Radiocarbon laboratory quality assurance programme

English Heritage summaries. 2003/2004

The fifth international radiocarbon inter-comparison (VIRI) continues the tradition of TIRI (third) and FIRI (fourth) inter-comparisons (Scott 2003) and operates as an independent check on radiocarbon laboratory procedures, in addition to any within-laboratory procedures for quality assurance.  VIRI is a 4-year project, with the first suite of samples, grain, sent out in September 2004 (Scott et al 2007), and the second suite, bone, sent out in December 2005. The final set of samples, including peat, wood, charcoal and shell with a range of ages was distributed in 2007, with results due in mid-2008.

VIRI forms an important part of a laboratory’s quality assurance procedure, since firstly it allows the assessment of accuracy.  Accuracy of the measurement refers to the deviation (difference) of the measured value from the true value (or consensus value in the case of VIRI).  Secondly, VIRI can be used to assess whether the laboratory uncertainty estimate is realistic, since VIRI provides a set of independent measurements obtained by the ‘same’ method on identical samples in different laboratories. 

Over the four year programme, more than 70 laboratories have taken part in VIRI. The overall assessment of performance will be reported in 2009.

Scott, E M, 2003 The Third International Radiocarbon Intercomparison (TIRI) and the Fourth International Radiocarbon Inter-comparison (FIRI), 1990-2002: results, analyses, and conclusions, Radiocarbon, 45, 135–408

Scott, E M, Gordon, G T, Naysmith, P, Bryant, C, and O’Donnell, D, 2007 A report on Phase 1 of the 5th International Radiocarbon Intercomparison (VIRI), Radiocarbon, 49, 409-26

This page was published on 06/05/2008