When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14 C it contains begins to decrease as the 14 C undergoes radioactive decay.
Photosynthesis is the primary process by which carbon moves from the atmosphere into living things.
In addition, anticoincidence detectors are used; these record events outside the counter, and any event recorded simultaneously both inside and outside the counter is regarded as an extraneous event and ignored.
Occasionally the digitization process introduces transcription errors or other problems.
Description: Like gas counters, liquid scintillation counters require shielding and anticoincidence counters. Contamination with modern carbon causes a sample to appear to be younger than it really is: