CRDS

LGR DLT-100 Liquid Water Stable Analyzer (CRDS)

By means of hydrogen and oxygen isotopic composition (δ²H and δ¹⁸O) a number of processes in the field of hydrogeology can be quantified and qualify very well. Furthermore, these stable isotopes provide an insight to hydrological, climatic and ecological processes for local and regional, as well as for larger scales. This may reflect the role of groundwater in river and lake systems, as well as groundwater formations and general precipitation and evaporation processes.

The instrument DLT-100 from Los Gatos Research Inc. allows precise and easy measuring of hydrogen and oxygen isotopes by means of the so-called cavity ring-down spectroscopy through laser absorption. This is done in a 25 cm chamber by a laser beam being mirrored by a high-reflecting mirror again and again. In this case, the laser beam can reach a path length of up to 2500 m. The result is a very good and clear separation of the different adsorption lines of each water molecule, wherein the total occurrence of the individual molecules can be quantified by the magnitude of the absorbance at a wavelength of about 1390 nm. After that, the determined ²HHO, HH¹⁸O and HHO concentrations are converted to ²H/¹H and ¹⁸O/¹⁶O ratios and presented in a subsequent post processing scale relative to the VSMOW.