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Reports & Downloads

Test notes written by our engineers, plus the documents most often asked for at quotation stage. Everything here is free and none of it needs a form filling in.

How To Read An Accredited Report

Every accredited report we issue contains the same eleven elements, and knowing what they are makes it much easier to compare two laboratories' results — or to spot when the figure in a sales brochure did not come from a report at all.

  1. Report number and issue date. A revised report carries a new number; superseded reports are withdrawn, not quietly edited.
  2. Client and specimen identification. Including who supplied the specimen and who built it into the aperture.
  3. Test standard and edition. Standards get revised; the edition matters.
  4. Specimen description. Full construction, layer by layer, with densities and thicknesses as measured by us — not as stated on the delivery note.
  5. Mounting or installation condition. The single most influential variable in absorption testing.
  6. Environmental conditions. Temperature and relative humidity during measurement.
  7. Results per third-octave band. In a table, not only as a graph.
  8. Single-number rating and derivation. Which standard the rating comes from.
  9. Measurement uncertainty. Stated, not implied.
  10. Accreditation statement. Which parts of the report the accreditation covers.
  11. Two signatures. The engineer who measured and the engineer who checked.

If a figure you are being shown cannot be traced to a document with all eleven, it is a marketing number. That does not make it wrong — but it is not evidence.

Test Notes

Test Note 14 — Mounting condition and the absorption curve

The same 40 mm mineral wool panel measured in three mounting conditions, with the three curves overlaid. Explains why data sheets should always state the mounting type, and what to do when they do not.

Test Note 13 — Sound power and sound pressure are not the same quantity

Why a tender that asks for "maximum 55 dB(A) sound power at three metres" is asking for something that does not exist, and how to write the requirement so that it can actually be verified.

Test Note 12 — Flanking transmission, or why the wall got worse when it was built

A laboratory Rw of 52 dB routinely becomes 43 dB on site. Where the other nine decibels go, with measurements from three buildings.

Test Note 11 — The uncertainty term nobody quotes

What K means in a declared noise emission value, how it is derived, and why omitting it makes a declaration non-compliant with EN ISO 4871.