Compare and contrast radiocarbon dating and thermoluminescence problem updating windows vista service pack 2
Results of carbon-14 dating are reported in radiocarbon years, and calibration is needed to convert radiocarbon years into calendar years.
Uncalibrated radiocarbon measurements are usually reported in years BP where 0 (zero) BP is defined as AD 1950.
It is also worth noting that the half-life used in carbon dating calculations is 5568 years, the value worked out by chemist Willard Libby, and not the more accurate value of 5730 years, which is known as the Cambridge half-life.
Although it is less accurate, the Libby half-life was retained to avoid inconsistencies or errors when comparing carbon-14 test results that were produced before and after the Cambridge half-life was derived.
It is also called “radiocarbon” because it is unstable and radioactive relative to carbon-12 and carbon-13.
Carbon consists of 99% carbon-12, 1% carbon-13, and about one part per million carbon-14.
Due to this and some other advantages OSL is also being used for various applications in radiation dosimetry, such as personnel and environmental dosimetry, retrospective/ accident dosimetry and medical dosimetry.
But this method is also useful in many other disciplines.and later investigation of its suitability for personnel dosimetry using pulsed OSL (POSL) technique of stimulation by Akselrod and Mc Keever, resulted in the development of a personnel dosimetry system based on Al : C OSL phosphor.Therefore, thrust of modern luminescence dosimetry development is more towards OSL.BP stands for “Before Present” or “Before Physics” as some would refer to it.It should be noted that a BP notation is also used in other dating techniques but is defined differently, as in the case of thermoluminescence dating wherein BP is defined as AD 1980.
For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.