2012VDI 3869 Blatt 4-2012 Measurement of ammonia in ambient air - Sampling with diffusive samplers - Photometric or ion chromatographic analysis
2010VDI 3869 Blatt 4-2010 Messen von Ammoniak in der Aussenluft - Probenahme mit Passivsammlern - Fotometrische oder ionenchromatografische Analyse
1996VDI 3869 Blatt 4-1996 Measurement of acids and bases in ambient air - Measurement of ammonia; sampling in diffusion separators coated with citric acid - Determination by indophenol method