Nonlinearity parameter in the pathlength dimension to improve the scattering in the transmission spectra.

In spectrochemical quantitative analysis of solutions containing scattering components, the spectral nonlinearity caused by scattering seriously affects the prediction accuracy, robustness, and even feasibility of the models. Unlike the traditional methods (modeling with the spectra data of single pathlength) of approximating the nonlinear spectral line to linear to reduce the nonlinear features of scattering, a new method is proposed to reduce the effect of scattering by taking advantage of the nonlinear characteristics of spectral lines. First, the logarithmic function is used to fit the attenuation of multiple pathlengths, then the regression coefficient of the function is taken as the characteristic parameter of scattering, and the wavelengths with smaller characteristic parameter are selected as the modeling wavelengths.

Higher precision integer operations instead of floating-point operations in computers or microprocessors.

The rounding errors of floating-point operations are inevitable in computers or microprocessors, and this issue will make the calculation results inaccurate, unreliable, or even completely incorrect. For this purpose, this paper proposes to replace floating-point operations with integer operations to improve the operation precision. The key lies in not only controlling the variable type as the integer to avoid the automatic conversion of intermediate operation results into floating-point numbers but also converting floating-point operations in the operation process into integer operations using some numerical calculation methods.

A method to eliminate the influence of incident light variations in spectral analysis.

The intensity of the light source and consistency of the spectrum are the most important factors influencing the accuracy in quantitative spectrometric analysis. An efficient "measuring in layer" method was proposed in this paper to limit the influence of inconsistencies in the intensity and spectrum of the light source. In order to verify the effectiveness of this method, a light source with a variable intensity and spectrum was designed according to Planck's law and Wien's displacement law.

Quantitative determination based on the differences between spectra-temperature relationships.

In the Near-infrared (NIR) spectral measurement it is not always possible to keep the experimental conditions constant. The fluctuations in external variables, such as temperature, will result in a nonlinear shift and a broadening of the spectral bands. In this study, the temperature-induced spectral variation coefficient (TSVC) was obtained by using loading space standardization (LSS).