The smoke detector works on the principle that infrared scatters in the smoke toprobe the smoke which is generated by the incomplete combustion at the initial stageof the fire. It consists of photoelectric system, signal processing identificationcircuit and alarm circuit. The infrared scatters on the surface of the smokewhen the smoke enters the darkroom of the detector, then the photoelectricdiode receives the scattered light and generates the photoelectric signal current.The photoelectric signal generates the alarm signal after being processed byThe household gas alarm is developed by adopting advanced electronic techniques andgas detecting techniques. It is of high sensibility and is applicable to detectingthe leakage of household gas, liquid gas and natural gas. The sensor reactswith the diffused gases in the air directly and generates linear voltage signal.When the detected gas density reaches a setting value, the alarm will send outacousto-optic alarm signal to remind users to take measures in time. producing area:China payment:30% T/T in advance, L/C at sight