proficiency testing round 

Synonym: PT round
https://doi.org/10.1351/goldbook.08103
Single complete sequence from distribution of proficiency test items to reporting of the evaluation results to the participants.
Source:
PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1034 (https://doi.org/10.1515/pac-2019-0819)