On a monthly basis, certified laboratories participate in a Samples Unknown program to verify the accuracy of their instruments. Here is a quick overview of the program:

  • On Monday of the second full week, the Samples Unknown supplier sends two duplicate sets of 12 samples to the participating laboratories.
  • By that Friday night at midnight EST, each laboratory is required to analyze the 24 samples and submit the results to the Samples Unknown web site.
  • On Monday of the third full week, the laboratory auditor downloads the raw data from the web site and analyzes the components.
  • Once the analysis is complete, reports showing the deviations between the data submitted and the reference results are emailed to each participating laboratory.


This page is a link to the Samples Unknown web site where the raw data is entered and the certification reports are generated. It should only be accessed by laboratories participating in the program and will not provide useful information to other parties.

Click here to go to the 2008 Samples Unknown Schedule (Printable PDF).

Click here to go to the Samples Unknown web site.