ISO 14720-1:2026

Overview

ISO 14720-1:2026 specifies a standardized infrared measurement method for determining sulfur content in non-oxidic ceramic raw materials and ceramic products. Typical materials covered by this method include silicon carbides, silicon nitrides, graphites, carbon blacks, cokes, and carbon powders. The standard is also applicable, under certain conditions, to other non-metallic powdered and granular materials, such as silicon dioxide. It is designed for determining sulfur mass fractions in the range of 0.005% to 2%, with the possibility for higher concentrations if appropriately verified.

This international standard supports accurate sulfur analysis, which is critical for quality control and performance in ceramic manufacturing and other industries using high-performance materials.

Key Topics

• Infrared Measurement Methods: Utilizes an induction furnace and an infrared absorption cell (or, alternatively, an ultraviolet absorption cell) to detect sulfur released as sulfur dioxide gas during sample combustion.
• Applicable Materials: Designed for non-oxidic ceramics and raw materials in powder or granular form, specifically silicon compound ceramics and carbon-based materials.
• Concentration Range: Valid for materials with sulfur contents from as low as 0.005% up to 2%; may apply to higher concentrations upon verification.
• Sample Preparation:
  • Requires samples to be dried, crushed to ≤160 μm particle size, and homogenized for representativity.
  • Pre-cleaned ceramic crucibles and calibration with certified reference materials are essential for accuracy.
• Calibration and Validation: Calibration samples (preferably certified reference materials) should closely match the sample matrix for reliable results. Measurement accuracy is assured through regular verification and the use of suitable reference materials.
• Precision and Reporting:
  • Specifies guidelines for repeatability and reproducibility based on inter-laboratory studies.
  • Requires clear documentation in test reports, including results, methods, calibration information, uncertainties, and sample identification.

Applications

• Ceramic Manufacturing: Ensures raw materials and finished products meet strict sulfur specifications, which can impact material performance, especially at high temperatures.
• Quality Assurance: Reliable sulfur determination supports compliance with product specifications, industry regulations, and customer requirements.
• Research and Development: Useful for materials scientists and researchers developing or characterizing advanced ceramic materials or studying the influence of sulfur on ceramic properties.
• Supplier Evaluation: Allows buyers and manufacturers to validate the purity and suitability of sourced raw materials.
• Other Industries: Applicable to sectors requiring low-sulfur content in non-metallic powdered materials, such as refractories, electronics, and specialty chemical producers.

Related Standards

• ISO 8656-1: Procedures for sampling refractory materials and raw ceramics.
• ISO 5725-2: Guidelines on measurement method accuracy, repeatability, and reproducibility.
• ISO/IEC Guide 98-3 (GUM): Standards for expressing measurement uncertainty.
• ISO 21748: Guidance on using repeatability, reproducibility, and trueness in uncertainty evaluation.
• EURACHEM/CITAC Guides: Recommendations for analytical method validation and quantifying measurement uncertainty.

For organizations aiming for excellence in materials testing and ceramic production, ISO 14720-1:2026 provides a robust framework for precise sulfur determination using infrared analysis methods, ensuring product quality and industry compliance.