<p>The reliability of photoelectric-type smoke detectors, widely employed for early fire detection in buildings, is often compromised due to frequent false alarms triggered by nuisance aerosols. While multi-sensor detectors offer improved discrimination, their implementation remains limited. To overcome these issues, the present study investigates the light scattering characteristics of smoke particles and nuisance aerosols using a light-scattering chamber (LSC) specifically designed to retain the simplicity of conventional photoelectric-type smoke detectors. The LSC features a single light source and multiple photodetectors strategically positioned at 12 uniformly distributed angles to capture scattering phenomena. The analysis revealed distinct scattering behaviors between smoke particles and nuisance aerosols. Specifically, smoke particles predominantly produce backward scattering, where light is scattered opposite to the propagation direction. In contrast, nuisance aerosols exhibit pronounced forward scattering. This difference can be attributed to particle size–dependent differences in light absorption and transmission. From a practical standpoint, it was demonstrated that using only two photodetectors positioned to capture forward and backward scattering angles is sufficient to effectively distinguish between particle types. This finding suggests that conventional photoelectric-type smoke detectors can achieve significantly enhanced particle differentiation capabilities with a simple structural modification that incorporates an additional photodetector. This approach holds substantial promise for improving the reliability and performance of fire detection systems while maintaining their cost-effectiveness and simplicity.</p>