Dose response curves of three methods applied for <i>D</i>_e determination.

<p>(a) Exemplary SAR dose response curve for one aliquot of sample BT1611. (b) Changes in UVTL dose sensitivity in the course of the five SAR cycles, as deduced from the test dose (<i>T</i>_x) measurements. Note that the relative change in sensitivity does not exceed ~5%. (c) MAAD dose response curve for sample BT1612. (d) Plot of UVTL SARA data for sample BT1612. The <i>D</i>_e values shown on the y-axis were obtained by running a SAR sequence of aliquots having received different additive β-doses, but without correction for sensitivity changes. The known additive β-doses are shown on the x-axis. The linear regression represents on the one hand the degree of sensitivity change during natural TL readout via its slope. On the other hand, it gives the true palaeodose by extrapolating it to the dose axis [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178545#pone.0178545.ref032" target="_blank">32</a>]. Data analysis was performed with several functions of the R package ‘Luminescence’ (v. 0.6.4) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178545#pone.0178545.ref029" target="_blank">29</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178545#pone.0178545.ref031" target="_blank">31</a>].