ASNT Level III: Ch. 4 Ultrasonic Testing with Complete Solutions 2023

Ultrasonic waves propagate through test materials in the form of: - ANSWER-mechanical vibrations When an ultrasonic beam passes through the interface of two dissimilar materials at an angle, a new angle of sound travel takes place in a the second material due to : - ANSWER-refraction The gradual loss of energy as ultrasonic vibrations travel through material is referred to as: - ANSWER-attenuation Ultrasonic velocities are different for different materials. These difference are primarily caused by differences in the materials': - ANSWER-elasticity and density Ultrasonic energy for immersion testing is transmitted to the test object as a compressional wave because: - ANSWER-liquids will only sustain compressional waves When inspecting coarse-grained materials, which of the following frequencies will generate a sound wave that will be most easily scattered by the grain structure? - ANSWER-10 MHz In general, shear waves are more sensitive to small discontinuities than longitudinal waves for a given frequency and in a given material because: - ANSWER-the wavelength of shear waves is shorter than the wavelength of longitudinal waves The ability of transducers to detect echoes from small discontinuities is a definition of - ANSWER-sensitivity Which of the following will create a resonance condition in a speciment? - ANSWER-Continuous longitudinal waves The display on most basic pulse-echo ultrasonic instruments consist of: - ANSWER-an A-scan presentation In a basic pulse-echo ultrasonic instrument, the components that produces the voltage that activates the search unit called - ANSWER-a pulser The primary purpose of reference blocks is to: - ANSWER-obtain a common reproducible reference standard The general use of distance-amplitude correction is to compensate for - ANSWER-attenuation, distance, and beam spread In area-amplitude ultrasonic standard test blocks, the flat-bottom holes in the blocks are: - ANSWER-difference diameter, increase n 0.4mm (0 .2in) increments from the No. 1 block to the No. 8 block Which of the following factors has the least influence on the amount of energy reflected from a discontinuity? - ANSWER-Test frequency The presence of a discontinuity will not produce a specific discontinuity indication on the ultrasonic instrument display when which of the following techniques is used? - ANSWER-Through-transmission testing Lack of parallelism between the entry surface and the back surface: - ANSWER-may result in a screen pattern that does not contain back reflection indications Significate errors in ultrasonic thickness measure can occur if: - ANSWER-the velocity of propagation deviates substantially from an assumed constant value for a given material In contact testing, shear waves can be induced in the test material by: - ANSWER-using an angle-beam transducer with the transducer mounted on a plastic wedge so that sound enters part an an angle The most commonly sued method of producing shear waves in a test part when inspecting by the immersion method is by: - ANSWER-angulating the search tube to the proper angle with respect to the entry surface of the test part In immersion testing, proof that the search unit is normal (perpendicular) to a flat entry surface is indicated by: - ANSWER-maximum reflection amplitude from the entry surface In immersion testing, the water distance between the search unit and the test piece: - ANSWER-should be the same as the water distance used during calibration Generally, the best ultrasonic testing technique for detecting discontinuities oriented along the fusion zone in a welded plate is: - ANSWER-an angle-beam method using shear waves