For combination detectors where sparks could occur in an area not on the optical axis, what adjustment is required?

• A. Increase sensitivity
• B. The distance shall be reduced or detectors shall be added to compensate for angular displacement
• C. Install a backup power supply
• D. Relocate detectors

Answer: (B)

When using combination detectors with an optical sensing path, coverage depends on angle and distance to the potential spark source. If sparks could occur off the optical axis, the detector’s field of view may miss them unless you adjust coverage. The required action is to shorten the distance to the area where sparks may occur or add detectors to cover the angular displacement, so off-axis events fall within the detector’s sensing cone. Increasing sensitivity can raise nuisance alarms, backing up power doesn’t change detection geometry, and simply relocating detectors may help but isn’t as specific as adjusting distance or adding detectors to ensure off-axis coverage.