How many penetrameters are used for joints under 10 inches?

• A. One penetrameter may be placed at the joint
• B. Two penetrameters may be placed at the joint
• C. Three penetrameters may be placed at the joint
• D. Four penetrameters may be placed at the joint

Answer: (A)

Penetrameters in radiographic testing serve as image quality indicators to verify that the exposure and resulting film density are within acceptable limits for the weld area. The number and placement of penetrameters depend on the size of the joint being radiographed. When the joint is smaller than 10 inches, a single penetrameter placed at the joint provides a representative check of the entire radiographic exposure for that area. Longer joints can have more variation in attenuation along their length, so additional penetrameters are used to ensure the whole weld area is adequately represented on the film. Therefore, for joints under 10 inches, using one penetrameter is the correct practice.