Three measurements, three different questions
| Measurement | Procurement interpretation |
|---|---|
| Blaine | An air-permeability fineness result expressed as specific surface, commonly in m²/kg or cm²/g. Ask for method, sample identity and unit. |
| Sieve residue | The retained fraction for a named sieve opening and test method. A residue percentage without the opening and method is incomplete. |
| Laser-diffraction PSD | A size distribution derived from light scattering and an optical model. Request the distribution basis and method settings, not just a single diameter. |
NIST’s SRM 114r publication reports Blaine, 45-µm residue and light-scattering PSD separately, with different value-status descriptions. ISO 13320 explains that laser-diffraction results for non-spherical particles differ from measurements based on other principles.
Unit conversion is not method conversion
A specific-surface result can be expressed in another compatible unit: 1 m²/kg = 10 cm²/g. Thus 350 m²/kg equals 3,500 cm²/g. This is an illustrative unit conversion, not a measured result for any product or cement.
It does not convert Blaine into mesh, sieve residue or d50. A mesh designation identifies a sieve system; it is not a complete distribution. A d50 result needs its stated basis and measurement method. Do not use an unexplained conversion table to decide that one additive produced equivalent cement quality.
If a supplier calculates a relationship from its own plant data, request the underlying paired measurements, material range, method and uncertainty. Keep the relationship scoped to that data instead of treating it as universal.
Ask for comparable samples before comparing suppliers
Request sample IDs, collection times, cement composition, additive grade/lot and confirmed dose basis. Match baseline and candidate process records to those samples. A laboratory result from a different cement blend or a different operating interval may not answer the purchasing question.
For PSD, ask the laboratory to identify preparation and dispersion conditions, instrument, model, reported basis and repeatability information. For Blaine and residue, ask for the applicable method and calibration record. The responsible laboratory should establish appropriate methods; this page does not reproduce a standard test procedure.
Maintain consistent units and methods in the comparison. Where they differ, show the difference in the report rather than merging all results into a single “fineness improvement” percentage.
Separate fineness evidence from a performance promise
A fineness result alone is not proof of strength, water demand or setting performance. Ask for those agreed quality results from traceable samples if they matter to acceptance. Likewise, a throughput or energy claim should remain conditional on meeting the agreed cement-quality requirements.
Use the report checklist to expose changed conditions and missing data. The mill-trial protocol remains the method-planning page. This guide only helps the buyer understand the reported measurements.
What to include in the enquiry
Send cement designation and composition, mill type, baseline fineness units/methods, available residue and PSD records, relevant strength or other quality limits, target improvement and destination. State which measurements are unavailable. A missing PSD is an evidence gap to discuss, not permission to estimate it from Blaine.
Request a proposed grade, current documents, an evaluation plan and a quotation with net mass, packaging, lead time and validity. Do not accept a claim of guaranteed strength or interchangeable test methods without directly applicable evidence. Review document availability in the quality library.
Prepare your enquiry
Cement and mill identity, baseline fineness methods/units, quality limits, target, estimated consumption and destination.
Request the exact grade, current document availability, sample terms, net package mass, quotation validity and delivery terms. Suitability and performance remain subject to applicable documents and agreed evaluation.
Sources and scope
- NIST SP 260-226 (2022): distinct fineness measurements
- ISO 13320:2020: laser-diffraction scope and limitations
Sources provide general background or measurement scope. The buyer checklists are our editorial recommendations, not reproduced test standards or proof of product performance. Reviewed 9 October 2026.