| 摘要 |
A gas detection method and a gas sensor are provided to discriminate a target gas with a spread spectrum. A photo acoustic near infrared gas sensor comprises at least one amplitude modulation laser source(1), a gas chamber(5) receiving a target gas, a microphone(3) attached to the gas chamber, an optical detector(6) detecting light intensity of the laser source and a processing unit(15) including a modulation frequency generator(9) supplying a modulation signal for the laser sources and controller(8,12,13,14) determining gas concentration.
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