Overview
ISO 3085:2019 - "Iron ores - Experimental methods for checking the precision of sampling, sample preparation and measurement" - defines experimental procedures to evaluate how precise your iron‑ore sampling system and downstream laboratory processes are. The standard is intended for use alongside ISO 3082 (sampling and sample preparation) and the relevant ISO measurement standards (chemical analysis, moisture, size), and it can be applied to check sampling, sample preparation and measurement either together or separately.
Key topics and requirements
- Purpose: Estimate the precision of the whole sampling-to-measurement chain or of individual stages (sampling, preparation, measurement).
- Experimental design: Preferably use more than 20 lots (minimum 10 if impracticable) and, where possible, take twice the routine number of increments so two gross samples can be formed by alternating increments.
- Sampling methods: Supports systematic sampling and stratified sampling depending on how increments are taken (see ISO 3082).
- Sample preparation & measurement: Follow ISO 3082 procedures for sample preparation; measurements must follow the relevant ISO chemical, moisture and size analysis standards. Repeated determinations over several days are recommended for chemical assays to maintain independence.
- Data analysis: Uses the mean square difference between assay pairs to estimate precision (a key change in the 2019 edition). The standard provides methods (Method 1, 2, 3) for analyzing experimental data and interpreting results.
- Actions when precision is insufficient: The standard outlines remedial actions such as checking for changes in quality variation, increasing the number or mass of increments, and reviewing sample preparation and measurement procedures.
- Record keeping and reporting: Detailed, standardized records and a formal test report are required for traceability and future comparisons.
Practical applications and users
ISO 3085:2019 is practical for organizations that need robust quality control of iron‑ore consignments and laboratory results:
- Mining companies and mine QC teams
- Sampling technicians and metallurgical engineers
- Assay and analytical laboratories performing iron‑ore testing
- Quality managers, contract inspectors and commodity traders validating sampling systems
- Equipment and sampling-system suppliers assessing system performance
Using ISO 3085 helps demonstrate that sampling systems meet precision criteria (as referenced in ISO 3082), supports dispute resolution on cargo quality, and guides improvements to sampling and laboratory practice.
Related standards
- ISO 3082:2017 - Iron ores - Sampling and sample preparation procedures
- ISO 3084 - Iron ores - Experimental methods for evaluation of quality variation
- ISO 11323 - Vocabulary for iron ore and DRI
Keywords: ISO 3085:2019, iron ores, sampling precision, sample preparation, measurement precision, ISO 3082, systematic sampling, stratified sampling, mean square difference, QC for iron ore.
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