The Stopped Flow Injection Colorimeter forms a part of the online cloud water chemistry analysis method by the Centre for Ecology and Hydrology. The instrument took cloud water from the UMIST passive cloud sampler in real time, converted nitrates to nitrite using copper-cadmium reductor cartridge and measured the nitrite concentrations. Nitrate concentrations are derived from the nitrite concentrations.
The files containing the data from this instrument may have suffix of .cnd (for online nitrite concentrations), .cno (for online nitrate concentrations) and .cw2 (for batch nitrate concentrations when there is little cloud water for online analysis)