Potash estimation in soil usign RF technique

Abstract

The paper describes RF spectroscopic technique for soil potash sensing. The system consists of a cell designed and constructed to find the RF response of potash over a frequency range of 10MHz-4GHz. The cell is well shielded so as to make the RF response of potash immune to external electromagnetic interferences. The signal is applied to the potash sample cell using tracking signal generator and the response of the sample is measured using RF spectrum analyzer. The RF spectra thus obtained shows attenuation at specific frequencies and has flat response at other frequencies. The spectra also shows a proportional change in attenuation depending upon the concentration of potash sample. Though it is possible to predict the unknown potash sample concentration by qualitative analysis, a quantitative analysis using multivariate algorithm can be more useful for the development of a better instrumentation. The paper proposes Partial Least Square (PLS) based multivariate analysis system for potash concentration estimation.