Overview
ISO 13909-2:2016 - Hard coal and coke: Mechanical sampling - Part 2: Coal - Sampling from moving streams specifies procedures and requirements for designing and establishing mechanical samplers used to take representative coal samples from moving streams (e.g., conveyors). The standard describes accepted sampling methods, requirements for sampler design, and procedures to control precision and bias. It expressly excludes sampling from stationary lots (see ISO 13909‑3).
Key topics and technical requirements
- Establishing a sampling scheme: defining lot/sub-lot boundaries, quality parameters, required precision, and the number of increments and sub-lots needed to meet precision targets.
- Sampling bases: guidance on choosing between time-basis sampling (fixed time intervals) and mass-basis sampling (intervals by mass flow), including operational trade-offs and equipment needs (e.g., belt weighers for mass-basis).
- Methods of sampling: descriptions of primary increment collection methods - time-basis, mass-basis, stratified random sampling, and reference sampling - with rules for sampling intervals and increment masses.
- Design of mechanical samplers: requirements covering safety, location, maintenance, checking for bias and precision, and specific designs such as falling-stream samplers and cross-belt samplers (including cutter operation and velocity considerations).
- Sample mass and size: procedures for determining minimum sample mass, average increment mass, and size analysis needed to ensure representativity.
- Quality control: evaluation of precision (variance components: primary increment variance, preparation/testing variance), bias minimization, verification procedures, and provisions for checking sampler performance. Annex A gives evaluation guidance for mass-basis equipment.
- Handling and preparation: requirements for handling, storage and preparation of test samples to avoid contamination or segregation prior to analysis.
Practical applications and users
ISO 13909-2:2016 is intended for organizations involved in coal production, handling, trading and testing, including:
- Coal mine operators and bulk material handlers designing sampling systems for conveyors and transfer points.
- Equipment manufacturers and engineers specifying or building mechanical samplers (cross-belt or falling-stream designs).
- Quality control and analytical laboratories that rely on representative samples for testing (calorific value, moisture, ash, contaminants).
- Inspectors, auditors, and commercial parties (buyers/sellers) requiring standardized, verifiable sampling practice to reduce disputes.
- Regulators and certification bodies setting compliance or inspection requirements.
Related standards
Keywords: ISO 13909-2:2016, mechanical sampling, hard coal, coal sampling from moving streams, time-basis sampling, mass-basis sampling, cross-belt samplers, sampling precision, sampling bias.
Open preview (PDF)Hard coal and coke — Mechanical sampling — Part 2: Coal — Sampling from moving streams
