How is distance measurement defined for obstruction criteria?

How is distance measurement defined for obstruction criteria?

• A. Measured from sprinkler center to obstruction center.
• B. Measured from obstruction center to sprinkler center.
• C. Measured along the wall from sprinkler to obstruction.
• D. Measured from sprinkler head to obstruction edge.

Answer: (A)

Distance to obstructions is defined as measured from the center of the sprinkler head to the center of the obstruction. This aligns with the sprinkler’s discharge pattern, which centers on the head, so the closest approach that could block or cut into the spray is best described by the line between the sprinkler center and the obstruction center. Using center-to-center provides a consistent, geometry-based reference that works for any shape or orientation of the obstruction, avoiding variability that would come from measuring to edges or along walls. Measuring to an edge or along a wall could misrepresent the actual interference with the spray pattern, since those distances depend on the obstruction’s shape and position rather than the sprinkler’s coverage footprint.

Distance to obstructions is defined as measured from the center of the sprinkler head to the center of the obstruction. This aligns with the sprinkler’s discharge pattern, which centers on the head, so the closest approach that could block or cut into the spray is best described by the line between the sprinkler center and the obstruction center. Using center-to-center provides a consistent, geometry-based reference that works for any shape or orientation of the obstruction, avoiding variability that would come from measuring to edges or along walls. Measuring to an edge or along a wall could misrepresent the actual interference with the spray pattern, since those distances depend on the obstruction’s shape and position rather than the sprinkler’s coverage footprint.