Osservazioni sulla sensibilità di riconoscimento spettrale delle impurità nel piombo

Abstract

Using a spark source we have ascertained the limit of detection of the various impurities in lead and have then taken into consideration the ratios between the values obtained for the various elements and the value obtained for the impurity Cu. They have been found in good accordance with the average of similar ratios derived from other published work. Having thus verified the presence of considerable differences in the limits of detection of the various elements, we subdivided the elements under consideration into three classes corresponding to the classes of Hume-Rothery's description of the periodic system and examined then the variations in sensitivity in the first and third class. In the first class the sensitivity follows the order of the heats of vaporisation. As to the elements of the third class, the particularly low sensitivity is probably due to the position of the ultimate lines in Schumanns U.V.