Calibration of radiocarbon dates. It was unclear for some time whether the wiggles were real or not, but they are now well-established. Because of this, radiocarbon chemists are continually developing new methods to more effectively clean materials. The calculations given above produce dates in radiocarbon years: The dating framework provided by radiocarbon led to a change in the prevailing view of how innovations spread through prehistoric Europe. Both beta counting and AMS results have to be corrected for fractionation.
Many labs now use an Accelerator Mass Spectrometer AMSa machine that can detect and measure the presence of different isotopes, to count the individual 14 C atoms in a sample.
Libby estimated that the steady-state radioactivity concentration of exchangeable carbon would be about 14 disintegrations per minute dpm per gram. It was an anxious time for scientists whose reputation for accurate work was on the line. The deepest parts of the ocean mix very slowly with the surface waters, and the mixing is uneven. In this method, the carbon sample is first converted to carbon dioxide gas before measurement in gas proportional counters takes place. Much of the initial interest in carbon came from archeology, for the isotope could assign dates to Egyptian mummies and the like. Archaeology and other human sciences use radiocarbon dating to prove or disprove theories.