光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2015年
4期
881-884
,共4页
谱线线型函数%吸收光谱%气体检测
譜線線型函數%吸收光譜%氣體檢測
보선선형함수%흡수광보%기체검측
快速、精确地测量微量气体浓度的技术在大气质量分析、环境污染检测等领域具有广泛的用途。在红外光谱检测技术中,气体吸收光谱的谱线线型函数是定量测量气体浓度的一个重要参量,而如何准确和快速地得到气体谱线线型函数值是气体浓度测量中的一个关键问题。首先从理论上分析了谱线线型函数,得出计算谱线线型函数的一般方法及探讨了气体浓度与谱线线型函数峰值之间的关系。然后,利用可调激光器及光谱仪检测系统测量了乙炔在1515~1545 nm波长范围内的吸收光谱,再通过Lambert‐Beer定律计算得到在不同频率下的谱线线型函数峰值,最后利用程序拟合出该波段内气体的谱线线型函数峰值分布曲线,并与Voigt线型函数理论计算值进行了比较,发现理论计算的谱线线型函数峰值仍存在一定的偏差。相比理论计算结果,所提出的检测方法得到的乙炔浓度与真实的乙炔浓度值更加吻合,表明了通过实验确定的谱线线型函数的经验公式可以更好地用于气体浓度的检测。由于利用实验测量值获得了谱线线型函数峰值分布的拟合曲线,因此可以快速准确地计算出所对应的谱线线型函数峰值,从而大大地简化了线型函数的计算过程。实验所获得的数据可应用于光学遥测乙炔气体浓度,且提供的方法也可以应用到其他气体的谱线线型函数峰值的测量中。
快速、精確地測量微量氣體濃度的技術在大氣質量分析、環境汙染檢測等領域具有廣汎的用途。在紅外光譜檢測技術中,氣體吸收光譜的譜線線型函數是定量測量氣體濃度的一箇重要參量,而如何準確和快速地得到氣體譜線線型函數值是氣體濃度測量中的一箇關鍵問題。首先從理論上分析瞭譜線線型函數,得齣計算譜線線型函數的一般方法及探討瞭氣體濃度與譜線線型函數峰值之間的關繫。然後,利用可調激光器及光譜儀檢測繫統測量瞭乙炔在1515~1545 nm波長範圍內的吸收光譜,再通過Lambert‐Beer定律計算得到在不同頻率下的譜線線型函數峰值,最後利用程序擬閤齣該波段內氣體的譜線線型函數峰值分佈麯線,併與Voigt線型函數理論計算值進行瞭比較,髮現理論計算的譜線線型函數峰值仍存在一定的偏差。相比理論計算結果,所提齣的檢測方法得到的乙炔濃度與真實的乙炔濃度值更加吻閤,錶明瞭通過實驗確定的譜線線型函數的經驗公式可以更好地用于氣體濃度的檢測。由于利用實驗測量值穫得瞭譜線線型函數峰值分佈的擬閤麯線,因此可以快速準確地計算齣所對應的譜線線型函數峰值,從而大大地簡化瞭線型函數的計算過程。實驗所穫得的數據可應用于光學遙測乙炔氣體濃度,且提供的方法也可以應用到其他氣體的譜線線型函數峰值的測量中。
쾌속、정학지측량미량기체농도적기술재대기질량분석、배경오염검측등영역구유엄범적용도。재홍외광보검측기술중,기체흡수광보적보선선형함수시정량측량기체농도적일개중요삼량,이여하준학화쾌속지득도기체보선선형함수치시기체농도측량중적일개관건문제。수선종이론상분석료보선선형함수,득출계산보선선형함수적일반방법급탐토료기체농도여보선선형함수봉치지간적관계。연후,이용가조격광기급광보의검측계통측량료을결재1515~1545 nm파장범위내적흡수광보,재통과Lambert‐Beer정률계산득도재불동빈솔하적보선선형함수봉치,최후이용정서의합출해파단내기체적보선선형함수봉치분포곡선,병여Voigt선형함수이론계산치진행료비교,발현이론계산적보선선형함수봉치잉존재일정적편차。상비이론계산결과,소제출적검측방법득도적을결농도여진실적을결농도치경가문합,표명료통과실험학정적보선선형함수적경험공식가이경호지용우기체농도적검측。유우이용실험측량치획득료보선선형함수봉치분포적의합곡선,인차가이쾌속준학지계산출소대응적보선선형함수봉치,종이대대지간화료선형함수적계산과정。실험소획득적수거가응용우광학요측을결기체농도,차제공적방법야가이응용도기타기체적보선선형함수봉치적측량중。
The methods that can rapidly and precisely measure concentrations of various gases have extensive applications in the fields such as air quality analysis ,environmental pollution detection ,and so on .The gas detection method based on the tunable laser absorption spectroscopy is considered a promising technique .For the infrared spectrum detection techniques ,the line shape function of an absorption spectrum of a gas is an important parameter in qualitative and quantitative analysis of a gas .Specifical‐ly ,how to obtain the line shape function of an absorption spectrum of a gas quickly and accurately is a key problem in the gas de‐tection fields .In this paper we analyzed several existing line shape functions and proposed a method to calculate precisely the line shape function of a gas ,and investigated the relation between the gas concentration and the peak value of a line shape function . Then we experimentally measured the absorption spectra of an acetylene gas in the wavelength range of 1 515~1 545 nm with a tunable laser source and a built‐in spectrometer .With Lambert‐Beer law we calculated the peak values of the line shape function of the gas at the given frequencies ,and obtained a fitting curve for the line shape function in the whole waveband by using a com‐puter program .Comparing the measured results with the calculated results of the Voigt function ,we found that there was a de‐viation between the experimental results and the calculated results .And we found that the measured concentration of the acety‐lene gas by using the fitting curve of the line shape function was more accurate and compatible with the actual situation .Hence , the empirical formula for the line shape function obtained from the experimental results would be more suitable for the concentra‐tion measurement of a gas .As the fitting curve for the line shape function of the acetylene gas has been deduced from the experi‐ment ,the corresponding peak values of the spectral lines can be immediately calculated out from the curve and used for the meas‐urements of different concentrations of acetylene gases .Therefore ,the calculation for the line shape function values is greatly simplified .The obtained data of the line shape function of the acetylene gas can be used for remote sensing of the gas ,and the proposed method can also be applied for the measurements of line shape functions of other gases .