APPLICATION OF PARTIAL LEAST-SQUARES CALIBRATION METHODS IN LOW-RESOLUTION EDXRS

The partial least-squares calibration method was studied on some examp les of EDXRS applications: determination of strontium and iron in samp les of rock, determination of tin in plated deposits, measurements of ash and sulphur in powdered samples of coal and coating thickness gaug ing. The spectra of the PLS predictors and the scatter plots of the lo ad and score vectors are presented and an analysis of their interpreta tion is made. A non-linearity problem which appeared in some cases was approached either by pretreatment of the entry data or modification o f the latent variable. Application of this calibration technique in EX DRS gives two main advantages: (i) it allows systematic factors influe ncing the final results to be included in the calculated model and (ii ) it can provide a new insight into some aspects of the measurement me thodology since the data in the following steps of the calibration pro cedure can be studied and analysed.