Identify the measured dose
State whether the trial reports active mass, commercial-product mass or solution volume. Keep dry-solids or water-flow units explicit and synchronize the process measurements.
If consumption is already as-supplied kilograms per treatment unit, multiply directly by price per commercial kilogram. Dividing by active fraction again would double-correct the quantity.
Use the supplier's documented active basis
Ask how active polymer is defined and how it relates to dry matter or nonvolatile content. Do not automatically count all powder or emulsion solids as active polymer.
When starting from a genuine active dose, divide by the declared active mass fraction to obtain commercial consumption. Liquid volume additionally requires the relevant density, while prepared stock needs its own concentration convention.
Keep the accepted endpoint fixed
Compare grades at the required capture, clarity, cake or underflow condition and throughput. Equal active dose can be a screening comparison, not proof of equivalent economic value.
Repeat useful conditions on representative feed and disclose process differences. A precise cost calculation cannot repair a trial where one supplier was tested on easier sludge or a different coagulant program.
Align the delivery scope
Record quantity, currency, packaging, named place, included freight or handling and validity. Treat an unqualified code's price as provisional rather than a proven substitute cost.
The factory quotation guide separates technical equivalence from commercial terms. Add preparation and downstream costs only where measured or explicitly costed.
A hypothetical normalization check
For arithmetic illustration only, a 2 kg active dose at a hypothetical active fraction of 0.50 corresponds to 4 kg commercial product. A recorded 4 kg commercial dose must not be divided by 0.50 again. These values are not grade specifications or treatment recommendations.
Keep the original weighing and concentration records alongside the spreadsheet. Send them through the factory price enquiry with the approved code, process endpoint and destination so the offer answers a defined treatment and delivery requirement.
Cost comparison evidence
| Checkpoint | Evidence to retain | Decision boundary |
|---|---|---|
| Original dose | Retain whether the trial quantity is active mass, commercial mass or stock volume, with synchronized process loading. | Do not correct an already commercial-product dose a second time for the active fraction. |
| Product basis | Keep the supplier's active definition and the actual density or stock convention needed for conversions. | Dry matter, neat-product volume and active polymer cannot be substituted for one another without supporting definitions. |
| Accepted value | Retain process quality, throughput, delivered scope and measured preparation or disposal consequences. | A lower price per tonne or equal active mass does not prove a lower cost of an accepted treatment result. |