Ultrasonic Questions 2.pdf

7/25/2019 Ultrasonic Questions 2.pdf

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From most of the active surface

From a small area in the center of the active surface

From the edges of the active surface

18

The active element of most acoustic transducers used today is:

Lithium

Piezoelectric ceramic

Sulfide

Quartz

19

The act of evaluating and adjusting the precision and accuracy of themeasurement equipment is called:

Standardization

Calibration

Accuracy Tuning

20

The ability to locate a small discontinuity is called:

Resolution

Sensitivity

Wavelength

Frequency

21 What is used to support the active element and dampen thetransducers characteristics?

Resin

Oil Backing material with a similar the impedance of the transducer Any of the above will work

22

In angle-beam testing, when the geometry of the part is relativelyuncomplicated and the orientation of a flaw is well known, the length

of a crack can be determined by a technique known as:

Tip diffraction

Immersion

Surface mode diffraction

Contact testing

23

The first critical angle describes the condition where the:

Página 4 de 7Ultrasound Quiz 1

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The angle of the refracted longitudinal wave is less than 90o

The angle of the refracted longitudinal wave is exactly 90o

The angle of the refracted longitudinal wave is greater than 90o

The angle of the refracted shear wave is exactly 90o

24

In order to have a reasonable chance at detecting a discontinuity, thereflective surface of the discontinuity must have a dimension that is atleast as long as ________ wavelength.

One-half One

Two

0ne-quarter

25

Some transducers are specifically fabricated to be:

Better transmitters

Better receivers

Used in high temperature applications

All of the above

26

The sound energy or ultrasonic beam is more uniform in the:

Far field zone

Near field zone

Interface between the transducer and plastic wedge

Band along the central axis

27

Which type of test block is used to check horizontal linearity and thedB accuracy per requirements of AWS and AASHTO?

Distance/Sensitivity block A DSC block A rompus block A shear wave calibration block

28

DACC stands for:

Distance Amplitude Correction Curve

Direct Application Correction Curve

Distance Area Correction Calculation

Distance Area Computer Controlled

When a single element transducer is operating in the pulse echo





29 mode, the element:

Can not start receiving reflected signals until the element has stoppedringing from its transmit function

Needs to have a high pulse rate

Should be used in the dual mode

Can only be made with lithium sulfate

30

When a longitudinal wave encounters an interface between twomaterial with different accoustic impedances, what occurs when theangle of incidence is 90 degrees?

Reflection

Refraction

Mode conversion

Reflection and refraction

31

What is the correct formula for calculating the wavelength when thewave velocity and frequency are known?

None of the above

32

The material of the reference standard used to setup for a flawinspection:

Can be made from similar material as long as the velocity is the same

Should be the same material being inspected Must have the same impedance values as the base material Can only be used once

33

A decibel is:

A unit of measure used only for sound measurements

A logarithmic unit that describes a ratio of two measurements

A logarithmic unit that describes the product of two measurements

None of the above

34

What type of transducer contains two independently operatingelements in a single housing?





Crystal mosaic transducer Dual element transducer Liquid crystal transducer Bi polar transducer

35

Mode conversion, occurs when a sound wave encounters an interfacebetween materials of different acoustic impedance and:

One of the two materials is a liquid The incident angle is greater than the first critical angleThe incident angle is greater than the second critical angle

The incident angle is not normal to the interface

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