Magnetics Business & Technology - July/August 2021 - 24

PRODUCT NEWS
Teledyne Float Uses Induced Electric Currents to Measure Ocean Speeds
Ocean electric fields are caused by water currents, and depend
on two facts: saltwater is electrically conductive, and there is a
background Earth's magnetic field. Saltwater moving in the magnetic
field acts like a battery and generates an electric field. This
can be seen in the diagram, where moving sea water generates
the electric field from one side to the other. This in turn creates
an electric current that completes a circuit by returning through
the slower moving, bottom water and weakly conductive bottom
sediment. Measuring this electric current allows the speed of the
moving sea water to be calculated.
Knowing the speed of ocean waters can be important to understanding
major weather events. A cleverly designed spinning
float from Teledyne Webb Research accomplishes the task and
can transmit its data from remote seas to scientists looking for
answers.
The company's APEX-EM float directly measures water motion
through induced electric currents. Electric fields in the ocean
create electric currents, which can be measured by the float to
determine the speed of moving sea water in fine detail, explains
Hugh Fargher, APEX applications engineer, who notes that
the floats are increasingly being deployed in ocean monitoring
programs.
The measured electric current depends on both the ocean water
velocity and depth, together with an offset from the depth averaged
velocity. In practice, GPS positions taken at the surface
give the underwater displacement and provide an estimate for
this offset velocity. The float also rotates as it profiles to counter
the offset potential of the actual electrodes used by the APEXEM
float to measure the electric field. This allows measurement
of the electrode offset to be separated from the weaker field
created by the moving seawater. The technology is the result of a
collaboration between Teledyne Webb Research and the Applied
Physics Laboratory at the University of Washington.
APEX stands for " Autonomous Profiling Explorer " . The company
makes a range of the floats, providing a platform for a variety of
sensors, drifting with the ocean current while descending and
ascending between the surface and some predefined depth, all
the time taking sensor measurements which are then telemetered
back to a data-server via satellite. The floats can also be
deployed by aircraft using parachutes, which makes them ideal
for exploring areas that can be difficult to access.
Based in North Falmouth, Massachusetts, Teledyne Webb
Research designs and manufactures scientific instruments for
oceanographic research and monitoring with a focus on extended
observations over both time and space. It specializes in three
areas of ocean instrumentation: neutrally buoyant, autonomous
drifters and profilers (10,000 to date), autonomous underwater
gliding vehicles (900 to date), and moored underwater sound
sources. The systems are core to several major ocean monitoring
programs. For more info, see www.teledynemarine.com.
24 Magnetics Business & Technology * July/August 2021
www.MagneticsMag.com
http://www.teledynemarine.com http://www.MagneticsMag.com

Magnetics Business & Technology - July/August 2021

Table of Contents for the Digital Edition of Magnetics Business & Technology - July/August 2021

Magnetics Business & Technology - July/August 2021
Editor’s Choice/ Features
Major Automakers Transform Design & Manufacturing Operations on Accelerated Path to e-Propulsion – Part 2 of 2
Luxury Auto Maker Bentley Goes After Magnet Materials & Manufacturing Advancements
Magnetism Plays Key Roles in DARPA Research to Develop Brain-Machine Interface without Surgery
Research & Development
Product News
Industry News
Events Calendar/ Advertising Index
Toshiba’s New Magnetic Material Improves Motor Energy Conversion Efficiency
Visions
Magnetics Business & Technology - July/August 2021 - Magnetics Business & Technology - July/August 2021
Magnetics Business & Technology - July/August 2021 - Cover2
Magnetics Business & Technology - July/August 2021 - 3
Magnetics Business & Technology - July/August 2021 - Editor’s Choice/ Features
Magnetics Business & Technology - July/August 2021 - 5
Magnetics Business & Technology - July/August 2021 - Major Automakers Transform Design & Manufacturing Operations on Accelerated Path to e-Propulsion – Part 2 of 2
Magnetics Business & Technology - July/August 2021 - 7
Magnetics Business & Technology - July/August 2021 - 8
Magnetics Business & Technology - July/August 2021 - 9
Magnetics Business & Technology - July/August 2021 - 10
Magnetics Business & Technology - July/August 2021 - 11
Magnetics Business & Technology - July/August 2021 - Luxury Auto Maker Bentley Goes After Magnet Materials & Manufacturing Advancements
Magnetics Business & Technology - July/August 2021 - 13
Magnetics Business & Technology - July/August 2021 - 14
Magnetics Business & Technology - July/August 2021 - 15
Magnetics Business & Technology - July/August 2021 - Research & Development
Magnetics Business & Technology - July/August 2021 - 17
Magnetics Business & Technology - July/August 2021 - 18
Magnetics Business & Technology - July/August 2021 - 19
Magnetics Business & Technology - July/August 2021 - 20
Magnetics Business & Technology - July/August 2021 - 21
Magnetics Business & Technology - July/August 2021 - Product News
Magnetics Business & Technology - July/August 2021 - 23
Magnetics Business & Technology - July/August 2021 - 24
Magnetics Business & Technology - July/August 2021 - 25
Magnetics Business & Technology - July/August 2021 - Industry News
Magnetics Business & Technology - July/August 2021 - 27
Magnetics Business & Technology - July/August 2021 - 28
Magnetics Business & Technology - July/August 2021 - 29
Magnetics Business & Technology - July/August 2021 - 30
Magnetics Business & Technology - July/August 2021 - 31
Magnetics Business & Technology - July/August 2021 - Events Calendar/ Advertising Index
Magnetics Business & Technology - July/August 2021 - 33
Magnetics Business & Technology - July/August 2021 - Visions
Magnetics Business & Technology - July/August 2021 - Cover3
Magnetics Business & Technology - July/August 2021 - Cover4
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