Which distance measurement is used for obstruction criteria?

Which distance measurement is used for obstruction criteria?

• A. From obstruction center to sprinkler center
• B. From sprinkler center to obstruction center
• C. From obstruction edge to sprinkler face
• D. From sprinkler head to obstruction edge

Answer: (B)

The obstruction criteria use a center-to-center measure: from the sprinkler center to the obstruction center. This standard approach aligns with how the sprinkler’s discharge pattern is centered on its deflector, so the potential blocking effect of an obstruction is evaluated based on how close its center lies to the sprinkler’s center, not on the obstruction’s size or edge. If you measured from the obstruction edge or from the sprinkler face, the result would vary with the shape or width of the obstruction, making the assessment inconsistent across different objects. Center-to-center provides a consistent, shape-independent basis for determining whether an obstruction is close enough to affect coverage.

The obstruction criteria use a center-to-center measure: from the sprinkler center to the obstruction center. This standard approach aligns with how the sprinkler’s discharge pattern is centered on its deflector, so the potential blocking effect of an obstruction is evaluated based on how close its center lies to the sprinkler’s center, not on the obstruction’s size or edge.

If you measured from the obstruction edge or from the sprinkler face, the result would vary with the shape or width of the obstruction, making the assessment inconsistent across different objects. Center-to-center provides a consistent, shape-independent basis for determining whether an obstruction is close enough to affect coverage.