How does c14 dating work

Burning the samples to convert them into graphite, however, also introduces other elements into the sample like nitrogen 14.When the samples have finally been converted into few milligrams of graphite, they are pressed on to a metal disc.Mass spectrometers detect atoms of specific elements according to their atomic weights.They, however, do not have the sensitivity to distinguish atomic isobars (atoms of different elements that have the same atomic weight, such as in the case of carbon 14 and nitrogen 14—the most common isotope of nitrogen).At this stage, other negatively charged atoms are unstable and cannot reach the detector.

At the end of an AMS run, data gathered is not only the number of carbon 14 atoms in the sample but also the quantity of carbon 12 and carbon 13.There are two techniques in measuring radiocarbon in samples—through radiometric dating and by Accelerator Mass Spectrometry (AMS).The two techniques are used primarily in determining carbon 14 content of archaeological artifacts and geological samples.Accelerator mass spectrometers need only as little as 20 milligrams and as high as 500 milligrams for certain samples whereas conventional methods need at least 10 grams in samples like wood and charcoal and as much as 100 grams in bones and sediments.Accelerator mass spectrometers typically need sample sizes lesser than conventional methods by a factor of 1,000. Hence, because of its ability to analyze samples even in minute amounts, accelerator mass spectrometry is the method of choice for archaeologists with small artifacts and those who cannot destroy very expensive or rare materials.

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