That sample was divided among three radiocarbon dating laboratories and a reserved piece was set aside in case it was needed.
The labs, in turn, divided their pieces into sub-samples in order to run multiple tests.
Source: One Episcopalian on Faith Over and over, we read in newspapers and blogs that the shroud was carbon dated thus proving it was medieval.Sometimes, a reporter will mitigate by mentioning that some people question the results.To believe in the tests, we must also ignore Christopher Ramsey, the current head of the Oxford Radiocarbon Accelerator Unit, a lab that participated in the original carbon 14 dating of the Shroud.In March of 2008, he said that because of new information “further research is certainly needed.” He went on to say: It is equally important that experts assess and reinterpret some of the other evidence.They demonstrated that the sample area was significantly unlike the rest of the shroud.
In other words it is almost certain that the shroud itself was not carbon dated.
He found extraordinary evidence of medieval mending that explains the chemical differences.
He also found clear chemical reasons to believe that the cloth is several centuries older than the carbon dating results.
He fails to mention that the three labs performed the same test on pieces of the same sample.
They should have achieved near-identical results but in reality the results were statistically different enough to call the results into question.
With all of this evidence in hand, researchers combed records looking for other evidence.