C date dating
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 .
Following this intercomparison, a meeting was held in Turin in September-October 1986 at which seven radiocarbon laboratories (five AMS and two small gas-counter) recommended a protocol for dating the shroud. The samples were then taken to the adjacent Sala Capitolare where they were wrapped in aluminium foil and subsequently sealed inside numbered stainless-steel containers by the Archbishop of Turin and Dr Tite.
In October 1987, the offers from three AMS laboratories (Arizona, Oxford and Zurich) were selected by the Archbishop of Turin, Pontifical Custodian of the shroud, acting on instructions from the Holy See, owner of the shroud. Samples weighing 50 mg from two of the three controls were similarly packaged.
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.
On the basis of the stylistic details and the historical evidence the cope could be dated at ~ AD 1290 - 1310 (reign of King Phillipe IV).
Because it was not known to what degree dirt, smoke or other contaminants might affect the linen samples, all three laboratories subdivided the samples, and subjected the pieces to several different mechanical and chemical cleaning procedures.
Vial of Musée des Tissues and Centre International d'Étude des Textiles Anciens in Lyon), Dr M. Tite of the British Museum, representatives of the three radiocarbon-dating laboratories (Professor P. (With unravelled or shredded samples, pretreatment cleaning would have been more difficult and wasteful.) Because the shroud had been exposed to a wide range of potential sources of contamination and because of the uniqueness of the samples available, it was decided to abandon blind-test procedures in the interests of effective sample pretreatment.To confirm the feasibility of dating the shroud by these methods an intercomparison, involving four AMS and two small gas-counter radiocarbon laboratories and the dating of three known-age textile samples, was coordinated by the British Museum in 1983. The strip came from a single site on the main body of the shroud away from any patches or charred areas.