2 Radiography - X And Gamma
2.1 Introduction to Radiography
This technique is suitable for the detection of internal defects in ferrous and nonferrous
metals and other materials.
X-rays, generated electrically, and Gamma rays emitted from radio-active isotopes,
are penetrating radiation which is differentially absorbed by the material through
which it passes; the greater the thickness, the greater the absorbtion. Furthermore,
the denser the material the greater the absorbtion.