For analyzing hydrogen and oxygen isotopes of water in solids, liquids or the vapor phase, the CRDS technique (Cavity Ringdown Spectroscopy, Fa. Picarro Inc.) is used. This technique is field deployable, and may be used for micro amounts of water, as it needs only a few μl per injection. The ISOLAB FACILITY of the AWI in Potsdam is equipped with five cavity ring down spectrometers operating in different measuring modes. Two devices are located at joint MPI-AWI Isotope Lab in Yakutsk and …