SLAP is one of the two calibration materials for the isotopic water scale. By consensus the established δ¹⁸O value is −55.5‰, although several expert laboratories measure significantly more negative δ¹⁸O_SLAP values. The real δ¹⁸O_SLAP value as such does not influence the isotopic water scale; however, knowledge of the size of isotopic scale contraction in stable isotope measurements is vital for second-order isotopes. This study describes the quantification of δ¹⁸O_SLAP with respect to δ¹⁸O_VSMOW.

中文翻译：

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SLAP 相对于 VSMOW 的绝对 δ18O 值显示出比之前建立的值低得多的值

SLAP是同位素水标尺的两种校准材料之一。尽管一些专家实验室测得的δ ^{18 O} _SLAP值明显更负，但根据共识，确定的δ ¹⁸ O值为 -55.5‰。真实的δ ¹⁸ O _SLAP值本身并不影响同位素水标度；然而，了解稳定同位素测量中同位素尺度收缩的大小对于二阶同位素至关重要。本研究描述了δ ¹⁸ O _SLAP相对于δ ¹⁸ O _VSMOW的量化。