Plastics — Phenol-formaldehyde mouldings — Determination of free ammonia and ammonium compounds — Colorimetric comparison method
NORMA vydaná dňa 1.10.1977
Označenie normy: ISO 120:1977
Dátum vydania normy: 1.10.1977
Počet strán: 2
Približná hmotnosť: 6 g (0.01 libier)
Krajina: Medzinárodná technická norma
Kategória: Technické normy ISO
Description / Abstract: Specification of a semi-quantitative method. The content of free ammonia in a moulded article is of importance, when corrosion of metal inserts or contamination in contact with the article has to be considered. Distillation of the aqueous extract from a powdered test portion, coloration of the distillate by reaction with Nessler reagent and comparison of the colour with that of standard matching solutions.