The gas mole fraction analyzer (Picarro G2401) can perform precise measurement of carbon monoxide (CO), carbon dioxide (CO2), methane (CH4) at parts-per-billion (ppb), and water (H2O) vapor at parts-per-million (ppm) sensitivity simultaneously. It meets the ICOS performance requirements for CO, CO2, and CH4 atmospheric monitoring. At the ICOS tower located in Tito (PZ) air sampling will be made at 10, 50, 100 m.