非發散式紅外線氣體感測器之設計與應用

Design and Implementation of Non-Dispersive Infrared Gas Sensor

李奕賢(Yi-Hsien Li)

指導教授 ： 林致廷

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201804258

摘要

為了解決現有的二氧化碳(CO2)感測器所面對的問題，包含金屬氧化物的高功耗、需要預熱以及量測溫度高的問題以及高分子材料的複雜製程、使用期限短和濕度敏感等問題，我們使用窄波段光源搭配超窄波段的帶通濾波片以及熱堆感測器來製作可室溫操作的光學氣體感測器。我們在架設此一光學感測器時，先後克服了感測器的升溫、氣流影響量測訊號、量測時間過長以及量測訊號穩定性的問題，並輔以量測軟體進行數據紀錄而做出了一個良好的光學氣體感測器。此感測器可以在CO2濃度為500ppm ~ 5000ppm有著良好的反應、可重複性以及較長的使用期限。這樣的感測範圍適合用在一般室內的空氣品質檢測，以警示CO2濃度過高的狀況。一般環境下的CO2濃度為400ppm，室內濃度則建議在1000ppm以下；如果長期處於CO2濃度大於1000ppm的情況，輕則可能會產生頭暈，嚴重則可能會造成缺氧、腦損傷甚至死亡。

關鍵字

二氧化碳 ； 窄波段光源 ； 帶通濾波片 ； 熱堆感測器 ； 光學感測器

並列摘要

To solve the nowadays difficulties, such as high power consumption, need of preheating and high measuring temperature of metal oxide sensors；complex manufacturing, short lifetime and moisure sensitive of organic sensors, we use a narrow bandwidth light source with a 200nm bandwidth filter and a thermopile sensor to make it as a moderate-temperature optical gas sensor. As we constructed such sensor, we overcame the problems such as temperature issue, flow rate issue , long measuring time and signal stability, and with a measuring software to record the data to make it a sensitive optical gas sensor. This sensor can detect the CO2 concentration between 500ppm and 5000ppm, and it shows the sensor has a good response, repeatibility and long lifetime. It is suitable for indoor air quality monitoring. In general, the CO2 concentration is 400ppm, and indoor concentration is lower than 1000ppm.If exposed in an environment which CO2 concentration is over 1000ppm for a long time, people may be uncomfortable even dead.

並列關鍵字

CO2 ； narrow band light source ； narrow band filter ； thermopile sensor ； optical sensor

參考文獻

[1]http://law.isha.org.tw/isha_law/Pages/LawList.aspx?Lawid=055

[2]Yi Jun Liu, Andreas Mandelis, and Xinxin Guo, “An absolute calibration method of an ethyl alcohol biosensor based on wavelength modulated differential photo thermal radiometry,” Review of Scientific Instruments, November 2015

[3]Henfling, M., Gossner, U., Kutter, C., Hansch, W., & Trupp, S. (2017). Simultaneous optical and electrical CO2 detection in one sensitive film. Sensors and Actuators B: Chemical, 241, 1256-1260.

[4]Lochman, L., Zimcik, P., Klimant, I., Novakova, V., & Borisov, S. M. (2017). Red-emitting CO2 sensors with tunable dynamic range based on pH-sensitive azaphthalocyanine indicators. Sensors and Actuators B: Chemical, 246, 1100-1107.

[5]Liu, X., Cheng, S., Liu, H., Hu, S., Zhang, D., & Ning, H. (2012). A survey on gas sensing technology. Sensors, 12(7), 9635-9665.