Multisensor fire detector with integrated optical sensor and heat sensor with enhanced false alarm management. The optical measurement chamber is provided with a patented developed sensor technology using a high-sensitive blue LED (instead of the commonly used red LED in Optical smoke detectors), enabling the detection of open fires, smoldering fires and fires with high heat generation. Especially for open fires, the classical ionization technology implemented in ionization detectors is replaced by the unique detection technology, unlike ionization detectors, this sensor works without a radioactive element which causes problems at the time of refuse disposal. The detector is capable of identifying the TF1 and TF6 test fires described in the EN 54-9:1982 specification. Well suited for sensitive environment, detection of invisible up to large aerosols. The OT^blue multisensor is an intelligent detector with time-related signal analysis, signal correlation of the sensor data, decentralized intelligence, automatic function self-test, CPU failure mode, automatic adaptation to environmental conditions, alarm and operating data memory, alarm indicator and soft-addressing. The detector is provided with an integrated isolator and a remote indicator can be connected.