A microprocessor controlled hazardous condition detection system with volatile and non-volatile memory containing a sensor package, the sensor package containing sensors exposed to the ambient environment, and an alarm element coupled to the sensor package through a microprocessor where the microprocessor includes a memory storage device containing a plurality of alarm thresholds stored therein, each of the plurality of alarm thresholds being associated with a predetermined set of levels in the ambient environment where the microprocessor receives periodic readings from the sensor package, the microprocessor conditions the received readings by removing a selected amount of noise and attenuation therefrom, selects and employs an optimized alarm threshold from a plurality of stored alarm thresholds and activates the alarm element upon detecting a threshold levels in the ambient environment greater than the selected alarm threshold.