At the same time, the British Museum was invited to help in the certification of the samples provided and in the statistical analysis of the results. The age of the shroud is obtained as AD 1260-1390, with at least 95% confidence. The three containers containing the shroud (to be referred to as sample 1) and two control samples (samples 2 and 3) were then handed to representatives of each of the three laboratories together with a sample of the third control (sample 4), which was in the form of threads.The procedures for taking the samples and treating the results were discussed by representatives of the three chosen laboratories at a meeting at the British Museum in January 1988 and their recommendations = standard deviation) errors, of the Shroud of Turin and control samples, as supplied by the three laboratories (A, Arizona; O, Oxford; Z, Zurich) (See also Table 2.) The shroud is sample 1, and the three controls are samples 2-4. The sampling of the shroud took place in the Sacristy at Turin Cathedral on the morning of 21 April 1988. All these operations, except for the wrapping of the samples in foil and their placing in containers, were fully documented by video film and photography.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 .Zurich precleaned the sample in an ultrasonic bath.After these initial cleaning procedures, each laboratory split the samples for further treatment.
After many journeys the shroud was finally brought to Turin in 1578 where, in 1694, it was placed in the royal chapel of Turin Cathedral in a specially designed shrine.But the three laboratories undertook not to compare results until after they had been transmitted to the British Museum.Also, at two laboratories (Oxford and Zurich), after combustion to gas, the samples were recoded so that the staff making the measurements did not know the identity of the samples. On the basis of the Islamic embroidered pattern and Christian ink inscription, this linen could be dated to the eleventh to twelfth centuries AD. Linen from the collection of the Department of Egyptian Antiquities at the British Museum, associated with an early second century AD mummy of Cleopatra from Thebes (EA6707).One-third received no further treatment, one-third was submitted to a weak treatment with 0.5% HCL (room temperature), 0.25% Na OH (room temperature) and again in acid, with rinsing in between.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.