testing that has applications in medical imaging and industrial
nondestructive testing, originally pioneered by Albert Macovski of
Stanford University.[1] In medicine a common application of phased
array is the imaging of the heart (images of the fetus in the womb are
usually made by curvilinear array, a multi-element probe that does not
actually phase the signals). When applied to metals the PA image shows
a slice that may reveal defects hidden inside a structure or weld.
Principle of operation
The PA probe consists of many small ultrasonic elements, each of which
can be pulsed individually. By varying the timing, for instance by
pulsing the elements one by one in sequence along a row, a pattern of
constructive interference is set up that results in a beam at a set
angle. In other words, the beam can be steered electronically. The
beam is swept like a search-light through the tissue or object being
examined, and the data from multiple beams are put together to make a
visual image showing a slice through the object.
Features of phased array
The method most commonly used for medical ultrasonography.
Multiple probe elements produce a steerable, tightly focused, high-
resolution beam.
Produces an image that shows a slice through the object.
Compared to conventional, single-element ultrasonic inspection
systems, PA instruments and probes are more complex and expensive.
In industry, PA technicians require more experience and training than
conventional technicians.
Standards:
European Committee for Standardization (CEN)
prEN 16018, Non destructive testing - Terminology - Terms used in
ultrasonic testing with phased arrays
Principle of operation of phased array (PA). The PA probe consists of
many small elements, each of which can be pulsed separately. In the
figure the element on the right is pulsed first, and emits a pressure
wave that spreads out like a ripple on a pond (largest semicircle).
The second to right element is pulsed next, and emits a ripple that is
slightly smaller than the first because it was started later. The
process continues down the line until all the elements have been
pulsed. The multiple waves add up to one single wave front travelling
at a set angle. In other words, the beam angle can be set just by
programming the pulse timings.
Regards,
Suresh Babu,
QA/QC Inspector,
KSA.
On Dec 8, 3:10 pm, yusufkhan pathan <yusufkhan...@gmail.com> wrote:
> Dear all,
>
> Please provide some information related to phased array technique.
>
> Thanks in advance
>
> Regards.
> Yusufkhan.Pathan
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