水汽吸收分布于整个中红外波段,它的存在干扰红外光谱的定量分析。文章介绍了一种从傅里叶变换红外光谱仪的测量数据中扣除水汽干扰信号的新方法。该方法首先通过气象参数测量获得气压、温度和相对湿度,结合HITRAN数据库中提供的水汽线强、自展宽、空气展宽等参数,使用逐线积分方法计算出高分辨率水汽吸收谱,再通过仪器线型订正,合成出与仪器分辨率相匹配的水汽谱,将其作为干扰组分直接从测量所得到的含有水汽的混合光谱中扣除。对开放光程FTIR系统的实测数据的分析结果表明,使用该方法可以有效消除水汽干扰,扣除后的光谱包含待测组分的吸收特征和噪声。在开放光程FTIR等无法使用干燥设备去水的观测条件下,使用该方法可以达到较理想的水汽扣除效果。 Water vapor absorption distribution in the entire mid-infrared band, its presence interferes with the quantitative analysis of infrared spectroscopy. In this paper, a new method of subtracting the water vapor interference signal from the measured data of Fourier transform infrared spectrometer is introduced. The method first obtains the barometric pressure, the temperature and the relative humidity by means of the meteorological parameter measurement. The water vapor intensity provided in the HITRAN database is used to calculate the high-resolution water vapor absorption spectrum by using parameters such as water broadening and air broadening, A linear correction was made to synthesize a vapor profile that matches the resolution of the instrument and was subtracted directly from the measured moisture-containing mixed spectrum as an interfering component. The analysis of the measured data of the FTIR system shows that this method can effectively eliminate the interference of water vapor and the subtracted spectrum contains the absorption characteristics and noise of the tested components. In the open optical path FTIR can not use drying equipment to water observation conditions, the use of this method can achieve better water vapor deduction.