What procedure is described where one operator directs a bright light down a line while another observes from above, sometimes using a mirror?

• A. Dye Test
• B. Smoke testing
• C. Procedure for lamping
• D. Deflection Test: Go - No Go Test

Answer: (C)

Lamping is a visual inspection method in which a bright light is sent down a sewer line and an observer watches from above, often using a mirror to see reflections or the far end of the line. This setup lets you visualize how the line carries light through bends and joints, helping identify obstructions, misalignments, cracks, or root intrusion by the glow, shadows, or any light leakage you can observe from above. It’s the technique that matches the description of directing light down the line with someone watching from the surface and sometimes using a mirror to aid the view.

Dye tests involve introducing colored dye to trace flows, not light transmission. Smoke testing uses smoke to reveal leaks, not a light-based viewing method. The deflection test measures how much a pipe deflects under pressure or loading, rather than inspecting with light.