And carbon dating
Background radiocarbon activity is measured, and the values obtained are deducted from the sample’s radiocarbon dating results.
Background samples analyzed are usually geological in origin of infinite age such as coal, lignite, and limestone.
Liquid scintillation counting is another radiocarbon dating technique that was popular in the 1960s.
These values have been derived through statistical means.
By knowing how much carbon 14 is left in a sample, the age of the organism when it died can be known.