Influence of the apparatus on the intensity ratio of the measured Raman peaks

[Display omitted] •Intensity ratio of Raman peaks is influenced by the spectral widths of apparatuses.•Intensity ratio of broad peak to narrow one increases with increasing spectral widths.•The spectral resolution should be indicated for the application of intensity ratio. We report an analytic result about the influence of the apparatus on the intensity ratio of the Raman peaks. This ratio of the Raman peak with the larger linewidth to the one with the smaller linewidth will increase with the increasing width of the instrument response function and the linewidth of the incident laser. For the applications of the empirical equations based on the intensity ratio of Raman peaks, the spectral resolution of the instrument should be indicated, and the fitting associated with a measured instrument response function is recommended.