A predefined limit or level used in non-destructive testing to determine the presence or absence of a signal or indication. It serves as a reference point for distinguishing between acceptable and unacceptable conditions during inspection.

A non-destructive testing technique that involves the use of two separate transducers or probes arranged in tandem, with one transmitting and the other receiving.

The depth to which the eddy current density has decreased to 1/e or 36.8% of the surface density.

The velocity at which sound or ultrasonic waves travel through a medium, such as a solid, liquid, or gas.

A fundamental principle in physics that describes the relationship between the angles of incidence and refraction when a wave passes through an interface or boundary between two different media.

The process of creating a virtual or computer-based model or representation of a non-destructive testing scenario or system to simulate and analyze wave propagation, interactions, or inspection results for testing optimization or training purposes.

A measure of the relative strength or magnitude of a desired signal compared to the level of background noise or unwanted signals, used to assess the quality and clarity of inspection results.

A type of ultrasonic wave that propagates perpendicular to the direction of wave motion, producing particle motion parallel to the test surface.

The process of confirming or ensuring the adequacy and accuracy of the sensitivity settings or capabilities of a non-destructive testing system or method through the use of calibration standards, reference blocks, or test objects.

The ability of a non-destructive testing method or system to detect and measure small flaws or changes in a material.