Beam Detector Spacing Calculator

Design projected beam smoke detection per NFPA 72.

Maximum listed path length (typical: 330-500 ft)

NFPA 72 Beam Detector Requirements

  • Max spacing: 60 ft between beams (smooth ceiling)
  • Max wall distance: 30 ft (half of spacing)
  • Height: 4 in to 24 in below ceiling typical
  • Compensate for stratification above 30 ft
  • Consider beam path obstructions
  • Auto-alignment recommended for long ranges