Wavelength modulation-direct absorption spectroscopy (WM-DAS) was used to investigate absorption line-shape models by measuring the H₂O transition at 7299.431 cm⁻¹ in the ν₁+ν₃ vibrational band perturbed by Ar. The partially Correlated quadratic Speed-dependent Hard-Collision profile (pCqSDHCP) was found to give the best fit with the smallest residuals. The Ar-induced broadening, narrowing coefficients and the absorption coefficients were measured using various profile models with comparisons to pCqSDHCP. The room-temperature pressure dependence of the measured parameters and their differences over the range from 0.3 kPa to 80 kPa (Lorentzian-to-Doppler broadening ratios from 0.06 to 3.5) were studied. The pCqSDHCP was also simulated and fit by the other simplified profiles to further explore the pressure dependence, which compares well with the experimental results. The pressure dependence of the broadening and absorption coefficients for Voigt profile (VP) were analyzed to provide the optimal pressure range when using VP to measure the spectroscopic parameters. The experimental and simulated results allow us to quantify the systematic errors in the pressure broadening and line intensity associated with simplified line shape models.

波长调制直接吸收光谱法（WM-DAS）用于通过测量H至调查吸收线形状模型₂ ö过渡在7299.431厘米^-1在ν ₁ + ν ₃振动带受Ar干扰。发现部分相关的二次速度相关硬碰撞曲线（pCqSDHCP）可以以最小的残差实现最佳拟合。使用各种轮廓模型并与pCqSDHCP进行比较，测量了Ar引起的展宽，收窄系数和吸收系数。研究了所测量参数的室温压力依赖性及其在0.3 kPa至80 kPa范围内的差异（洛伦兹-多普勒展宽比为0.06至3.5）。还对pCqSDHCP进行了仿真，并通过其他简化配置文件进行拟合，以进一步探索压力依赖性，从而与实验结果进行了比较。当使用VP测量光谱参数时，分析了Voigt轮廓（VP）的增宽系数和吸收系数的压力依赖性，以提供最佳压力范围。实验和模拟结果使我们能够量化与简化线形模型相关的压力展宽和线强度的系统误差。