What is the maximum allowed density variance across a constant thickness?

What is the maximum allowed density variance across a constant thickness?

• A. Maximum allowed variance is 0.5
• B. Maximum allowed variance is 1.0
• C. Maximum allowed variance is 0.2
• D. Maximum allowed variance is 1.5

Answer: (A)

Density variance across a constant thickness is a measure of how uniform the radiographic image is in the section being examined. If the density changes too much from one area to another across the same thickness, it becomes difficult to distinguish real flaws from natural exposure or geometry effects. The accepted tolerance in this context is 0.5 density units, which provides a practical balance: small, unavoidable variations from setup or scatter are allowed, while still keeping the radiographs reliable for defect detection. Values like 1.0 or 1.5 would let too much nonuniformity pass, potentially masking issues or creating false indications, and 0.2 would be overly restrictive given typical production variations. So the maximum allowed density variance across a constant thickness is 0.5.

Density variance across a constant thickness is a measure of how uniform the radiographic image is in the section being examined. If the density changes too much from one area to another across the same thickness, it becomes difficult to distinguish real flaws from natural exposure or geometry effects. The accepted tolerance in this context is 0.5 density units, which provides a practical balance: small, unavoidable variations from setup or scatter are allowed, while still keeping the radiographs reliable for defect detection. Values like 1.0 or 1.5 would let too much nonuniformity pass, potentially masking issues or creating false indications, and 0.2 would be overly restrictive given typical production variations. So the maximum allowed density variance across a constant thickness is 0.5.