The EA converts carbon contained in organic (soil, plant material, specific compounds etc.) samples into CO₂. The sample material is weighed into tin or silver boats and burned at 950 ° C in a combustion tube in a constant stream of helium with the addition of oxygen. Resulting combustion gases (CO, CO₂, NO, NO_x, H₂O, etc.) are then completely oxidized by copper oxide contained in the combustion tube, e.g. CO to CO₂. Pieces of copper wire in the reduction tube reduce excess oxygen to copper oxide and nitrogen oxides are converted to nitrogen. The resulting gas mixture (CO₂, H₂O, N₂) is separated by chromatography, so that pure CO₂ is obtained in a helium stream. Depending on the sample size, this is either graphitized in the AGE or, after direct concentration in the GIS, measured as a gas sample with the MICADAS.