Which side of the joint are penetrameters usually placed on?

• A. The side closest to the source
• B. The side farthest from the source
• C. On both sides
• D. On the left side only

Answer: (A)

Penetrameters provide a reference for image quality and exposure in radiographic inspection, so they must be placed on the side of the joint that faces the radiation source. This ensures the penetrameter and the weld area are irradiated under the same exposure conditions and geometry, producing a consistent density on the film that can be used to verify that the test meets the required penetration and IQI criteria. If the penetrameter were placed on the far side, the extra material between the source and the penetrameter would alter the exposure and density readings, making it harder to judge the weld’s integrity. Placing it on both sides isn’t the standard practice unless a specific procedure calls for it.