SMOKE ALARM Russian patent published in 2002 - IPC

FIELD: smoke alarms with scattered light. SUBSTANCE: proposed smoke alarm has insert with optical module anchored in base. Module incorporates light source, light detector, measurement chamber, bottom and labyrinth system with blends placed over periphery of measurement chamber. Bottom has shape of funnel, cone or pyramid. Thanks to such arrangement dust particles deposited on bottom are markedly remote from measurement zone as compared with previous design which notably diminishes probability of light scattered over particles of dust hitting measurement zone. EFFECT: increased protection against false operation. 7 cl, 2 dwg