What technique determines rough limits of contamination?

• A. Grid.
• B. Course Leg.
• C. Star.
• D. Zig-zag monitoring.

Answer: (C)

Mapping rough limits of contamination is about quickly determining where the contamination stays above the limit. The star approach does this by taking measurements along several straight lines radiating out from the suspected source, creating a star-like pattern. By noting on each ray where the readings drop below or rise above the threshold, you can sketch a rough boundary of the contaminated area.

This method is efficient for an initial survey because it covers multiple directions with relatively few measurements, giving a usable boundary fast. In contrast, a dense grid requires many points to define the outline, zig-zag monitoring can miss the true edge if the contour isn’t aligned with the path, and a single linear pass (course leg) isn’t designed to capture spread in all directions.