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Reading Test Reports: The Conditions Section Is the Report

Part of the Testing & Analysis: The Complete Guide — this article is one of the detailed pages in the guide.

Direct answer: A test report's headline number — conversion, K value, capacity — means nothing without its conditions: gas composition, temperature, space velocity, sample history and test standard. The professional habit is to read the conditions section first and treat every number as a pair: value plus context. Reports without stated conditions are marketing material.

The mandatory context list

Any performance number needs, at minimum:

  • Gas composition — species and concentrations, including H₂O and O₂; for SCR: NOx, NH₃, SO₂, and the NO₂/NOx ratio.
  • Temperature — measured where, and held how steadily.
  • Flow / space velocity — gas flow per catalyst volume or surface.
  • Sample description — fresh, aged, regenerated; core, coupon or full module; from which layer and position.
  • Test standard — which method was followed (ISO, GB, ASTM, in-house with stated procedure).

Numbers that mislead without context

  • "99% conversion" — at what inlet concentration? Against what species mix? High conversion at high inlet says more than the same number at trace inlet.
  • "T90 = 170°C" — in dry clean gas or humid sulfur-bearing gas? The difference can be 50°C.
  • "Iodine number 1,000" — a quality indicator, not a performance prediction for your specific VOC.
  • "K = 42 m/h" — the industry reference point; the number alone cannot be compared across suppliers unless conditions match.

How to compare two reports

  1. Align the conditions first — if temperatures or compositions differ, normalize or discard the comparison.
  2. Check sample age and history — an aged sample's K is not comparable to a fresh sample's.
  3. Verify the calculation — conversion, AV and K must be internally consistent (K = −AV × ln(1−η)).
  4. Ask for raw data — a single summary number hides scatter; raw curves show stability.

Red flags in reports

  • No gas composition stated.
  • Test temperature outside your application range.
  • "Typical values" without test date, batch or traceability.
  • Sample described only as "catalyst" — which product, which batch, which history?
  • Conversion quoted without inlet concentration.

Manufacturer perspective

We publish conditions alongside every performance claim and provide raw data on request. When customers bring competitor reports, we compare them on the conditions first — that is where claims usually collapse.

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