Air quality monitoring: mercury in precipitation

The wet-only precipitation collector samples precipitation only when it rains or snows. During precipitation events sensors located on the collector automatically signal the roof to uncover a glass funnel which is connected to a bottle charged with one percent hydrochloric acid. The sampling train is specially designed and treated to preserve Mercury and each week the entire sampling train is replaced with a new clean mercury free sampling train. CAPMoN uses a N-CON Systems wet deposition mercury sampler to collect precipitation and a Nipher Shielded NOAH IV electronic rain gauge to estimate precipitation depth.
The samples are integrated over 7 days and collected by a site operator at 08:00 every Tuesday morning and immediately shipped to the laboratory for analysis. CAPMoN samples are collected using the same protocols as the U.S. Mercury Deposition Network (MDN) and analysed in the same laboratory as MDN.