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Status : Withdrawn
Standard Type : Main
Document No : ISO 7404-4:2017
Document Year : 2017
Pages : 9
Edition : 2
Section Volume : Methods of analysis (ISO/TC 27/SC 5.)
ISO 7404-4:2017 specifies a method, using a graticule with 20 crossline intersections, for determining the proportions of microlithotypes, carbominerite and minerite in coals. It applies only to determinations made on polished particulate blocks using reflected white light (about 400 nm to 700 nm). Additional blue, blue-violet or UV light excitation (365 nm to 440 nm) for better identification of liptinite in fluorescence may be used especially at low rank coals.