Dating through the ages
Measuring the intensity of the luminescence can determine how much time has passed since the last time the object was heated.
The light is proportional to the amount of radiation absorbed since the material was last heated.
Thermoluminescence dating is generally not very accurate.
The accuracy of thermoluminescence dating is only about 15% for a single sample and 7 to 10% for a suite of samples in a single context.
Therefore, in archaeology, thermoluminescence dating works best for ceramics, cooking hearths, incidentally fire-cracked rocks, and deliberately fire-treated rocks, such as flint or chert.Indeed, the figure shows an automatic instrumentation which allows measurement of thermoluminescence light from samples and also the determination of the dose rate per year.This last procedure involves the use of a radioactive source, though very weak.Then we need to correlate thermoluminescence light to radiation dose rate per year which the sample has received since its last clock resetting event.Eventually, we will follow this formula to found out how many years old the sample is: Age (year) = accumulated dose / dose rate per year Thermoluminescence dating can be performed only in a specialized laboratory which will have a chemical section for the treatment of the samples with reagents and a radiation hazard restricted area.