اصطلاحات کاربردی در UT

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جهت تکمیل اصطلاحات و کمک به ترجمه اصطلاحات به لینک زیر مراجعه فرمایید
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http://parsweld.com/forum/index.php?page=topic&show=1&id=5

amplitude:

The vertical height of a received signal on an A-scan, measured from base to peak for an A-scan (rectified) presentation or from peak to peak for an RF presentation.


angle beam :
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An ultrasound beam travelling at an acute angle into a medium. The angle of entry angle of refraction is measured from the source to the entry surface.
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angle beam probe

Alternative: angle beam transducer ,

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A contact probe by means of which ultrasonic waves can be transmitted from or received into a test object so that the beam angle impacts at an angle other than 90 degrees (right angle) to the surface of workpiece. Special for contact testing are techniques applied using a variable adjustment of incidence (buffers).
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angle beam probe

Alternative: angle beam transducer ,

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A contact probe by means of which ultrasonic waves can be transmitted from or received into a test object so that the beam angle impacts at an angle other than 90 degrees (right angle) to the surface of workpiece. Special for contact testing are techniques applied using a variable adjustment of incidence (buffers).

Angle Corrected Gain:​

Also called ACG. This is compensation for the variation in signal amplitudes received from a constant soundpath during S-scan calibration. The compensation is typically performed electronically at multiple depths. Note that there are technical limits to ACG, i.e. beyond a certain angular range, compensation is not possible.
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beam spread

Alternative: angle of beam divergence ,

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The divergence of the sound beam as it travels through a medium. Specifically, the solid angle which contains the main lobe of the beam in the far field.

angle of impingement :​

The included angle between the beam axis of the incident wave and the angle to the surface at the point of impingement on the reflector.

angle of incidence :​

The included angle between the beam axis of the incident wave and the angle to the surface at the point of incidence.


angle of reflection :​

The included angle between the beam axis of the reflected wave and the angle to the reflection surface at the point of reflection.

angle of refraction :​

The angle between the bearn axis of a refracted wave and the angle to the refracting interface. The refraction when passing through the interface changes the direction of propagation of the sound wave according to Snell's reflection law.

angle of squint :​

The angle by which the ultrasonic beam axis deviates from the probe axis. Manufacturers try to guarantee a value of less then 2°. Offset should be less than 1 mm from the center point of the probe. These tolerances make precisely adjustable holders necessary. Precise alignment of the transducer to a point of incidence is essential to the test result. Thus the part is guided to remain in the desired position, or the transducer is mounted in a cardan joint fixture and guided via a prism on the part surface.

angle testing :​

A method of ultrasonic testing in which transmission of ultrasound is at an acute angle to the entry surface. Usually called angle beam testing. This may be done to achieve special effects such as setting up transverse or surface waves by mode conversion at an interface. Most angle beam testing, however, utilizes the transverse wave only. This requires the incident angle to be greater than the first critical angle. Basicly the angle testing is done to achieve detection of defects. These are only detectable under a certain angle incidence. Techniques that are applied using a variable adjustment of incidence (buffers) are specifically for contact testing.

anisotropy :​

A condition in which properties of a medium (velocity, absorption, for example) depend on direction in the medium. Testing of anisotropic materials, e.g., austenitic steel, presents a challenge for ultrasonics.

annular array probes:​

Phased array probes that have the transducers configured as a set of concentric rings. Annular array probes allow the beam to be focused to different depths along an axis. The surface area of the rings is in most cases constant, which implies a different width for each ring.​

antinode:​

A point in a standing wave where certain characteristics of the wave field have maximum amplitude.

phased array transducer:​

A transducer made up of several piezo- electric elements individually connected so that the signals they transmit or receive may be treated separately or combined as desired. Multiple piezoelectric elements are sometimes arranged in patterns in a commom housing, these are usually linear, matrix or annular in shape. The elements can be pulsed simultaneous ( as with "paintbrush" probes), or the elements are pulsed in a certain pattern to each other. With the last, some sophisticated methods are applied, e.g., angle of incidence controllable by electronics, phased array focusing (beam steering, dynamic focusing). UT needs often several transducers for the detailed inspection of a part. In order to reduce the duration of such a test, electronically driven array transducers generating ultrasounds propagating in various directions are more and more often used. The inspected sample can thus be quickly scanned. The following animations are part of the Imasonic Homepage.​

Resonant Inspection:
Abbreviation: RI, ART,​

A whole body inspection. Originally it was used to sort good parts from 'clunkers' by hitting them and listening to them ring.Today instrumentation is available to interpret the resonance spectrum. The classical inspection determines the vibration behaviour of a test object via a Fourier analysis of the received signals. This is of disadvantage because computing time is consumed for the signal transformation, because a very broadband spectrum is excited which is mostly not required for assessing the test object at all, and because ambient noise often interferes with the signal evaluation.​

In 1992, Los Almos National Laboratory developed a resonance test system that can do without the Fourier analysis. This resonance method can be applied to testing of all oscillatory objects made of ceramics and glass, of forged and cast metals and of sintered metals. Even jointed ceramic and metal parts, e.g. laser-welded parts, which can otherwise hardly be tested, can be analyzed by this method.

ASME holes :
Cross-drilled holes with diameter and position as required by the ASME* pressure vessel code.
* American Society of Mechanical Engineers

attenuation coefficient :
A factor which is determined by the degree of determination in sound wave energy per unit of distance traveled. It is composed of two parts, one (absorption) proportional to frequency, the other (scattering) dependent on the ratio of grain or particle size to wavelength. Attenuation of metals have mostly up to 10 dB/m, plastics up to 100dB/m and rubber or wood over 100dB/m. Since the attenuation is frequency dependent, a single attenuation coefficient only applies to a single frequency.

attenuator :​

A device for causing or measuring attenuation, usually calibrated in decibels.
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