Abstract :
After first discussing the fundamentals of photoelectric spectrometry, the basic essentials of automatic direct reading instruments are reviewed, reference being made to a 3-metre direct reading spectrometer with 30 channels which has been developed as a rapid routine production control unit in the making of non-ferrous alloys. The circuit employs features not previously used in this type of equipment, including a `dekatron¿ counter circuit and a printing recorder to register the counts corresponding to the intensity ratios of the selected spectral lines of the constituent elements being measured. The con centrations are then determined from working curves established experimentally for each measuring channel to give the concentration as a function of the count for the corresponding element.
