Layers of lead foil, used in intimate contact with the film during exposure. they act to improve radiographic quality or to decrease exposure time, or both.
Sweep length (ut), английский Length of time or distance represented by the horizontal base line on an a-scan.
Reciprocity law (rt), английский Law that states that the film blackening is determined by the product of the milliamperage or source strength and the time of exposure. see reciprocity law failure.
