Sentences with phrase «calibration curve range»

I had a Savina placenta sample which of course was miles out of the standard solutions calibration curve range, and using the equation for the line got a result.

Not exact matches

The measurement process does not allow calendar ages in a range where the calibration curve is flat to be distinguished.

Now we'll take the 1000 — 1100 years range, which asymmetrically covers a steep region in between two plateaus of the calibration curve.

Actually the calibration curve beyond the treering range (ca 12 000 BP) is very decidedly shaky.

For this purpose, it would not be necessary to draw true ages from the full prior, but only well on either side of the selected range, in order to accommodate possible observation error and the distortion of the calibration curve.

I've picked periods representing both ranges over which the calibration curve is mainly flattish and those where it is mainly steep.

Since the calibration curve error appears small in relation to 14C determination error, and typically only modestly varying over the 14C determination error range, I will make the simplifying assumption that it can be absorbed into an increased 14C determination error.

But it also can't provide conclusive evidence for the calendar year having any other value, unless there's a calendar year for which the calibration curve is nearly vertical, covering the entire range of carbon - 14 ages that are plausible given the measurement.

Your Fig. 6 shows that the uniform calendar age prior does terribly when the true calendar age is known to be in the range 1000 - 1100 years, using your hypothetical calibration curve.

For both variants of the uniform prior subjective Bayesian method, probability matching is nothing like exact except in the unrealistic case where the sample is drawn equally from the entire calibration range — in which case over-coverage errors in some regions on average cancel out with under - coverage errors in other regions, probably reflecting the near symmetrical form of the stylised overall calibration curve.

The reason for the form here of Jeffreys» prior is fairly clear — where the calibration curve is steep and hence its derivative with respect to calendar age is large, the error probability (red shaded area) between two nearby values of t14C corresponds to a much smaller ti range than when the derivative is small.