一種經濟型紅外線高感度二氧化碳氣體偵測器之製作

Making and Evaluation for an Economic Type of Infrared-active CO2 Gas Sensor

廖峻德(Jiunn-Der Liao) ； 劉光弘(Kuan-Hong Liu) ； 許迪竣(Di-Jiun Shu) ； 曹拯元(Jen-Yuan Chaw) ； 陳玉惠(Yui-Whei Chen)

《中原學報》 28卷3期 (2000/09) Pp. 103-107

https://doi.org/10.6358/JCYU.200009.0103

摘要

利用氣體對應於可被不同波長之紅外光的吸收特性，應用於材料受不同程度燃燒後釋出煙霧成分與濃度之量測，以早期偵測低濃度、火災産生前所釋放之特殊煙霧氣體，以減少財物及人員的傷害爲目的。對於火源的位置而言，時間的把握是非常重要的因素。而將感測裝置小型化有利於探測位置較不受空間因素及取樣數的影響。本先期研究利用二氣化碳分子吸收特定波長紅外光的特性做校正，將此波長範圍加以過濾出，轉換成以電壓顯示，達到快速檢測出非常態二氧化碳的濃度。基於此原理與方法，選擇適當的濾片，亦可檢測其它紅外光可吸收氣體。本原型裝置對二氧二化碳做校正，經實驗室級測試，將濃度與輸出電壓值（紅外線感測的強度）修正爲線性關係以利於應用。測試結果顯示：可將之得用在偵測低濃度之特定氣體，其相關係數達-0.9039。進一步可對影響因子，如：氣體擴散、放置地點、操作環境、及對二氧化碳靈敏度做評估。

關鍵字

氣體偵測器 ； 紅外光 ； 二氧化碳 ； 低濃度

並列摘要

This study utilizes characteristic of specific gas corresponding to its sensitivity of infrared absorption peaked at a particular wavelength number, which applies to detect gaseous molecule for a material bearing different degrees of burning and then measures the composition and concentration of released mass. Present device aims to conduct early detection of specific gas at low concentration and typical byproducts, correlate to the likely occurrence of fire, and reduce the loss of properties and lives. Concerning about the location before provoking flames, to hold the time factor is of great significance. Consequently, miniature gas sensing device takes the advantages of independent from dimension of detection and of sampling numbers. This developed infrared gas sensor used CO2 for calibration, filtered out a range of interest wavelengths, converted and displayed as voltages, and associated with the concentration of CO2. Experimental result of this prototype gas-sensing device has demonstrated a modified linear relationship between output voltage (correlated with the intensity of infrared absorbance) and calculated CO2 concentration, which could be integrated for further applications. Our testing result also indicates a feasible approach to detect low concentration of specific gas. The correlation coefficient for CO2 detection reaches -0.9039. Further studies can extend to factors, such as diffusion of gases, locations, environment of the device, and sensitivity to CO2 gas.

並列關鍵字

Gas sensing device ； Infrared ； CO2 ； low concentration