ISO 13909-2:2025

Overview

ISO 13909-2:2025 - "Coal and coke - Mechanical sampling - Part 2: Sampling of coal from moving streams" provides standardized procedures and requirements for the design, establishment and operation of mechanical samplers used to collect representative samples of coal conveyed in continuous (moving) streams. This third edition updates the scope to focus on coal, revises calculations for sub-lots and increments, and aligns terminology with the ISO 13909 series. It does not cover sampling from stationary lots (see ISO 13909-3).

Key topics and technical requirements

The standard organizes requirements that ensure representative, reproducible sampling and covers:

• Establishing a sampling scheme

  • Defining quality parameters, lots and sub-lots
  • Choosing time-basis or mass-basis sampling
  • Determining sampling intervals and increment masses
  • Assessing variability, precision and bias

• Precision and variance

  • Guidance on required precision, total variance, primary increment variance, and preparation/testing variance
  • Procedures for calculating number of sub-lots and increments to meet precision targets

• Methods of sampling

  • Time-basis sampling and mass-basis sampling
  • Stratified random sampling (time- and mass-basis variants)
  • Reference sampling techniques

• Design of mechanical samplers

  • General design principles, safety, location and information requirements
  • Specific sampler types: falling-stream and cross-belt samplers (operation and design considerations)
  • Cutter velocity, increment mass, maintenance and provisions for checking precision and bias

• Sample handling, storage and preparation

  • Requirements for sample storage, preparation of test samples (see ISO 13909-4), and minimizing bias

• Verification and testing

  • Procedures for checking precision and bias; Annex A addresses evaluation of equipment for mass-basis sampling

Practical applications

ISO 13909-2:2025 is practical for:

• Designing and commissioning mechanical sampling systems for conveyors, chutes or other continuous coal streams
• Developing sampling plans to meet contract or regulatory quality requirements
• Supporting quality control, process monitoring and commercial trade (e.g., calorific value, moisture, ash)
• Establishing maintenance, verification and bias-checking routines to ensure representative sampling over time

Who should use this standard

• Coal producers and mine operators
• Sampling system designers and equipment manufacturers
• Quality assurance and laboratory managers
• Inspectors, auditors and trading partners involved in coal contracts
• Regulatory bodies and consultants overseeing sampling compliance

Related standards

• ISO 13909-1 (General introduction)
• ISO 13909-3 (Stationary lots)
• ISO 13909-4 (Preparation of test samples)
• ISO 13909-7 (Methods for determining precision)
• ISO 13909-8 (Methods for testing bias)
• ISO 21398 (Guidance to inspection of mechanical sampling systems)

For implementation, obtain the full ISO 13909-2:2025 text from ISO or your national standards body to ensure compliance with all technical details.