Delta Values
For all integrals, \(\delta\)-values can be calculated automatically
as described in the usage documentation.
Delta values are always calculated (1) with respect to the major isotope
and (2) using the NIST database of the
iniabu package.
If no value can be calculated, i.e.,
because the isotope is unknown to iniabu
or because
the natural abundance of the specified isotope is unknown,
np.nan
will be returned as the \(\delta\)-value.
Note
All \(\delta\)-values are reported in per mil (‰).
Calculation \(\delta\)-value
Be \(i\) and \(j\) the number of counts in the nominator and denominator isotopes, respectively, and \(r\) the NIST isotopic ratio of the same isotopes. The \(\delta\)-value can then be calculated as:
Uncertainties
Be \(\sigma_i\) and \(\sigma_j\) the uncertainties of values \(i\) and \(j\), respectively. The uncertainty of the \(\delta\)-value \(\sigma_{\delta}\) can be calculated as: