Abstract: A spectrometer which comprises a light source for exciting a sample, and a monochromator whose intensity values, as detected at the output gap, are subjected to further processing in a computer, in conjunction with the associated wavelength values, for the purposes of achieving a large measuring range and a high degree of measuring accuracy is provided with two secondary electron multipliers and a beam splitter which supplies the second secondary electron multiplier with only a small fraction of the radiation issuing from the monochromator. An electronic switch transmits to the computer, by way of an A-D converter, the output of that secondary electron multiplier whose output signal is within the analysable range of levels. The computer causes the monochromator to pass through the measuring range a plurality of times, and individually stores the measurement values which are then processed to form mean values.

Abstract: A glow discharge tube for emission spectral analysis is disclosed. The tube includes an anode cavity which is connected on one side to a carrier gas source and is connected on the other side to a first vacuum pump. The anode cavity is in communication, by way of a restrictor, with a cathode cavity which is connected to a second vacuum pump. The second pump produces a vacuum that is greater than that produced by the first pump. To reduce the margin of error in the accuracy of spectral-analytical tests, the gas pressure in the main cavity is maintained at a constant value by an electronic control which regulates the amount of carrier gas being fed to the anode cavity.