Andersen, H.V., Løfstrøm, P., Moseholm, L., Ellerman, T. & Nielsen, K.E. 2009. Metodeafprøvning af passive diffusionsopsamlere til koncentrationsbestemmelse af ammoniak. Danmarks Miljøundersøgelser, Aarhus Universitet. 31 s. Faglig rapport fra DMU nr. 730.
Measurements of atmospheric ammonia concentrations by two types of passive diffusion tube samplers (ALPHA and Radiello) have been compared to active measurements obtained by the denuder method. The comparison was made at several locations over a one year period, covering different concentrations levels and seasons. The passive diffusions tube samples were found suitable for fortnight to monthly sampling. Both types of passive diffusion tubes showed a small systematic overestimation of the ammonia concentration compared to the denuder tubes and therefore demand a correction. The precision is good and both types of tubes are suitable for measuring local gradients. Since the passive diffusion tubes are independent of power supply, they are very suitable for monitoring purposes.
Full report in Danish in PDF-format (6.3 MB).
