TS 5474

TS 5474 is the terminology standard for petrographic analysis of bituminous coal and anthracite. Its subject is the technical language used around macerals, microlithotypes, and the determination of vitrinite reflectance. In practice, this gives a common vocabulary for describing the microscopic makeup and optical properties of coal.

Core concepts in coal petrography

Petrographic analysis looks beyond bulk composition and examines coal at the microscopic level. Macerals are the principal organic constituents used to classify coal texture and composition. Microlithotypes describe how those constituents occur together in a polished or thin-section view. Vitrinite reflectance is an optical measurement closely associated with coal rank, providing a widely used indicator of maturity in bituminous coal and anthracite.

What this terminology standard supports

The scope covers definitions connected with maceral and microlithotype analyses carried out in white light, as well as the determination of vitrinite reflectance. So, this document functions as a terminology base rather than a test method in itself. It helps ensure that laboratory reports, technical specifications, and professional discussions use the same terms with the same meaning.

For users working with higher-rank solid fuels, this standard is useful because it aligns the descriptive terms used to interpret coal structure, optical response, and petrographic appearance. It focuses on the concepts that frame the analysis, not on the sample itself, which makes it a reference point for consistent communication in coal petrography.

• Maceral: a microscopic organic component of coal
• Microlithotype: a microscopic unit made up of associated macerals
• Vitrinite reflectance: an optical indicator used to assess coal rank
• White light analysis: the illumination context used for petrographic observation