FREE ASNT Ultrasonic Questions and Answers
The piezoelectric material in a transducer that vibrates to produce ultrasonic waves is called a:
Explanation:
The piezoelectric material in a transducer that vibrates to produce ultrasonic waves is called a "Crystal." Piezoelectric crystals convert electrical energy into mechanical vibrations and vice versa when subjected to an electric field, making them essential components of ultrasonic transducers.
In immersion testing, the position of the transducer is often varied to transmit sound into the test part at various angles to the front surface. Such a procedure is referred to as:
Explanation:
In immersion testing, varying the position of the transducer to transmit sound into the test part at various angles to the front surface is referred to as "Angulation." This technique allows for the examination of different areas of the test part and enhances defect detection by optimizing the sound beam's interaction with the material.
The cable that connects the ultrasonic instrument to the transducer is specially designed so that one conductor is centered inside another. The technical name for such a cable is:
Explanation:
The technical name for the cable that connects the ultrasonic instrument to the transducer, where one conductor is centered inside another, is "Coaxial cable." This design helps minimize interference and signal loss during the transmission of ultrasonic signals between the instrument and the transducer.
The transducer that contains the thinnest piezoelectric crystal is a:
Explanation:
The frequency of an ultrasonic transducer is inversely proportional to the thickness of the piezoelectric crystal it contains. Therefore, a 25 MHz transducer would typically contain the thinnest piezoelectric crystal among the options provided. Higher frequency transducers, such as 25 MHz, have thinner crystals compared to lower frequency transducers like 1 MHz.
The amount of beam divergence from a crystal is primarily dependent on the:
Explanation:
The amount of beam divergence from a crystal is primarily dependent on the frequency and size of the crystal. Higher-frequency crystals and smaller crystal sizes tend to produce narrower beam divergence, while lower-frequency crystals and larger crystal sizes result in broader beam divergence.
The process of comparing an instrument or device with a standard is called:
Explanation:
The process of comparing an instrument or device with a standard to determine its accuracy and adjust it if necessary is called "Calibration." Calibration ensures that the instrument or device provides accurate and reliable measurements or readings.
Another name for a compressional wave is:
Explanation:
Another name for a compressional wave is a "Longitudinal wave." In longitudinal waves, the particle motion is parallel to the direction of wave propagation, causing compression and rarefaction of the medium. This type of wave is commonly used in ultrasonic testing and other nondestructive testing methods.
A material used between the face of a transducer and the test surface to permit or improve the transmission of ultrasonic vibrations from the transducer to the material being tested is called:
Explanation:
A material used between the face of a transducer and the test surface to permit or improve the transmission of ultrasonic vibrations from the transducer to the material being tested is called a "couplant." Couplants are typically gel-like substances, oils, or greases that help to ensure the efficient transfer of ultrasonic energy between the transducer and the test piece, enhancing the accuracy of ultrasonic inspections.
The indication on the instrument display that represents the far boundary of the material being tested is called:
Explanation:
In nondestructive testing (NDT), particularly in methods like ultrasonic testing, the indication on the instrument display that represents the far boundary of the material being tested is referred to as "The back surface reflection." This indication occurs due to the reflection of sound waves from the far surface of the material being tested. It is crucial in determining the thickness or integrity of the material being inspected.
Another name for Rayleigh wave is:
Explanation:
Another name for Rayleigh wave is "Surface waves." Rayleigh waves are a type of surface wave that travel along the surface of a material with an elliptical motion, causing both longitudinal and transverse particle motion. They are commonly encountered in ultrasonic testing and other nondestructive testing methods, particularly when inspecting the surface or near-surface regions of materials.
A 25 MHz transducer would most likely be used during:
Explanation:
Higher frequency transducers, such as a 25 MHz transducer, are typically used in immersion testing. Immersion testing involves submerging the transducer and the test object in a liquid coupling medium, allowing for efficient transmission of high-frequency sound waves into the material. This method is commonly used for inspecting thin materials or detecting fine surface and subsurface defects.