Catalogues and registration

An interlaboratory test to evaluate the performance of participants is defined as a proficiency test. The objective of the proficiency tests is to give participants the opportunity to prove and improve their testing competences. Our proficiency testing program covers a wide range of tests and analyses. The focus is on different plastic materials, plastic products and plastics processing. To register, you can use our catalogue, which contains our complete range of proficiency tests. You will find the catalogue continuously at the top right-hand corner. Our offer contains a wide range of proficiency tests according to ISO/IEC 17043:2010. The exact scope can be found in the accreditation certificate. The statistical evaluation is according to ISO 13528:2015-08.

As a clear distinctive feature of our international activities in the field of interlaboratory comparisons, the Kunststoff-Institut Lüdenscheid offers proficiency tests under the brand name “Deutsches Institut für Ringversuche”.



Kunststoff-Institut Lüdenscheid (Interlaboratory Testing)




Participation in our international proficiency test series is not limited by specific guidelines. Knowledge and facilities for the implementation of the procedure are sufficient for participation. Well-structured processes throughout the entire cycle of the round robin test are very important to us. Well-organised information will reduce your workload. The round robin testing procedure is characterized by four phases. All dates are announced before the proficiency test starts. Essential information will be available via the  online portal. Thus, you can completely concentrate on your tasks.


1. Registration period

  • We provide information about our PT program
  • Registration via our Online Catalogue
  • In case of questions do not hesitate to contact us
  • The registration phase ends with the registration deadline. All dates are listed in the catalogue for each product group
2. Preparatory phase

  • Planning and preparation of your examinations or tests
  • You will find further instructions on how to carry out your test in the online portal
  • The preparation phase ends with the date of the sample shipment. All dates are listed in the catalogue for each product group
3. Testing phase

  • Conduction of tests which will be assessed
  • Result submission via the online portal
  • The testing phase ends with the deadline for the result submission. By this date you have to enter your results in the online portal, confirm them and finish the process.
4. Evaluation phase

  • Statistical data analysis
  • Preparation of reports and certificates
  • Shipping of reports and certificates




In addition to excellent sample quality, we consider the application of appropriate statistical methods, which not only meet the objective of the interlaboratory comparison but can also be understood intuitively by the participants, to be one of the fundamental principles of our interlaboratory comparisons. In the field of statistics, you benefit from our cooperation with QuoData GmbH, one of the world’s most renowned specialists in statistics for interlaboratory comparisons. This ensures that modern methods are used that are conform to ISO 17043 and ISO 13528. In addition, the cooperation with QuoData GmbH has significantly improved the quality of our reports. Structure and design speak a clear language and the statistical explanations are focused on the essential. So you can fully concentrate on your interlaboratory test results and their evaluation.


  • The statistical methodology is determined and documented before the start of the proficiency testing.
  • The statistical evaluation is in accordance with ISO 13528:2015-08
  • Usually, the robust statistical methodology Q/Hampel is used.
  • In exceptional cases, a conventional statistical methodology can be used as well
  • The evaluation of the laboratory’s performance is based on z- / z’ scores or z/ zu‘ scores