90.92 Standard to be revised May 20, 2023
ISO
ISO/TC 27/SC 5 Methods of analysis
International Standard
73.040 Coals
Published
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.
WITHDRAWN
ISO 7404-4:1988
PUBLISHED
ISO 7404-4:2017
90.92
Standard to be revised
May 20, 2023
IN_DEVELOPMENT
ISO/DIS 7404-4