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、火災產生前所釋放之特殊煙霧氣體，以減少財物及人員的傷害為目的。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。本先期研究利用二氧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）修正為線性關係以利於應用。測試結果顯示：可將之利用在偵測低濃度之特定氣體，其相關係數達-0.9039。進一步可針對影響因子，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。

　　　　　This study utilizes the 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 CO?? for calibration, filtered out a range of interest wavelengths, converted and displayed as voltages, and associated with the concentration of CO??. 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 CO?? 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 CO ?? detection reaches -0.9039. Further studies can extend to factors, such as diffusion of gases, locations, environment of the device, and sensitivity to CO?? gas.