The anatomy of a usable entry
Every measured entry should contain six parts. Missing any one of them downgrades the entry from a specification to a headline:
- Property — what is being described (ash, moisture, fixed carbon, size…).
- Value — the number, with a direction (≤, ≥, ±) rather than a bare figure.
- Unit — %, mm, g, kcal/kg, minutes, as appropriate.
- Method — the standard or procedure that produced the number.
- Basis — dry or as-received.
- Batch and laboratory — which batch, tested by whom, and when.
Field by field
Size and tolerance
"25 mm" is a nominal target, not a measurement. A usable size entry states the nominal dimension and the tolerance (for example ±0.5 mm), plus how conformance is checked. Without the tolerance, two suppliers quoting "25 mm" may ship noticeably different products — see size tolerance.
Moisture
Moisture should carry a basis (usually as-received) and a drying condition. Because charcoal is hygroscopic, a figure measured at origin may not describe the load as delivered. Ask when and how the sample was taken — see moisture.
Ash
Ash should carry the method and basis. Different methods ash at different temperatures, so ash figures are only comparable within a method family — see ash content.
Fixed carbon
Fixed carbon is calculated by difference, so check that it reconciles with the reported moisture, volatile matter and ash on the same basis. If it does not, the sheet is internally inconsistent — see fixed carbon.
Performance claims (burn time, ignition time, odour)
These have no universal standard. A burn-time figure is only meaningful with its test conditions attached — fuel mass, apparatus, ignition method, airflow and endpoint. Treat a bare "60 minutes" as a scenario, not a property — see burning time and ignition time.
What a missing field signals
A missing method or basis is the most common red flag. It is usually not malice — it is often a marketing datasheet that was never written to be enforced. The remedy is the same in every case: ask for the raw report, and confirm the laboratory is independent of the supplier.