Overview
EN ISO 17829:2025 - Solid biofuels: Determination of length and diameter of pellets specifies standardized methods to measure pellet diameter and length, including procedures to determine fractions of pellets by size (for example pellets > 40 mm and particles < 10 mm) and to calculate average pellet length. Published by CEN as the European adoption of ISO 17829:2025, this edition supersedes the 2015 version and extends the scope to include detailed fraction analysis and updated measurement methods.
Key topics and technical requirements
- Scope and purpose: Defines how to determine pellet diameter class and pellet length parameters that influence bulk density, handling and combustion performance.
- Measurement principles: Describes the principle for diameter classification (linked to ISO 17225-2) and for length measurement.
- Apparatus and sample preparation: Specifies required equipment and sample preparation rules to ensure representative test portions.
- Length measurement options:
- Option A: Using a measuring block/device designed for pellet length.
- Option B: Using callipers to measure individual pellets.
- Fraction determination: Methods to quantify shares of pellets in specified length ranges (including coarse fines and very short particles < 10 mm) and procedures to report the proportion of pellets exceeding specified maximum lengths (e.g., > 40 mm).
- Calculations and reporting: Rules for calculating diameter class, shares of specified fractions, average pellet length, and reporting test results.
- Performance characteristics and annexes: Includes informative annexes with device designs, comparative studies between methods, and an example construction plan for a measuring block.
Practical applications and users
This standard is practical and widely used for quality control, compliance and procurement across the solid biofuels value chain:
- Pellet manufacturers: to control production, optimize pelletizing parameters and demonstrate compliance with size specifications.
- Fuel suppliers and traders: to verify delivered product meets contractual and fuel-class requirements.
- Testing laboratories and certification bodies: to perform accredited tests and produce reproducible reports.
- Boiler and burner manufacturers / plant operators: to assess fuel compatibility with feeders, conveyors, and combustion systems.
- Regulators and standards committees: for conformity assessment and alignment with ISO 17225 fuel classes.
Related standards
EN ISO 17829:2025 references and aligns with other key solid biofuel standards, including:
- ISO 17225-1 / -2 / -6 / -8 (fuel specifications and pellet classes)
- ISO 16559 (vocabulary)
- ISO 14780 (sample preparation)
- ISO 5370 (fines content)
- ISO 18135 / ISO 21945 (sampling)
Use EN ISO 17829:2025 when precise, standardized measurement of pellet dimensions is required for product specification, quality assurance, or compliance with fuel classification systems.