FREE NDT Ultrasonic Testing Questions and Answers
The reflective surface of the discontinuity must have a diameter at least as long as ________ wavelength in order to provide a fair chance of being detected.
The reflective surface of a discontinuity must have a diameter at least as long as one-half wavelength to provide a fair chance of being detected. This criterion is based on principles of ultrasonic testing, where the wavelength of the sound wave is crucial for detecting and characterizing defects or discontinuities within a material. Having a reflective surface with a diameter of at least one-half wavelength helps ensure that the discontinuity reflects a sufficient portion of the ultrasonic wave back to the transducer for detection.
In general, resolution rises:
In general, resolution increases with an increase in transducer frequency. Higher-frequency ultrasound waves have shorter wavelengths, allowing them to detect smaller defects or features within a material. Therefore, higher-frequency transducers are capable of providing higher resolution images and better detection of fine details compared to lower-frequency transducers.
Which kind of calibration block is utilized similarly to the small angle-beam block and looks a lot like it?
This type of calibration block is similar in function to the small angle-beam block and often resembles it in appearance. The DSC block is used for calibrating ultrasonic testing equipment to ensure accurate measurement of distances and amplitudes of reflected signals.
The term for the combined impact of absorption and dispersion is:
Attenuation refers to the combined impact of absorption and dispersion, which reduce the intensity or magnitude of a signal as it travels through a medium. In ultrasonic testing, attenuation is an important consideration as it affects the ability to detect and characterize flaws or discontinuities within a material.
DAC represents:
In a specific substance, the sound speed is:
In a specific substance, the speed of sound generally remains constant, assuming the substance's properties remain uniform throughout. This means that the speed of sound doesn't change with distance from the transducer or any other factor within the substance itself. However, it's worth noting that the speed of sound can vary depending on the medium through which it travels, such as air, water, or solids, due to differences in density, elasticity, and other factors.
At a depth of roughly: Surface waves, also known as Rayleigh waves, travel along the surface of relatively thick solid materials.
Surface waves, also known as Rayleigh waves, travel along the surface of relatively thick solid materials. At a depth of approximately one wavelength below the surface, the energy of Rayleigh waves is mostly concentrated. This depth corresponds to roughly one wavelength of the Rayleigh wave.
In the pulse echo mode, a single element transducer functions as follows:
In the pulse-echo mode, a single-element transducer typically operates by transmitting a pulse of ultrasound and then switching to receive mode after the element has stopped ringing from its transmit function. This ensures that the transducer is not actively transmitting while trying to receive reflected signals, which could lead to interference or distortion in the received signal.
The following is the measurement of a defect's signal in relation to other background reflections:
The measurement of a defect's signal in relation to other background reflections is typically referred to as the signal-to-noise ratio (SNR). The SNR represents the ratio of the amplitude of the signal (defect) to the amplitude of background noise, providing a measure of the quality of the signal relative to the noise level.
The capacity to identify a tiny discontinuity is known as:
The capacity to identify a tiny discontinuity is referred to as sensitivity in non-destructive testing (NDT). Sensitivity measures the ability of the testing method to detect small defects or variations in a material. In ultrasonic testing, for example, sensitivity relates to the ability to detect and accurately characterize discontinuities of various sizes.
Other names for longitudinal waves are:
Longitudinal waves are also known as compressional waves or pressure waves. These terms all refer to the same type of wave where the oscillations of the medium are in the same direction as the direction of wave propagation.