L32 STRAIGHT BEAM AND ANGLE BEAM

1. M.KARTHIKEYAN
ASSISTANT PROFESSOR
DEPARTMENT OF MECHANICAL ENGINEERING
AAA COLLEGE OF ENGINEERING & TECHNOLOGY, SIVAKASI
karthikeyan@aaacet.ac.in
ME8097 NON DESTRUCTIVE
TESTING AND EVALUATION

2. UNIT IV ULTRASONIC TESTING (UT) AND ACOUSTIC
EMISSION (AE)
1. Ultrasonic Testing-Principle,
2. Transducers,
3. Transmission and pulse-echo method,
4. Straight beam and angle beam,
5. Instrumentation,
6. Data representation, A/Scan, B-scan, C-scan.
7. Phased Array Ultrasound, Time of Flight Diffraction.
8. Acoustic Emission Technique – Principle,
9. AE parameters, Applications

3. INSPECTION METHODS
1. PULSE ECHO METHOD
2. THROUGH TRANSMISSION METHOD
3. ANGLE BEAM ULTRASONIC TESTING
4. IMMERSION ULTRASONIC TESTING

4. ANGLE BEAM ULTRASONIC TESTING

5.  Straight beam techniques can be highly effective at finding
laminar flaws, they are not effective when testing many
common welds, where discontinuities are typically not oriented
parallel to the surface of the part.
 The combination of weld geometry, the orientation of flaws, and
the presence of the weld crown or bead require inspection from
the side of the weld using a beam generated at an angle.
 Angle beam testing is by far the most commonly used technique
in ultrasonic flaw detection.

6. ANGLE BEAM ULTRASONIC TESTING

7. IMMERSION ULTRASONIC TESTING
 Another way to couple the sound from transducer to a test object is
coupling the sound with water.
 This can be done by immersing the transducer and test object in a tank
of water.
 In immersion testing, the transducer is placed in the water, above the
test object, and a beam of sound is projected.
 The graph of peaks using the immersion method is slightly different.
 Between the initial pulse and the back wall peaks there will be an
additional peak caused by the sound wave going from the water to the
test material.
 This additional peak is called the front wall peak.

9.  The ultrasonic tester can be adjusted to ignore the initial pulse
peak, so the first peak it will show is the front wall peak.
 Some energy is lost when the waves hit the test material, so the
front wall peak is slightly lower than the peak of the initial
pulse.
 Ultrasonic testing is an NDT test technique that interrogates
components and structures to detect internal and surface
breaking defects, and measures wall thickness on hard (typically
metallic or ceramic) components and structures

10. Moving a search unit over a test surface either manually or
automatically is referred to as:
(a) Scanning
(b) Attenuating
(c) Angulating
(d) Resonating
MCQ - 1

11. In an A scan presentation, the horizontal base line
represents the:
(a) Amount of refracted ultrasonic sound energy
(b) Distance traveled by the search unit
(c) Elapsed time or distance
(d) None of the above
MCQ - 2

12. An ultrasonic testing technique in which the transducer
element is not parallel to the test surface is called:
(a) Angle beam testing
(b) Immersion testing
(c) Contact testing
(d) Through-transmission testing
MCQ - 3

13. A test method employing two seperate search units on
opposite surfaces of the material being tested is called:
(a) Contact testing
(b) Surface wave testing
(c) Through-transmission testing
(d) Lamb wave testing
MCQ - 4

14. Which of the following is not (!) a requirement of a
couplant?
(a) Easy application
(b) Highly penetrating
(c) Harmless both to the test piece and transducers
(d) Excludes all air between transducer and test piece
MCQ - 5