Carbon dating shroud of teran
But the three laboratories undertook not to compare results until after they had been transmitted to the British Museum.
The final third was given a strong treatment, using the same procedure except that hot (80° C) 5% HCL and 2.5% Na OH were used.All laboratories examined the textile samples microscopically to identify and remove any foreign material.The Oxford group cleaned the samples using a vacuum pipette, followed by cleaning in petroleum ether (40° C for 1 h) to remove lipids and candlewax, for example.Among those present when the sample as cut from the shroud were Cardinal Anastasio Ballestrero (Archbishop of Turin), Professor L. The laboratories were not told which container held the shroud sample.Gonella (Department of Physics, Turin Polytechnic and the Archbishop's scientific adviser), two textile experts (Professor F. Because the distinctive three-to-one herringbone twill weave of the shroud could not be matched in the controls, however, it was possible for a laboratory to identify the shroud sample.Even for the first investigation, there was a possibility of using radiocarbon dating to determine the age of the linen from which the shroud was woven.
The size of the sample then required, however, was ~500cm, which would clearly have resulted in an unacceptable amount of damage, and it was not until the development in the 1970s of small gas-counters and accelerator-mass-spectrometry techniques (AMS), requiring samples of only a few square centimetres, that radiocarbon dating of the shroud became a real possibility. The shroud was separated from the backing cloth along its bottom left-hand edge and a strip (~10 mm x 70 mm) was cut from just above the place where a sample was previously removed in 1973 for examination.
The Arizona group split each sample into four subsamples.
One pair of subsamples from each textile was treated with dilute HCL, dilute Na OH and again in acid, with rinsing in between (method a).
Photography of the shroud by Secondo Pia in 1898 indicated that the image resembled a photographic 'negative' and represents the first modern study.
Subsequently the shroud was made available for scientific examination, first in 19 by a committee appointed by Cardinal Michele Pellegrino .
The Zurich group first split each ultrasonically cleaned sample in half, with the treatment of the second set of samples being deferred until the radiocarbon measurements on the first set had been completed.