【摘 要】
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Since the gas infrared absorption spectrum linewidth is only several nanometers occupying the source intensity of several in a thousand, it is even less than th
【出 处】
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Semiconductor Photonics and Technology
论文部分内容阅读
Since the gas infrared absorption spectrum linewidth is only several nanometers occupying the source intensity of several in a thousand, it is even less than the noise of light source. The signal of gas absorption is submerged in the noise, so it is impossible to measure the concentration of gas with spectrum absorption directly. According to the principle and parameters of difference absorption system of CH_ 4 gas, a detection circuit consisted of the lock-in amplifier is designed. The experiment results indicated that the detection circuit can satisfy the demand of the whole system, and the limit concentration is 150×10~ -6 .
Since the gas infrared absorption spectrum linewidth is only several nanometers occupying the source intensity of several in a thousand, it is even less than the noise of light source. The signal of gas absorption is submerged in the noise, so it is impossible to measure the concentration of gas with spectrum absorption directly. According to the principle and parameters of difference absorption system of CH 4 gas, a detection circuit consisted of the lock-in amplifier is designed. The experiment results indicated that the detection circuit can satisfy the demand of the whole system, and the limit concentration is 150 × 10 -6.
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