The opposition or resistance to the flow of waves or electrical currents through a medium, influenced by the material’s density, acoustic velocity, and other factors.

A non-destructive testing technique where the test object is submerged or immersed in a coupling medium, typically water, to enhance the transmission and reception of ultrasonic waves.

In ultrasonic testing, a term used to describe the noise or random signals displayed on the screen that do not represent valid indications or flaws, often caused by surface roughness, scattering, or reverberations.

An undesired or false reflection in ultrasonic testing caused by multiple reflections, interfering signals, or reverberations, resulting in misleading or inaccurate indications.

A time or amplitude window set to isolate and analyze specific portions of the signal, allowing for accurate evaluation of reflections from desired depths or locations.

The adjustment of the amplification or sensitivity level of a non-destructive testing system to enhance or attenuate the received signals for optimal flaw detection or measurement.

The number of cycles or oscillations per unit of time, commonly used to describe the characteristics of waves, signals, or electromagnetic radiation in non-destructive.

A set of parameters used in phased array ultrasonic testing to define the time delays and amplitudes of individual elements, controlling the shape and direction of the ultrasonic beam.

An imperfection, defect, or discontinuity in a material or component that can affect its performance, strength, integrity, or serviceability, often targeted for detection or evaluation.

A reference flaw or calibration standard used in ultrasonic testing, featuring a machined hole with a flat bottom surface that can be used to evaluate resolution and flaw sizing capabilities.