Abstract: To determine the carbon black distribution two measurements of spectral intensities of separately produced plasmas are carried out with different time delays relative to a particular laser pulse, the time delay for the second measurement for determining the spectral line intensities of a reference element carbon (I.sub.C') and at least one analysis element (I.sub.A.n') being smaller than for the first measurement; for determining the spectral line intensities of the reference element (I.sub.C) and the other analysis elements (I.sub.A.n).Evaluation of the measurements is performed by reference to calibration information based on reference measurements, which information shows the magnitude of the concentration ratio of the other analysis elements or the at least one analysis element to the reference element (c.sub.A.n /c.sub.C or c.sub.A.n /c.sub.R) as a function of the appurtenant intensity ratio values.

Abstract: To determine the carbon black distribution two measurements of spectral intensities of separately produced plasmas are carried out with different time delays relative to a particular laser pulse, the time delay for the second measurement for determining the spectral line intensities of a reference element carbon (I.sub.C,) and at least one analysis element (I.sub.A.n,) being smaller than for the first measurement; for determining the spectral line intensities of the reference element (I.sub.C) and the other analysis elements (I.sub.A.n).Evaluation of the measurements is performed by reference to calibration information based on reference measurements, which information shows the magnitude of the concentration ratio of the other analysis elements or the at least one analysis element to the reference element (c.sub.A.n /c.sub.C or c.sub.A.n /c.sub.R) as a function of the appurtenant intensity ratio values.

Abstract: A method of analyzing elements of a metal melt contained in a melting vessel comprises the following steps: introducing an inert gas at a temperature in excess of 300.degree. C. laterally into a tube passing through a lateral wall of the melting vessel and opening thereinto; generating a laser beam; passing the laser beam through an adjustable first lens system; reflecting the laser beam by a mirror into the tube; guiding the laser beam through a quartz window which closes the tube; generating a plasma in the tube by focusing the laser beam by the adjustable first lens system onto the surface of the metal melt in the tube; guiding the light generated by the plasma through the quartz window to an adjustable second lens system; coupling the light by the adjustable second lens system with an optical waveguide; and introducing the light by the optical waveguide into a spectrometer.

Abstract: A polychromator in a Paschen-Runge mounting in which intensity measurements are made by means of a row of photodiodes. The spectral intensity distribution of at least two spectral regions on the Rowland circle is transmitted to the row of photodiodes by image conductors and is measured there.