In a paper published by the Integrated Carbon Observation System (ICOS), the drift performance of 47 Picarro analyzers of 3 different generations were compared (Yver Kowket al, Atmos. Meas. Tech. Discuss., 8, 4219–4272, 2015). The results show that methane drift (the minimum of the Allan standard deviation) was much better in first-generation G1000 analyzers.
Our initial assessment concluded that the source of the drift is the pressure sensor system.In parallel with this investigation, and in response to demanding ICOS specifications for reproducibility for CO measurements, we implemented software and hardware updates resulting in our standard production G2401 analyzer exceeding these requirements.