Although the dating of objects by the Carbon 14 technique is well known and has had great success, it does have limitations. The method cannot date objects more than 60,000 years old, several grams of material are needed and the counting needs to be carried out over quite a long period -- 10 hours would be typical. Unfortunately conventional mass spectrometers are not sufficiently sensitive to detect the small proportion of the radioactive isotopes present in normal samples. The use of an accelerator, might seem expensive compared with traditional techniques, in the experiment is much shorter; which might well make it competitive economically.