Capability of commercial trackers as compensators for the absolute refractive index of air

A suite of measurements of refractive index $$n(p,\ T_{90})$$ n ( p , T 90 ) is reported for gas phase ordinary water H$$_2$$ 2 O and heavy water D$$_2$$ 2 O. The methodology is optical refractive index gas metrology, operating at laser wavelength $$633\ \text {nm}$$ 633 nm and covering the range $$(293< T_{90} < 433)\ \text {K}$$ ( 293 < T 90 < 433 ) K and $$p < 2\ \text {kPa}$$ p < 2 kPa . A key output of the work is the determination of molar polarizabilities $$A_{\text {R}} = 3.7466(18) \cdot [1 + 1.5(6) \times 10^{-6} (T/\text {K} - 303) ]\ \text{cm}^3 \cdot \text{mol}^{-1}$$ A R = 3.7466 ( 18 ) · [ 1 + 1.5 ( 6 ) × 10 - 6 ( T / K - 303 ) ] cm 3 · mol - 1 for ordinary water, and $$A_{\text {R}} = 3.7135(18) \cdot [1 + 4.4(10) \times 10^{-6} (T/\text {K} - 303) ]\ \text{cm}^3 \cdot \text{mol}^{-1}$$ A R = 3.7135 ( 18 ) · [ 1 + 4.4 ( 10 ) × 10 - 6 ( T / K - 303 ) ] cm 3 · mol - 1 for heavy water, with the numbers in parentheses expressing standard uncertainty. For heavy water, this work appears to be only the second gas phase measurement to date. For both ordinary and heavy water, this work agrees within $$0.15\ \%$$ 0.15 % with recent ab initio theoretical results for $$A_{\text {R}}$$ A R , but the comparison is affected by imperfect knowledge of dispersion. For ordinary water, the close agreement between the present work and theory suggests problems at the $$2\ \%$$ 2 % level in the low density limit of the reference formulation for refractivity.

show abstract

Improved and Always Improving: Reference Formulations for Thermophysical Properties of Water

Harvey

Hrubý

Meier

2023

Journal of Physical and Chemical Reference Data

View full text Add to dashboard Cite

This Review presents the state of knowledge of the thermophysical properties of water in all its phases and the reference formulations that provide standardized, recommended values of these properties for science and industry. The main focus is the standard formulations adopted by the International Association for the Properties of Water and Steam (IAPWS), but some properties are covered for which IAPWS has not yet adopted recommendations. It is emphasized that, despite many advances over the last 100 years, there is room for further improvement, and current weaknesses and opportunities for advancing knowledge are discussed. Particular attention is given to the formulation for thermodynamic properties of fluid water known as IAPWS-95, which is planned to be replaced in the coming years. Additional topics include properties of heavy water and seawater and the growing ability of molecular modeling to provide properties at conditions where experimental measurements are difficult or inaccurate.

show abstract

Capability of commercial trackers as compensators for the absolute refractive index of air

Cited by 5 publications

References 45 publications

Optical $$n(p,\ T_{90})$$ Measurement Suite 1: He, Ar, and N$$_2$$

Optical $$n(p,\ T_{90})$$ Measurement Suite 1: He, Ar, and N$$_2$$

Optical $$n(p,\ T_{90})$$ Measurement Suite 2: H$$_2$$O and D$$_2$$O

Improved and Always Improving: Reference Formulations for Thermophysical Properties of Water

Contact Info

Product

Resources

About