Overview
EN ISO 14720-1:2026 (Testing of ceramic materials - Determination of sulfur in non-oxidic ceramic raw materials and ceramic materials - Part 1: Infrared measurement methods) is a European and international standard that specifies procedures for quantifying sulfur in non-oxidic ceramic raw materials and ceramic products. This document is a joint publication by CEN and ISO, developed under technical committees for refractories and ceramic materials. Its scope covers a variety of materials including silicon carbides, silicon nitrides, graphites, carbon blacks, cokes, and related carbon powders. The standard primarily applies to sulfur mass fractions ranging from 0.005% to 2%, but can also be extended to higher concentrations after proper verification.
Key Topics
- Infrared Measurement Methods: The standard details procedures using infrared (IR)-and, where relevant, ultraviolet (UV)-absorption measurement following high-temperature combustion under oxygen. This analytical method ensures reliable quantification of sulfur content in non-oxidic ceramics.
- Sample Preparation: Emphasizes representative sampling, sample drying (at 110°C to constant mass), particle size reduction (≤ 160 µm), and appropriate storage to ensure accuracy and reproducibility.
- Combustion Process: Uses combustion accelerators (typically tungsten, tin, or iron granules) to enhance the release of sulfur as SO₂, which is then measured via IR or UV absorption for quantification.
- Calibration and Reference Materials: Highlights the necessity of calibration using suitable certified reference materials (CRMs) and robust blank value determination.
- Precision and Reporting: Specifies requirements for repeatability, reproducibility, and comprehensive test reporting, including uncertainty quantification when required.
Applications
The procedures outlined in EN ISO 14720-1:2026 provide essential tools for:
- Ceramic Raw Material Quality Control: Reliable sulfur determination helps manufacturers validate product properties and ensure conformance to technical specifications for materials such as silicon carbide and graphite, which are widely used in high-performance ceramics and refractories.
- Refractory and Advanced Ceramic Manufacturing: Monitoring sulfur in raw materials prevents defects and optimizes thermomechanical performance, crucial for industries such as steel, glass, and energy sectors using non-oxidic refractories.
- Research and Development: Laboratories engaged in material research use these standardized methods to benchmark new materials, validate alternative test methods, or develop improved production processes.
- Powder and Granular Material Testing: The standard is applicable beyond ceramics, extending-with verification-to other non-metallic materials such as silicon dioxide, aiding broader material science and chemical industry applications.
- Accredited Laboratory Services: Ensures analytical laboratories can offer sulfur determination services that are recognized internationally, supporting certification and regulatory compliance.
Related Standards
Several key standards are referenced or complement the implementation of EN ISO 14720-1:2026:
- ISO 8656-1: Sampling of raw materials and unshaped refractory products.
- ISO 5725-2, ISO 5725-4: Guidelines on measurement accuracy, repeatability, and reproducibility.
- ISO/IEC Guide 98-3 (GUM: 1995): Guidance on expressing uncertainty in measurement.
- ISO 21748: Instructions for using precision data in uncertainty evaluation.
- EURACHEM and EUROLAB Guides: Provide additional methodologies and best practices for uncertainty assessment and method validation.
- Certified Reference Materials Databases (e.g., COMAR): Comprehensive resources for suitable calibration materials for the relevant measurement range.
Implementing EN ISO 14720-1:2026 assures reliable, precise sulfur measurement in non-oxidic ceramics and related materials, supporting product quality, innovation, and regulatory compliance across the ceramics supply chain.