NIR reflectance spectrum errors of mineral samples and processing methods

During the process of measuring Near Infrared (NIR) diffuse reflectance spectra of the mineral samples by using a portable NIR spectrometer PISA, there are some errors, they made the spectra show: different spectrum data of the same component samples. These errors will result the inaccurateness of mineral contents NIR analysis. So in order to decrease the errors, the two work had been done. (1) The error sources were found by means of the instrument structure and sample features analysis. They are the instability of instrument and nonuniformity of sample properties. (2) The different mothed were used in terms of the error characteristics. A wavelet baseline-correction method was utilized to reduce the random error in spectra; a wavelet de-noising method was used to restrict the noise. The experiments show that the above methods are effective for processing field mineral NIR spectrum.