The 58000-650IMC is an addressable optical (photoelectric) smoke detector, part of the Context UL-Plus range, using the Discovery / Xpert protocol for communication. It’s UL-Listed and designed for intelligent fire alarm systems. It uses a white polycarbonate housing with wind-resistant smoke inlets and a flashing LED indicator. Smoke is detected via a pulsing infra-red LED inside a baffled chamber; smoke particles scatter the light onto a photodiode, which then triggers an alarm when threshold is exceeded. The detector also integrates signal processing, addressing electronics, and communications circuitry. Key Features: Supports 17–28 V DC supply, two-wire addressable loop, polarity insensitive; Quiescent current ~340 µA average (with peaks to ~600 µA); Optical sensitivity: typically triggers at ~2.4% smoke obscuration per meter; Flashing LED option & 360° visibility alarm indicator for clear visual alerts; Five selectable response modes to adapt to environment (e.g. clean, dusty, humid); Drift compensation built in — automatically adjusts sensitivity over time to mitigate dust accumulation; Operating temperature: –20°C to +60°C; Humidity tolerance: 0% to 95% RH without condensation / icing; IP43 (secures some protection from intruding objects / moisture); Compact size & weight: ~100 mm diameter × 42 mm height; ~105 g device weight. Industrial Uses / Applications: Commercial / office buildings — corridors, lobbies, escape routes; Residential complexes & apartment blocks; Hotels, schools, hospitals; Warehouses, retail stores; Any fire detection system using addressable loops and requiring early smoke detection.