Single Aliquot Regeneration (SAR) protocol has been routinely used to estimate palaeodose for sediment samples. However, it was observed that significant changes in the optically stimulated luminescence (OSL) sensitivity occur during read out of the natural OSL and that the current SAR protocol does not take into account these changes (Singhvi et al., 2011). It was suggested that if not corrected, this change of OSL sensitivity would lead to substantive systematic offsets in ages based on the conventional SAR protocol. To circumvent this issue of sensitivity change of OSL, a natural correction factor based SAR (NCF-SAR) measurement protocol and a correction procedure was suggested by Singhvi et al. (2011) with an implicit but a reasonable assumption that the sensitivity of 110 °C TL peak of quartz correlates with the OSL sensitivity. Use of this correction resulted in reduced over-dispersion in paleodoses and additionally provided a satisfactory way to deal with samples, where natural signal was significantly higher than the saturation value of the regenerated signal.

As a logical extension of this work, similar sensitivity changes in the OSL from single grains of quartz were examined and, their impact on the accuracy and reliability of single grain based SAR ages is discussed in this contribution. About ∼200 single grains each from 9 samples of diverse depositional environments were analysed and the NCF of each grain was measured. The single grain NCF’ [=(1/NCF)] values varied from 0.7 to 20. Of these ∼50% grains had sensitivity changes in the range of 0.7–1.3. The results indicated that, 1) the brighter grains (photon counts > 1000 c/s in a standard Risoe reader) had NCF′ closer to 1, though significant outliers did exist, 2) the distribution of NCF′ was positively skewed with significant number of values greater than one and, 3) the averaged single grain and multigrain NCF’ values were different, suggesting that in the case of multigrain aliquots, sensitivity changes of dim grains, on account of their larger numbers, collectively contributed significantly to the light sum in OSL.

常规使用等分试样再生（SAR）协议来估算沉积物样品的古菌糖。然而，据观察，在读出天然OSL的过程中，光学刺激的发光（OSL）灵敏度发生了显着变化，并且当前的SAR协议未考虑这些变化（Singhvi等，2011）。有人建议，如果不纠正，OSL灵敏度的这种变化将导致基于常规SAR协议的年龄出现实质性的系统性偏移。为了规避OSL灵敏度变化的问题，Singhvi等人提出了一种基于自然校正因子的SAR（NCF-SAR）测量协议和校正程序。（2011年）使用一个隐含但合理的假设，即石英的110°C TL峰的灵敏度与OSL灵敏度相关。

作为这项工作的逻辑扩展，研究了来自单晶石英的OSL中类似的灵敏度变化，并在此贡献中讨论了它们对基于单晶SAR年龄的准确性和可靠性的影响。对来自9种不同沉积环境样品的约200个单晶进行了分析，并测量了每个晶粒的NCF。单晶NCF'[=（1 / NCF）]的值在0.7到20之间变化。在这50％的晶粒中，灵敏度变化范围为0.7-1.3。结果表明，1）较亮的颗粒（标准Risoe读取器中的光子计数> 1000 c / s）的NCF'接近1，尽管确实存在明显的离群值； 2）NCF'的分布正偏斜，且数量明显大于1的值； 3）平均单粒和多粒NCF'值不同，