For radiographic testing with hole-type IQI, which hole size must be visible?

For radiographic testing with hole-type IQI, which hole size must be visible?

• A. 1T
• B. 2T
• C. 3T
• D. 4T

Answer: (B)

In radiography, a hole-type IQI is used to prove the technique has enough sensitivity to reveal flaws of a known size. The four holes are sized as 1T through 4T, and the requirement is that the 2T hole be clearly visible on the radiograph. This establishes that the exposure and film processing conditions are capable of resolving a hole of that size, which corresponds to the minimum detectable flaw level for the test. If the 2T hole isn’t visible, the radiograph can’t be considered to have adequate sensitivity, even if larger holes (3T or 4T) are visible. The 1T hole is usually too small to rely on for consistent verification, so the standard targets the 2T hole as the minimum acceptable visibility.

In radiography, a hole-type IQI is used to prove the technique has enough sensitivity to reveal flaws of a known size. The four holes are sized as 1T through 4T, and the requirement is that the 2T hole be clearly visible on the radiograph. This establishes that the exposure and film processing conditions are capable of resolving a hole of that size, which corresponds to the minimum detectable flaw level for the test. If the 2T hole isn’t visible, the radiograph can’t be considered to have adequate sensitivity, even if larger holes (3T or 4T) are visible. The 1T hole is usually too small to rely on for consistent verification, so the standard targets the 2T hole as the minimum acceptable visibility.