Improving the spectral analysis accuracy of turbid solutions in flexible containers based on the CNCM theory

•From the perspective of the condition number of the coefficient matrix theory, the reason for increasing the number of samples in the correction set to improve the accuracy of spectral analysis is explained.•The theory of the condition number of the coefficient matrix is used to inhibit the interferences due to the differences in flexible containers.•It is feasible to increase the number of equations to improve the accuracy of spectral analysis by the multi-pathlength spectrum method.