Iridium 192 is typically used for radiography of steel in which thickness range?

Iridium-192 is commonly utilized in industrial radiography for inspecting metallic materials, including steel, due to its suitable radiation characteristics. In the context of thickness, Iridium-192 is effective for penetrating steel sections within the 2" to 3" range, making option C the correct choice.

This range allows for adequate radiographic inspection while maintaining sufficient contrast and image quality. The isotope's energy levels permit it to pass through the typical thickness of steel found in many applications, enabling inspectors to identify internal flaws, weld quality, and overall material integrity.

Other options showcase thickness ranges that exceed the effective capabilities of Iridium-192 in terms of providing clear and interpretable radiographs. For instance, thicker sections may require higher energy sources to penetrate effectively, while thinner sections could use different isotopes or techniques that are more appropriate for their thickness. Hence, focusing on the specified thickness of 2" to 3" accurately highlights the optimal application of Iridium-192 in radiographic testing of steel.