ISO/TS 24498:2022 PDF

Overview - ISO/TS 24498:2022 (Paper, board and pulps)

ISO/TS 24498:2022 provides practical guidelines for estimating the measurement uncertainty of test methods used in the pulp, paper and board sector. The Technical Specification covers tests for lignins and kraft liquors, pulps, paper, board, cellulosic nanomaterials, and related products including those with recycled content. It describes how to run and evaluate interlaboratory comparisons (precision experiments) to produce reproducible precision statements for ISO test methods.

Key topics and requirements

• Scope and purpose: Methodology to estimate the random component of uncertainty (repeatability and reproducibility) for test methods used in ISO/TC 6.
• Preferred procedure: Interlaboratory studies organized by the working group developing the test method. If not possible, use data from comparative testing services or bibliographic sources.
• Laboratory qualification:
  • Laboratories should be competent and properly equipped (ISO/IEC 17025 or equivalent recommended).
  • Recommended minimum of eight participating laboratories; never fewer than five for a valid interlaboratory comparison.
• Sample selection and handling:
  • Materials should cover the expected range of values and be as uniform and stable as possible.
  • Special care for materials sensitive to relative humidity and temperature (paper, board, cellulosic nanomaterials).
  • Guidance on identification, packaging, randomization and sample distribution to minimize heterogeneity effects.
• Testing and analysis:
  • Procedures for data collection, statistical calculations, consistency evaluation, and handling of outliers.
  • Emphasis on adequate replication (many standardized methods use 10 or more measurements) to improve precision.
• Reporting and archiving: Requirements for the precision statement, report content, and archiving of raw data for re-evaluation.

Practical applications and users

ISO/TS 24498 is essential for:

• Standards developers and technical committees preparing or revising ISO test methods.
• Testing laboratories seeking to validate method performance and support precision statements.
• Manufacturers, quality assurance teams and certification bodies that require reliable uncertainty estimates for conformity assessment.
• Proficiency testing providers and collaborative testing services using comparative data for pulp and paper analyses. Common uses include preparing precision statements, evaluating new or revised test methods, demonstrating conformance to specifications, and supporting research comparing materials or processes.

Related standards (select)

• ISO 5725 series - general methods for the determination of repeatability and reproducibility.
• ISO 187 - standard atmosphere for conditioning and testing of paper, board and pulps.
• ISO/IEC 17025 - laboratory competence (recommended for participating labs).

Keywords: ISO/TS 24498:2022, interlaboratory comparisons, uncertainty estimation, repeatability, reproducibility, paper testing, pulp, cellulosic nanomaterials, precision statement.