Radiocarbon dating calibration
Cal Pal-Online is developed to give a quick reference.
Over the past decade we have witnessed a remarkable development and proliferation of accelerator mass spectrometers; these instruments have reduced the counting time by a factor of 100 and reduced the sample size by a factor of 1000 compared to the classic B-counting systems.
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.
It is estimated that nearly 90% of all measurements made at the more than 50 active accelerator mass spectrometry laboratories are radiocarbon dates.
This dramatic increase in the number of radiocarbon dates is driving the demand for a radiocarbon calibration program that spans the entire radiocarbon timescale from the present to 55,000 years BP.