OSW Limits
Equip DMG Limits
Beams 1 and 2
Beams 4 and 3
Beams 2/3 and 1/4
Mean - All Runs
Beams 1/3 and 2/4
Outcome of Workshop
• Proposal to organise a worldwide interlaboratory comparison which should verify
and assess calibration procedures for
acoustic Doppler velocity meters (ADVM)
in the velocity range from 0.05 m/s to 1.50
m/s.
– SonTek FlowTracker (S/N P1515)
– Ott ADC (S/N 231360)
Outcome of Workshop
• Laboratories from 8 countries agreed to
take part in the comparison.
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Australia (NRM),
Austria (BAW),
Canada (CCIW),
Germany (OTT),
New Zealand (NIWA),
Switzerland (METAS),
The Netherlands (DELTARES), and
The United States (USGS)
Comparison Test Procedure
• Developed by Switzerland.
– Each participating Laboratory to use standard
(group) protocol and their normal testing
procedures, if they had any.
– Group testing data to be compared.
Comparison Test Procedure
• Group Testing.
– Mounting –
• FlowTracker
Attached to a mockup of a USGS standard top
setting wading rod with a “J” bracket (supplied by
the USGS).
Comparison Test Procedure
• Group Testing.
– Mounting –
• FlowTracker
Attached to a mockup of a USGS standard top
setting wading rod with a “J” bracket (supplied by
the USGS).
Comparison Test Procedure
• Group Testing.
– Mounting –
• FlowTracker
Attached to a mockup of a USGS standard top
setting wading rod with a “J” bracket (supplied by
the USGS).
• ADC
Attached to a 20 mm cylindrical rod (supplied by
the testing Laboratory).
Comparison Test Procedure
• Towing speeds;


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

0.05 m/s
0.18 m/s
0.385 m/s
0.50 m/s
1.0 m/s
1.5 m/s
Status of Testing
• Shipping problems, or laboratory
problems, prevented all Laboratories from
conducting the group testing by the
scheduled completion date.
• Six of the 8 participating Laboratories have
conducted the tests.
• Five have collected a full set of data.
• Four have forwarded their collected data
for analysis.
Preliminary Test Results
• Data presented anonymously.
• Towing tanks ranged from;
– 1.2 m wide by 1 m deep by 24.4 m long to
– 4 m wide by 2.4 m deep to 140 m long.
• Seeding materials;
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Glass spheres
Polyamide spheres
Ytong (Cellular concrete)
Bentonite clay
Preliminary Test Results
SonTek FlowTracker (S/N P1515)
10.0%
8.0%
Meter Reading Error (%)
6.0%
4.0%
2.0%
0.0%
-2.0%
-4.0%
-6.0%
-8.0%
-10.0%
0.0
0.2
Tank 1
0.4
Tank 2
0.6
0.8
Tow Speed (m/s)
Tank 3
Tank 4
1.0
1.2
1.4
FlowTracker Limits
1.6
Preliminary Test Results
Ott ADC (S/N 231360)
8.0%
6.0%
Meter Reading Error (%)
4.0%
2.0%
0.0%
-2.0%
-4.0%
-6.0%
-8.0%
0.0
0.2
0.4
Tank 1
0.6
Tank 2
0.8
Tow Speed (m/s)
Tank 3
1.0
Tank 4
1.2
ADC Limits
1.4
1.6
Future Testing
• Continue testing at the Laboratories that
have not conducted the testing.
• Retest at the Laboratory that had
problems during it’s first round of testing.
• Compile and analyze the collected data
from all participating Laboratories and
publish the results.
Acknowledgements
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Dr. Marc de Huu and Beat Wüthrich, Switzerland.
Chris Appleby and Andrew Willman, New Zealand
Elizabeth Jamieson and Paul Campbell, Canada
Marinus Schroevers, The Netherlands
Raymond Alford, Australia
Silke Kainz, Austria
Atsuhiro Yorozuya and Tadashi Kitsuta, Japan
Fabian Kratz - OTT Hydromet, Germany
Christel Valentine - HACH Hydromet, US
Ian Cassimatis - Teledyne RDI, US
Questions?