Fire or Smoke Detector with High False Alarm Rejection Performance

摘要

An apparatus for detecting a hazardous condition includes an optical module for measuring scattered light caused by the hazardous condition, a temperature sensor, a humidity sensor, and a processing unit coupled to receive signals from the optical module, the temperature sensor and the humidity sensor. The processing unit processes the signals to determine criteria to distinguish deceptive phenomena from a hazardous condition in order to limit false alarm. The processing unit is uses the criteria for adjusting an alarm threshold value that is a function of a reference function, a function based on temperature criteria, a function based on at least one of the temperature criteria and a ratio criterion, and a function based on humidity criteria.