Thermoluminescence dating range
The TL laboratory at Daybreak was established in 1977 to make TL available to the art community in general. Studies at Oxford back in the 70s on Romano-British pottery indicated that when all quantities entering the age equation are measured, the TL date of a single potsherd will typically fall within 15 per cent of the known date.When dates of a number of sherds associated together are averaged, the error is reduced typically to 7-10 per cent. The succeeding 30 years, and increased understanding of the dosimetry, have not brought much improvement.
Finally, one has to make the measurements regardless of whether the TL of the clay is well-behaved or not.
It is an absolute dating method, and does not depend on comparison with similar objects (as does obsidian hydration dating, for example).