ISO 13909-3:2025

Overview

ISO 13909-3:2025 - "Coal and coke - Mechanical sampling - Part 3: Sampling of coal from stationary lots" specifies procedures for mechanical sampling of coal from stationary lots (wagons, barges, ships, stockpiles). It applies when sampling during loading or discharge (see ISO 13909-2) is not possible. The standard focuses on designing sampling schemes, taking and distributing increments, handling and storage, and ensuring results suitable for moisture determination and general physical/chemical analysis. Methods are limited to those for which bias can be tested.

Keywords: ISO 13909-3:2025, mechanical sampling coal, sampling of coal from stationary lots, wagons barges ships stockpiles, sampling scheme, sampling bias, moisture determination, primary increment.

Key topics and technical requirements

• Scope and applicability: Mechanical sampling from stationary lots to produce test samples for moisture and general analysis; restricted to methods amenable to bias testing.
• Designing a sampling scheme: Stepwise procedure including defining quality parameters, lot definition, required precision, increment combination method, assumed variability, number of sub-lots and increments, sampling interval (tonnes), nominal top size, and minimum increment mass.
• Precision and variance: Guidance on required precision, estimating total variance (sampling + preparation/testing), assumptions for unknown coals, and when to use replicate sampling to measure precision.
• Bias control: Requirement to check for sampling bias (see ISO 13909-8) and limit causes that alter measured parameters (e.g., restricting increment mass and standing time for moisture samples).
• Sampling methods: Practical methods for wagons, barges, ships and stockpiles, including number and distribution of increments, taking increments, and random selection practices.
• Equipment and handling: Reference to mechanical auger equipment, sample handling, storage and sample preparation practices (detailed in ISO 13909-4).
• Verification and testing: Procedures to verify precision and bias, and to re-evaluate schemes if variability changes.

Practical applications and users

Who uses ISO 13909-3:2025:

• Coal producers and mine operators designing commercial sampling programs
• Port and terminal operators sampling wagon, barge and ship consignments
• Quality control and analytical laboratories preparing test samples for moisture and composition analysis
• Traders, buyers and regulators requiring defensible, bias-testable sampling results
• Engineers and consultants developing sampling plans for stockpiles or stationary consignments

Practical benefits:

• Consistent, repeatable sampling schemes for contractual quality control
• Transparent methods to estimate precision and minimize bias
• Guidance for selecting increment mass, sub-lots and sampling intervals to meet analytical needs

Related standards

• ISO 13909-1 (General introduction)
• ISO 13909-2 (Sampling from moving streams)
• ISO 13909-4 (Preparation of test samples)
• ISO 13909-7 (Methods for determining precision)
• ISO 13909-8 (Methods of testing for bias)

For implementation, users should consult ISO 13909-4 for sample preparation and ISO 13909-7/8 for precision and bias testing.