The active element of most acoustic transducers used today is:
Lithium Piezoelectric ceramic Sulfide Quartz The measure of how a signal from a defect compared to other background reflections is called:
Acoustic impedance Signal to noise ratio Refraction Reflection
Which type of calibration block closely resembles the miniature anglebeam block and is used in a similar way?
An IIW block A DSC block A rompus block A shear wave calibration block
In the transverse or shear wave, the particles:
Move in an elliptical pattern Oscillate at a right angle to the direction of wave propagation Oscillate parallel to the direction of wave propagation Do not actually move Within a given material, the speed of sound:
Is constant Decreases with distance from the transducer Increases with distance from the transducer
None of the above
The sound that emanates from a piezoelectric transducer originates:
From a point on the active surface From most of the active surface From a small area in the center of the active surface From the edges of the active surface The ability to locate discontinuities that are close together within the material is called:
Resolution Sensitivity Effectiveness Phase delay
Which of the following would make a good couplant?
Water Oil Glycerin All of the above The number of cylces per second is the definition of:
Wave speed Frequency Hertz None of the above Acoustic impedance is identified by the letter:
Z I V P When a longitudinal wave encounters an interface between two material with different accoustic impedances, what occurs when the angle of incidence is 90 degrees?
Refraction Mode conversion Reflection and refraction
Contact transducers often incorporate a:
Composite frequency adjustment Vibration suppressor Wear plate Phase adjustment sensor Which type of screen presentation displays the amount of received ultrasonic energy as a function of time?
A-scan B-scan C-scan All of the above
What part of the ultrasonic machine generates short, large-amplitude pulses of controlled energy?
Pulser Amplifier Transducer Scanner
When a wave encounters an interface at an oblique angle, what takes place at the interface due to the different sound velocities of the two materials?
Attenuation Refraction Beam spread Beam impedance
The a large acoustic impedance mismatch at an interface will result in:
A high amount of transmitted sound energy A small degree of refraction A large critical angle A high amount of reflected sound energy
Which type of transducer can be used to scan wide areas when high sensitivity is not required?
Mosaic transducer Single crystal transducer of small diameter Composite transducer Paint brush transducer
What is the material called that is used to improve the transmission of ultrasonic sound energy from the transducer into the part?
Gel Goo Couplant Contact paste
The act of evaluating and adjusting the precision and accuracy of the measurement equipment is called:
Standardization Calibration Accuracy Tuning
When a single element transducer is operating in the pulse echo mode, the element:
Can not start receiving reflected signals until the element has stopped ringing 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
C opyright � T he C ollaboration for NDT Educ ation..