DLS Intensity and Number Distributions: Do Not Swap the Axis Label

The key distinction

Malvern Panalytical discusses these representations and the assumptions involved in converting between them. A buyer should obtain the original report and ask which distribution supports the proposed specification. A chart dominated by one population on an intensity basis should not be relabelled as the percentage of particles without a justified analysis.

Practical checks

1. Record the distribution basis alongside every copied chart or summary value.
2. Ask the laboratory about assumptions used in any conversion.
3. Keep the original data presentation available when preparing a supplier comparison or technical claim.

Example

Illustrative example: a presentation describes a peak as the size of most particles, although the source chart is intensity weighted. That wording may overstate what the chart shows. A more accurate summary identifies the reported distribution and leaves population claims to an analysis that supports them.

Scope and limits

Do not select whichever representation makes a sample look most uniform. The appropriate representation depends on the question and the measurement limitations. A tidy chart is not evidence that a finished ceramic coating will be easier to apply or more durable in customer use.

Related guidance

• Coating Inspection Values: Do Not Round Before the Final Decision
• Missing Follow-Up Visits in Coating Trials: Do Not Count Unknown Results as Passes
• Scratch-Test Tip Geometry: A Load Number Is Not Enough
• Viscosity Inputs in DLS: A Sample Setting Can Change the Size Result

Technical references: Malvern Panalytical: Zetasizer terminology. These sources describe their stated methods or products; they do not certify NANOLAB products or establish compatibility with an unlisted surface.

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.