ogawa_1958 ========== M\. Ogawa and G\. R\. Cook, "Absorption coefficients of O3 in the vacuum ultraviolet region", J\. Chem\. Phys\. 28, 173 \(1958\) `Source record `__ · :doc:`Catalogue ` · :doc:`Review register ` DOI: `10\.1063/1\.1744071 `__ **Source kind:** measurement **Recorded technique:** Photoelectric absorption, 'preliminary measurements' 520\-1350 A\: normal\-incidence vacuum spectrograph \(30000 lines/inch grating, 50 cm radius, 500 um primary slit\) with an exit slit moved along the Rowland circle; a repetitive condensed spark in air \+ He \(about 200 um Hg\) as a line source; a sodium\-salicylate\-coated photomultiplier\. Ozone from an ozonizer fed with extra\-dry O2 \(0\.4 % unspecified impurities\), trapped as a liquid, evaporated into a flask and flowed continuously through the absorption tube, the relative pressure set by glass capillaries\. The pressure itself was not measured\: only relative coefficients \(p\. 173\)\. **Materials in structured entries:** O3 **Dataset quantities:** absorption\_cross\_section **Contents:** 2 datasets; 0 formulas. Curation notes -------------- Identity checked against the first page \(PDF page 2, journal p\. 173\)\: Ogawa and Cook, 'Absorption Coefficients of O3 in the Vacuum Ultraviolet Region', J\. Chem\. Phys\. 28, 173 \(1958\); the library's observed title lost the subscript \('O' for 'O3'\)\. Journal pages 173\-174 = PDF pages 2\-3 \(page 1 is the publisher's cover; page 2 begins with the end of the preceding letter\)\. O3 only\. Quantity \(p\. 173\)\: Lambert's law I = I0 exp\(\-mu x\), 'x cm of gas at standard conditions \(0 C and 760 mm of Hg\)'\: mu is the natural\-log absorption coefficient at the ideal\-gas Loschmidt density\. The datasets keep mu \(cm^\-1\) with scale = 1e18 / n0, n0 = 101325 Pa / \(k\_B 273\.15 K\) = 2\.6867801e19 cm^\-3, to the cross section per molecule in Mb \(as watanabe\_1953\)\. Wavelengths in A, 'approximate', vacuum \(a vacuum spectrograph\)\. Temperature not stated \(the flow of gas evaporated from the liquid; room temperature presumably; the Mainz atlas's 295 K is not in the paper\)\. Absolute scale \(p\. 173\)\: 'only relative absorption coefficients were directly determined'; with the Lyman alpha \(1216 A\) value set to 500 arbitrary units, the absolute values follow from 'the absorption coefficient at the Lyman alpha line which was carefully measured by Tanaka, Inn, and Watanabe \[tanaka\_1953\] \.\.\. based on mu = 614 cm^\-1 at 1216 A as estimated from Tanaka's graph' \(Tanaka's text states no Lyman alpha value\: 614 is read from their Fig\. 1\)\. So the whole absolute column is Tanaka's scale times Ogawa's relative shape; Tanaka estimates their own 'combined experimental error would be as high as 10 percent'\. Accuracy \(p\. 173\)\: five points in Tanaka's region \(1060\-1350 A\: rows 1305, 1243, 1216, 1135, 1085\) 'were in good agreement with this curve \.\.\. Therefore the error in the present experiment was estimated to be below 20 percent' \(recorded as a 20 % bound on the absolute values\)\. The percent\-error column of Table I is the precision of the relative coefficients \(the relative dataset carries the printed \+\- as sigma\)\. Text \(p\. 173\-174\)\: the continuous absorption \(Fig\. 1's dashed curve through the lower points\) 'increases rapidly from about 960 A and reaches a maximum of 980 cm^\-1 at about 750 A; then it gradually decreases to 770 cm^\-1 at 525 A'; 'between 750 and 520 A some weak bands overlap this continuum' \(the points above the dashed curve\)\. The ionisation potential 12\.80 eV \(950 A\) of Herron and Shiff \(reproduced, not extracted\)\. These readings of the smoothed continuum are figure\-level and are not extracted\. Checks made on Table I\: absolute / relative = 1\.2266\-1\.2316 for every row \(614/500 = 1\.228\), except 1243 A \(288 / 232 = 1\.241\: 232 x 1\.228 = 285\); the percent errors are the \+\- over the relative value except 1305 A \(5\.8/190 = 3\.1 %, printed 3\.3\) and 617 A \(22\.0/762 = 2\.9 %, printed 2\.7\)\. No correction is certain; the printed values are kept \(TC\-179\)\. **Recorded bibliographic identity status:** VALIDATED\_WITH\_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents. Datasets -------- ogawa\_1958/absolute ~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "absolute", "material": "O3", "file": "O3/ogawa_1958__absolute.csv", "table": "tbl_987cd6327574", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.03721927208, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "primary", "uncertainty": { "relative": 0.2, "level": "bound" } } Table I, last column\: the absolute absorption coefficient mu \(cm^\-1, 0 C and 760 mm Hg\), 24 lines 526\-1305 A; scale = 1e18 / n0 to Mb\. Scaled to Tanaka's 614 cm^\-1 at 1216 A \(the row 1216 is that anchor, not a measurement of the absolute value\)\. 'Error \.\.\. estimated to be below 20 percent' \(p\. 173\), recorded as a bound\. Line\-source values at about 0\.5\-1 A resolution \(not stated\)\: the rows 703\-526 A above Fig\. 1's dashed continuum include weak bands\. Temperature not stated\. ogawa\_1958/relative ~~~~~~~~~~~~~~~~~~~~ .. code-block:: text { "id": "relative", "material": "O3", "file": "O3/ogawa_1958__relative.csv", "table": "tbl_987cd6327574", "quantity": "absorption_cross_section", "unit": "Mb", "scale": 0.045705266114, "abscissa_unit": "angstrom", "wavelength_medium": "vacuum", "use": "check", "uncertainty": { "column": true, "level": "not stated" } } Table I, second column\: the relative absorption coefficient \(Lyman alpha = 500\), with the printed \+\- as sigma \(level not stated; the precision of the relative shape\)\. scale = \(614 / 500\) x 1e18 / n0, the paper's own conversion to the absolute coefficient, then to Mb\. The same measurements as 'absolute' \(a check of the per\-point precision, never fitted beside it\)\. 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.