At the Tritium Laboratory Karlsruhe (TLK) laser Raman spectroscopy, gas chromatography, mass spectroscopy, calorimetry and ionisation chambers are used to determine the composition of tritium gas mixtures. For the first time a laser Raman experiment was assembled with an actively controlled resonator which yields a 50 times higher Raman signal and with all components (laser, optics, Raman cell and spectrometer) installed inside a glove box. Three gas chromatographs, each with up to six detectors, can determine the gases and their tritiated fractions expected in fusion devices down to the sub-ppm range. Tritium in solids, liquids and gases is determined by means of three calorimeters with a dynamic ranges of up to five orders of magnitude and a lower detection limit of 1 GBq. Since any of these techniques has its shortcomings the best analytical approach is to analyse a sample by more than one method. (C) 2001 Elsevier Science B.V. All rights reserved.