GAS DETECTOR AND GAS DETECTING APPARATUS

PROBLEM TO BE SOLVED: To facilitate the simplification of the constitution of a gas detecting apparatus and the reductions of its size and dissipation power and to detect a plurality of gases by using one pyroelectric infrared sensor. SOLUTION: An Si micro light source 3 emits a detecting infrared light LIR into a gas detecting cell 2. Filter means 4 transmits the light LIR of previously set plurality of absorption wavelength bands. A pyroelectric infrared sensor 5 receives the light LIR transmitted through the means 4 and outputs a detection signal S. Accordingly, it can output the signal S corresponding to the presence or absence of the gas to be detected. Since the source 3 emits the pulse-like detecting infrared light, a chopper and the like are eliminated, reduced in size, and in dissipation power. Pulse power supply means 11 supplies a pulse power to the source 3. Discriminating means 12 discriminates the presence or absence of the gas to be detected based on the output signal S, and hence the presence or absence of the gas to be detected can be effectively and accurately discriminated.