红外低硫传感器信噪比改善方法研究

Study on improving signal-to-noise ratio of infrared low sulfur sensor

摘要:

低硫的红外探测是一个非常重要的研究领域，但由于红外硫的吸收峰在一个特殊的波段，与人体红外波段重合，所以国外的先进技术大都对中国封锁，而国内的低硫传感器存在交叉吸收误差，检出限不够、检测精度低等缺陷。本文以煤中硫元素的测试为基础，研究采用了电调制热释电红外传感器在测量硫元素过程中存在的以上问题，主要开展了探测器稳定性、恒温测试、气室噪声、滤波等改善传感器信噪比的相关改进设计和实验，并提出了优化的方案，优化后经过实验测试，整个测试系统的信噪比提升近50%，检出限从原来的100ppm提升到近10ppm。低硫测量平均值为0.382%，SD 为0.006%，RSD为1.2%，瓶内RSD 为0.9%。达到了低硫的高精密测试。

Abstract:

Infrared detection of low sulfur is a very important research field. However, because the absorption peak of infrared sulfur is in a special band and coincides with the infrared band of human body, most foreign advanced technologies are blocked from China, while domestic carbon sulfur sensors have the defects of cross absorption error, insufficient detection limit and low detection accuracy. Based on the measurement of sulfur in coal, this paper studies the above problems existing in the measurement of sulfur by using electrically modulated pyroelectric infrared sensor, mainly carries out the relevant improvement design and experiments to improve the signal-to-noise ratio of the sensor, such as detector stability, constant temperature test, gas chamber noise and filtering, and puts forward the optimization scheme. After optimization, it is tested by experiments, The signal-to-noise ratio of the whole test system is increased by nearly 50%, and the detection limit is increased from 100 ppm to nearly 10 ppm. The average value of low sulfur measurement is 0.382%, SD is 0.006%, RSD is 1.2%, and RSD in bottle is 0.9%. High precision test of low sulfur is achieved.