The fire detector provides a reliable early warning of a fire condition that responds to a fixed threshold of smoke concentration detected in protected premises. Sensitivity to smoke (low, medium or high) complies with the European standard EN54-7 and is programmable by the IFS7002 fire control panel. The fire detector operates on an improved algorithm for self-compensating for contamination from the optical chamber, indicating the need to dust the chamber. It is done quickly due to the easy disassembly and assembly of the body cover. The construction of the optical chamber and the technology used in the manufacture of the screen provides high-level protection against the ingress of dust particles and insects and working under strong air flow.