C-12 and C-13 are stable but C-14 decays at a known rate, with a half-life of 5,568 years.
University of Leicester archaeologists took four small samples from one of the ribs of the Greyfriars skeleton and sent them to two specialist units with the facilities to analyse them: the Scottish Universities Environmental Research Centre (SUERC) at the University of Glasgow, and the Oxford Radiocarbon Accelerator Unit, part of the University of Oxford’s Research Laboratory for Archaeology and the History of Art.
As with our other forwarding facilities, samples sent to the North Sydney office are sent overnight through expedited courier services at the company’s expense,” Beta Analytic director Thierry Tamers announces.
The new regional forwarding facilities are part of Beta Analytic’s effort to strengthen its reputation as the world’s largest commercial radiocarbon dating lab.
Non-marine as well as marine and terrestrial sediments can be dated using this method.
The rate of bombardment is greatest near the poles, where the Earth's magnetic field is dipping into the Earth and therefore does not deflect incoming cosmic rays.
Suitable specimens are selected by picking through the residue.
Price depends on the nature of the material and turnaround time required; the basic price for analysis with a turnaround time of less than 3 weeks is £395 plus the cost of sample preparation. C ratio therefore remains in equilibrium with the atmosphere.
However, upon death there is no further uptake of carbon and the 14C decays to 12N with a half life of 5730 years.
Measurement of the amount of C remaining in a dead organism will therefore give the date of its death.