Foliage and Litterfall Ringtest and QA/QC Information

The Needle and Leaf Interlaboratory Comparison Test programme runs every year. The normal procedure is:

• Informing the possible participating labs and NFCs (every year - e.g. 2021, 2022, 2023, ...)
• Registration of the participants via internet (until July)
• Distribution of the test samples and the invoice (July-August)
• Data submission by the labs (August-December)
• Deadline of data submission (end of December)
• Results (January - next year)
• Re-qualification process finished (September - next year)
• Re-qualification confirmed - successful participation in next ringtest

When a lab did not qualify and did not make efforts to improve the data quality, the PCC will send a letter to the respective National Focal Centre informing it that the data may not be used for evaluations at European level.

The ringtest is financed by a participation fee, advertising and the preparation of ringtest samples by the participants. Please, keep in mind that the submission of the monitoring results to the PCC database is only possible if your lab participated in the ringtest for all submitted parameters. Results of the ringtests can be found under ringtest reports.

• Instructions for ringtest sample preparation
• Web interface for registration and data submission
• Evaluation procedure
• Parameters and evaluation limits
• Excel file for requalification
• Last requalification status