Testing Methods (5)

Question 1

What is Straight-Beam Testing?

Answer 1

The sound wave is transmitted perpendicular to the entry surface

• longitudinal waves
• 90° to entry surface
• Single/Dual Transducer

Question 2

What is Straight-Beam Testing used for?

Answer 2

• Measure material thickness
• Detect corrosion
• Find disbonding
• Find discontinuities that lay in direction parallel to the front surface

Question 3

What is Angle-Beam Testing?

Answer 3

Direct the sound wave at an angle other than 0°

• Shear Waves
• Wedge cut below the FCA for longitudinal waves

Question 4

What is Angle-Beam Testing used for?

Answer 4

• Detection of discontinuities laying at an angle, relative to the front surface

Question 5

What is Surface Wave Testing?

Answer 5

Direction of sound waves parallel to the surface at the surface

Question 6

What is Surface Wave Testing used for?

Answer 6

• Detect surface breaking discontinuities on smooth surfaces inaccessible to other surface testing methods

Question 7

What is Plate Wave Testing used for?

Answer 7

• Inspect thin sheets in the order of one wavelength

Question 8

What is Contact Testing?

Answer 8

The transducer is in contact with the material being inspected with a thin layer of couplant in between
- Shear, Longitudinal, Plate, Surface

Question 9

What is Immersion Testing?

Answer 9

The transducer is positioned with some distance from the test material, and water acts as the couplant
- Longitudinal, Shear

Question 10

What is Pulse Echo Testing?

Answer 10

The crystal is electrically energized for a pulse and waits for an echo. The echo is shown on the UT screen and can be analyzed for information about the defects found

Question 11

Advantages of Pulse Echo Testing

Answer 11

• Only require access to one side of the surface
• One probe required
• Accurate location of defects is possible
• Can see the same defect more than once

Question 12

Disadvantages of Pulse Echo Testing

Answer 12

• More attenuation (from more sound travel)

- single element transducers can; have poor near surface resolution, difficult to test thin materials, near field

Question 13

What is Continuous Testing?

Answer 13

The transducer is continuously energized rather than pulsed

• Through-Transmission
• Resonance

Question 14

What is Through-Transmission Testing?

Answer 14

Two transducers on opposing sides of a material (one transmits sound, other receives). Can use pulse-echo or continuous testing.

Question 15

What is Through-Transmission Testing used for?

Answer 15

Finding Material thickness (in terms of energy transmitted or lost)
- Echo reflectors are not displayed on screen

Question 16

Advantages of Through-Transmission Testing

Answer 16

• fast automated scanning
• no dead zone
• no near field effects
• less attenuation

Question 17

Disadvantages of Through-Transmission Testing

Answer 17

• need access to both sides of the surface
• probe alignment is critical
• manual testing is awkward
• depth of reflectors not given
• can’t distinguish multiple reflectors

Question 18

What is Pitch and Catch Testing?

Answer 18

Two transducers, used on same, opposite or adjacent surfaces. Uses straight beam, angle beam or combo

Question 19

What is Pitch and Catch Testing used for?

Answer 19

• Measures material thickness

- Detect angled discontinuities

Question 20

Advantages of Pitch and Catch Testing

Answer 20

• good near surface resolution
• no near field effects
• one surface access minimum
• detect angled discontinuities
• large discontinuities can be sized

Question 21

Disadvantages of Pitch and Catch Testing

Answer 21

• Two transducers
• if an angle beam, refracted angle must be controlled
• manual testing is awkward
• alignment is critical

Question 22

What is Resonance Testing?

Answer 22

Continuous longitudinal wave with a varying frequency

Question 23

What is Resonance Testing used for?

Answer 23

• To measure specimen thickness