Industrial Radiography Operations and Equipment
Equipment you must be able to describe
A gamma exposure device (camera) holds a sealed source in a shielded position. The source assembly attaches to a drive cable and pigtail, travels through a guide tube, and is collimated at the workpiece. Know the lock, the port, the source-position indicator, the crank or remote control, and the storage container. X-ray units are rated by kVp (penetration) and mA (output), with focal-spot size driving geometric unsharpness.
Operating discipline
Survey the area and post boundaries before exposure, keep the source under surveillance, collimate to reduce scatter, use a survey meter to confirm the source is shielded after every exposure, and never assume crank position, cable markings or the indicator prove the source is retracted. Store devices locked, labeled and secured, with the source in the shielded position.
Traps
Trusting the crank or drive cable instead of a survey. Forgetting that backscatter and collimation change the boundary. Mixing up source-to-film distance effects with exposure time.
Worked example (rule of thumb)
Ir-192 delivers about 0.48 R/h per curie at 1 m; Co-60 about 1.3 R/h per curie at 1 m. For 30 Ci Ir-192: 30 x 0.48 = 14.4 R/h at 1 m. At 30 m, apply inverse square: 14.4 / 900 = 16 mR/h. Setting a 2 mR/h boundary means finding the distance where the rate falls to 2 mR/h - here about 85 m - then posting well beyond it.