The Rosetta Stone

Phased Array reuses the same ultrasound terminology, but also brings a couple of new expressions.  Here is supplied a short-form reference to make sure we understand each other.

 

NDT

Nondestructive Testing.  Also refered as Nondestructive Evaluation (NDE).


Phased Array Ultrasound Technique (PAUT)

An ultrasound technique that uses an array of miniature transducers to generate ultrasound beams.  Each array element is electronically controlled so that many beams can be generated by a single array transducers.


Beam

The acoustic pressure field that is generated by a transducer.


Beamformer

The electronic module that controls the array elements to generate beams.  Typically, the beamformer controls delays, apodization and sum.  The beamformer performs beamforming.


Linear Array (1D)

An array with many elements in one row.


Matrix Array (2D)

An array with elements organized in rows and columns.


Detachable Active Array Head (DAAH)

The piezoelectric portion of a phased array probe that can be disconnected from the probe frame.


L-scan

The Linear Scan is the view generated when the beams generated are from different activated array elements, at a constant transmitted angle.  The index point moves linearly and the L-scan view will appear as a parallelogram at the beam angle.  Sometimes refered as E-scan.


S-scan

The Sector Scan is the view generated when the beams are swept from a low to high angle.  It’s the common pie-shaped image of obstetrics.


C-scan

View produced from gated A-scans collected at different positions, but at the same angle.  Can be a Position C-scan or an Amplitude C-scan, depending on the type of gating.


Multi-Scan

The amalgamate of several S-scans or L-scans on the screen.  Each scan has its own settings.


Focal Law

The set of all parameters to generate a beam using the beamformer features (i.e. delay, apodization, sum, etc.).  A focal law lists all parameters for each channel.


Delay Law

The portion of a focal law that is about time delays.


ACG

Angle-Corrected Gain.  The use of different gains for different focal laws.  ACG is typically used for S-scans, where higher angles require higher gain.


TCG

Time-Corrected Gain.  Also known as TGC for Time-Gain Compensation, a term widely used in analog amplification.


DAC Curve

Distance-Amplitude Correction Curve.  A curve drawn on screen that shows the amplitude decay in the material due to its attenuation.  Each flaw echo can be compared to the DAC curve to call its nocivity,


PRF

Pulse Repetition Frequency.  The number of firings of ultrasound per second.


Encoders

Device used to encode the search unit exact location on the component to inspect.


Angular Echodynamic

The fade-in / fade-out shape of an indication spot in a S-scan view, as a function of angle.


Lateral Echodynamic

The fade-in / fade-out shape of an indication spot in a L-scan (or B-scan), as a function of index point (or position).  Also refered as Echodynamic.

Tel:   +1 418  683-6222 

Fax:  +1 418  683-7032

Toll Free:  +1 866  HARFANG    

e-mail:  info@harfangmicro.com