Example of a graphical representation of interlaboratory comparison results

Example of a graphical representation of interlaboratory comparison results

Source: BAM

Since 2004, the Bundesanstalt für Materialforschung und -prüfung (BAM) has regularly carried out interlaboratory tests for particle size determination on ultra-fine powders using laser diffraction analysis in accordance with ISO 13320.


The purpose of the programme is proficiency testing for the participating laboratories according to DIN EN ISO/IEC 17043:2010.


Generally, all users of devices for particle size determination using laser diffraction methods can participate if they send in the declaration of participation and pay a participation fee following the receipt of the results report and invoice (laser diffraction methods independent of device type/manufacturer; MIE calculation is essential).
A minimum number of 12 participants is required for the interlaboratory test to go ahead.


The organiser of the interlaboratory test selects three ceramic powders which have particle size distributions graded approximately in the range between 0.5 and 50 μm. All three samples must be dispersed wet and measured as a suspension (dispersing agent tetrasodium pyrophosphate/Na4P2O7). The evaluation is to be carried out using the MIE calculation. The required optical parameters are supplied.

Test schedule

The samples will be shipped to the laboratories. Each test item shall be tested in six rounds, meaning a total of 18 measurements are required. Along with the material, participants will receive standard operating procedures for the preparation and measurement of the sample based on ISO 13320. Results will be submitted electronically using a form provided by the organiser. The deadline for this is one month following the receipt of the samples.


The data received will be compiled by the organiser anonymously and evaluated in accordance with DIN ISO 13528 using the ProLab software.


The cost for an interlaboratory test including evaluation, final report and a graded certificate of participation amounts to €530 plus VAT.