POWER December 2015 - 20

critical variables, as well as on the device
itself. This advanced diagnostic capability
allows for the creation of custom alarm
schemes and system status notifications.
All diagnostic status messages are displayed
in accordance with NAMUR (the
German-based user association of automation
technology in process industries)
directive NE107 so that operators can recognize
events and initiate appropriate action,
if required.
The transmitter includes an event log
that records all calibration and alarm
events. Each event is date and time
stamped, enabling the operator or maintenance
technician to quickly access the
history. The user interface is simple and
shares the same look and feel as ABB's
other instruments and analyzers. A sixbutton
tactile keypad for menu navigation
and data input, combined with an
intuitive menu structure, enables users to
quickly and easily access, program, and
adjust settings and operational data from
one screen.
-Clive Henderson is global product manager
gas analysis for ABB's Measurement
and Analytics business unit.
An " Acoustic Mouse " for
Handheld 3-D Imaging
Ultrasonic testing (UT) has long been a
key method for detecting defects and service-induced
degradation in nuclear and
fossil plant components and for supporting
remaining component life assessment.
But it comes with some tradeoffs.
Manual scanning with handheld transducers
allows quick and easy testing of
large areas at low cost, but the results
are mostly qualitative and can be plagued
with false positives. This requires a conservative
approach, which means shorter
inspection intervals and sometimes-unnecessary
repairs and replacements.
Automated UT using mechanized scanners
can produce highly accurate threedimensional
(3-D) scans of component
interiors, which can be stored, reconstructed,
and manipulated, enabling
quantitative flaw analysis and better decision-making.
These inspection systems,
however, are expensive, cumbersome,
time-consuming and difficult to operate,
and cannot always reach critical areas in
an operating plant.
The ideal UT system would be small
and handheld, yet capable of high-resolution
3-D scanning. A research project
led by the Electric Power Research Institute
(EPRI) is developing just such a
tool, which it refers to as an " acoustic
mouse " (Figure 3).
20
3. Small but powerful. This prototype handheld 3-D ultrasonic testing transducer is under
development by the Electric Power Research Institute (EPRI). Courtesy: EPRI
4. Real-time 3-D. EPRI's " acoustic mouse " has proven capable of generating high-quality
3-D scans in testing. Courtesy: EPRI
Technological Challenges
The challenges for a handheld 3-D UT
system are twofold: precise tracking of
the transducer position-necessary for
3-D imaging-and a portable transducer
design that allows high-resolution image
capture at a reasonable level of data
processing. These functions, according
to EPRI, also needed to be integrated
" within a hardware and software system
supporting seamless operation of
manual scanning, position-tracking, 3-D
imaging, computer encoding, data visualization
and analysis, and condition assessment
technologies. "
EPRI began work on the project in 2009,
recognizing that advances in ultrasonic
scanning developed for medical and geophysical
applications held promise for UT
of power plant components. Developmental
work has focused on improving signal
processing, pattern recognition, and other
methods to support accurate position
tracking and data reconstruction.
Previous UT scanners required highchannel
transducers for 3-D image reconstruction,
while large ultrasonic apertures
www.powermag.com
are necessary to achieve depth focusing
throughout the interior of thick-section
components. The EPRI project has developed
new linear and matrix sparse-array
configurations with the potential to
achieve the same results as larger scanners
using a smaller number of array elements
and a smaller number of channels.
Small, Handheld, Powerful
Tests of the prototype developed by EPRI,
showed it was capable of generating highquality
real-time computer-encoded images
of simulated defects and internal
features in reference blocks and component
mockups (Figure 4).
Though the EPRI acoustic mouse is not
yet being manufactured, EPRI is currently
working with instrument manufacturers
and plant owners to develop commercial
models and support code qualification
for the instruments, as well as develop
training programs for their use. The first
models are expected to be commercially
available in 2016. ■
-Thomas W. Overton, JD is a POWER
associate editor.
POWER | December 2015
http://www.powermag.com
POWER December 2015

Table of Contents for the Digital Edition of POWER December 2015
