ISO 19579:2006 specifies an alternative method of determining the total sulfur content of hard coal, brown coal, and lignite by high-temperature combustion and infrared absorption using commercially available instruments.
This method has been shown to be applicable to coal samples having an ash yield of less than 40 %.
BS ISO 19579:2006 history
2006BS ISO 19579:2006 Solid mineral fuels - Determination of sulfur by IR spectrometry