Abstract

The shape of contour of absorpsion spectra is affected deeply by experimental conditions such as temperature, pressure...In this paper only tem perature dependence is investigated. The experiments show that the temperature decreases make the shape of contour sharper and sharper. This results in decreas ing the half-width of spectral contours and increasing the maximum optical desity (D max). Therefore, impurities with very low concentration were determined eas ily at low temperature. We carried out the experiments with SF6 at 90K. In order to calculate the concentration which is proportional to the area of contour we use Pascal language.