egan_2024_correction ==================== P\. F\. Egan and Y\. Yang, "Correction to\: Optical n\(p, T90\) Measurement Suite 1\: He, Ar, and N2", Int\. J\. Thermophys\. 45, 177 \(2024\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1007/s10765\-024\-03473\-6 `__ **Source kind:** measurement **Recorded technique:** The authors' correction to egan\_2023 \(Fabry\-Perot cavity refractometry of Ar and N2 at 632\.9908 nm\)\: the treatment of the Gouy phase shift, and so the refractometer working equation, Eq\. \(1\) of the original; no new measurement is described\. **Materials in structured entries:** None recorded. **Dataset quantities:** None recorded. **Contents:** 0 datasets; 0 formulas. Curation notes -------------- Two pages \(published online 28 November 2024\); identity VALIDATED\_WITH\_WARNINGS in the library \(the title's math is garbled in the metadata; DOI, journal, authors and the DOI of the corrected article printed on p\. 1 agree\)\. Read in full \(2026\-09\-29\)\. WHAT IT CORRECTS \(pp\. 1\-2\)\: the original stated that the cavity beam waist stays constant when the refractive index rises; by Kogelnik and Li's Eqs\. \(1\)\-\(2\) the waist depends on the wavelength in the medium, so the Gouy phase shift does not depend on the index\. The corrected working equation, Eq\. \(3\)\: n \- 1 = \(Delta f \+ kappa Delta p nu\_gas\) / \[nu\_gas \(1 \- kappa Delta p\) \+ eps\_tau \(nu\_gas \- nu\_c\)\], without the factor \(1 \+ eps\_d\) in the denominator, valid for constant L/r under uniform pressure\. THE EFFECT \(p\. 2\)\: 'The reported molar refractivities for argon and nitrogen were fractionally small by 0\.3 x 10^\-6 A\_R', an order of magnitude below their combined standard uncertainty \(3\.1e\-6\)\. Applied as \[\[errata\]\] of egan\_2023's A\_R\_Ar and A\_R\_N2 \(4\.195735 \-\> 4\.1957363, 4\.446175 \-\> 4\.4461763 cm^3/mol; the correction's factor applied, not printed values\)\. A\_theta \(N2's temperature coefficient\) and the helium compressibility calibration are not addressed\: a relative scale factor common to all isotherms leaves A\_theta unchanged to first order, but the correction does not say so\. NOT CHECKED\: whether yang\_2025 \(same laboratory and cavity, published June 2025\) used the corrected working equation, and whether lang\_2026's reproduced Egan\-Yang value \(egan\_yang\_303K\) is the corrected one \(TC\-724\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- No datasets are recorded. Formulas -------- No formulas are recorded. Corrections ----------- No dataset errata are recorded in this source record. Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register ` for the checks and decisions.